Tue·Nov 22, 2022Tuesday·November 22, 2022

1. 01*

   QCD vacuum replicas are metastable

   Pedro Bicudo🇵🇹 · José Emílio Ribeiro🇵🇹

   We study the meson spectra in the excited QCD vacua, denominated replicas. We find all mesons have real masses, with no tachyons, thus showing the QCD replicas are indeed metastable.

   hep-phEPJ Web Conf.(2022)·1 citation
2. 02*

   Quantum information and CP measurement in $H\to {\tau }^{+}{\tau }^{-}$ at future lepton colliders

   Mohammad Mahdi Altakach🇫🇷 · Priyanka Lamba🇵🇱 · Fabio Maltoni🇧🇪 · Kentarou Mawatari🇯🇵 · Kazuki Sakurai🇵🇱

   We introduce a methodology and investigate the feasibility of measuring quantum properties of tau lepton pairs in the $H\to {\tau }^{+}{\tau }^{-}$ decay at future lepton colliders. In particular, observation of entanglement, steerability and violation of Bell inequalities are examined for the ILC and FCC-ee. We find that detecting quantum correlation crucially relies on precise reconstruction of the tau lepton rest frame and a simple kinematics reconstruction does not suffice due to the finite energy resolution of the colliding beams and detectors. To correct for energy mismeasurements, a log-likelihood method is developed that incorporates the information of impact parameters of tau lepton decays. We demonstrate that an accurate measurement of quantum properties is possible with this method. As a by-product, we show that a novel model-independent test of CP violation can be performed and the CP-phase of $H\tau \tau$ interaction can be constrained with an accuracy comparable to dedicated analyses, i.e., up to $7.9^{\circ }$ and $5.4^{\circ }$ at ILC and FCC-ee, respectively.

   hep-phhep-exquant-phPRD(2023)·102 citations
3. 03*

   Non-unitary three-neutrino mixing in the early Universe

   Stefano Gariazzo🇮🇹 · Pablo Martínez-Miravé🇪🇸 · Olga Mena🇪🇸 · Sergio Pastor🇪🇸 · Mariam Tórtola🇪🇸

   Deviations from unitarity in the three-neutrino mixing canonical picture are expected in many physics scenarios beyond the Standard Model. The mixing of new heavy neutral leptons with the three light neutrinos would in principle modify the strength and flavour structure of charged-current and neutral-current interactions with matter. Non-unitarity effects would therefore have an impact on the neutrino decoupling processes in the early Universe and on the value of the effective number of neutrinos, $N_{\mathrm{eff}}$. We calculate the cosmological energy density in the form of radiation with a non-unitary neutrino mixing matrix, addressing the possible interplay between parameters. Highly accurate measurements of $N_{\mathrm{eff}}$ from forthcoming cosmological observations can provide independent and complementary limits on the departures from unitarity. For completeness, we relate the scenario of small deviations from unitarity to non-standard neutrino interactions and compare the forecasted constraints to other existing limits in the literature.

   hep-phastro-ph.COJCAP(2023)·14 citations
4. 04*

   {\tt ee$\in$MC}: Arbitrary Initial Spin States for the Production of ${\mathbf{e}}^{+}{\mathbf{e}}^{-}\to {\tau }^{+}{\tau }^{-}(\gamma )$ Events and the Impact on Spin Correlations

   Ian M. Nugent🇨🇦

   We present a modified spin algorithm, including spin correlations, which has been implemented in {\tt ee$\in$MC} for the simulation of $e^{+}{e}^{-}\to {\tau }^{+}{\tau }^{-}(\gamma )$ events with an arbitrary initial spin configuration. This algorithm is suitable for the proposed BELLE-II polarization upgrade to SuperKEKB, both for the ideal case and for the case where there are misalignments, radiative effects and allows for changing polarization conditions. The spin $1/2$ states of the polarized beams are constructed in terms of a super-positioning of the helicity states corresponding to the polarimetric-vector describing the overall beam polarization and implemented both through a modification of the initial state in the modified Altrelli-Parsis Density Function as well as a change of basis of the helicity states.

   hep-phhep-ex1 citation
5. 05*

   Branching Fractions of $B$ Meson Decays in Mesogenesis

   Gilly Elor🇩🇪 · Alfredo Walter Mario Guerrera🇮🇹

   Production of the matter-antimatter asymmetry in the $B$-Mesogenesis mechanism is directly related to the branching fraction of seemingly baryon number violating decays of $B$ mesons into a light Standard Model baryon and missing energy. Achieving the observed baryon asymmetry requires that the branching fraction for such decays be greater than about $10^{-7}-10^{-5}$. Experimental searches at $B$ Factories and Hadron Colliders target specific decay modes. Therefore, computing the exclusive branching fraction for each decay is a critical step towards testing Mesogenesis. In this work we use QCD Light Cone Sum Rules to compute the form factors and branching fractions of the various possible channels contributing to the baryon asymmetry. Using the results, we comment on implications for current and future experimental searches.

   hep-phhep-exJHEP(2023)·26 citations
6. 06*

   Enhancing Sensitivity to Leptonic CP Violation using Complementarity among DUNE, T2HK, and T2HKK

   Sanjib Kumar Agarwalla🇮🇳 · Sudipta Das🇮🇳 · Alessio Giarnetti🇮🇹 · Davide Meloni🇮🇹 · Masoom Singh🇮🇳

   After the landmark discovery of non-zero ${\theta }_{13}$ by the modern reactor experiments, unprecedented precision on neutrino mass-mixing parameters has been achieved over the past decade. This has set the stage for the discovery of leptonic CP violation (LCPV) at high confidence level in the next-generation long-baseline neutrino oscillation experiments. In this work, we explore in detail the possible complementarity among the on-axis DUNE and off-axis T2HK experiments to enhance the sensitivity to LCPV suppressing the ${\theta }_{23}-{\delta }_{\mathrm{CP}}$ degeneracy. We find that none of these experiments individually can achieve the milestone of 3$\sigma$ LCPV for at least 75% choices of ${\delta }_{\mathrm{CP}}$ in its entire range of $[-180^{\circ },180^{\circ }]$, with their nominal exposures and systematic uncertainties. However, their combination can attain the same for all values of ${\theta }_{23}$ with only half of their nominal exposures. We observe that the proposed T2HKK setup in combination with DUNE can further increase the CP coverage to more than 80% with only half of their nominal exposures. We study in detail how the coverage in ${\delta }_{\mathrm{CP}}$ for $\ge$ 3$\sigma$ LCPV depends on the choice of ${\theta }_{23}$, exposure, optimal runtime in neutrino and antineutrino modes, and systematic uncertainties in these experiments in isolation and combination. We find that with an improved systematic uncertainty of 2.7% in appearance mode, the standalone T2HK setup can provide a CP coverage of around 75% for all values of ${\theta }_{23}$. We also discuss the pivotal role of intrinsic, extrinsic, and total CP asymmetries in the appearance channel and extrinsic CP asymmetries in the disappearance channel while analyzing our results.

   hep-phhep-exphysics.ins-detEPJC(2023)·23 citations
7. 07*

   A Brief Review on Jet Substructure in Connection with Collider Phenomenology

   Nilanjana Kumar🇮🇳

   It is a challenge for the theoretical particle physicists to perform the phenomenology of the Beyond Standard Model (BSM) theories using advanced simulations which can mimic the experimental environment at the colliders as closely as possible. In collider phenomenology jet substructure is a concept that is used frequently to analyse the properties of the jets, characterised as a cluster of hadrons, which is often the end result of particle collisions at the colliders, such as Large Hadron Collider (LHC). A vast literature on jet substructure exists both from the theory and experimental point of view. But, even with the knowledge of Quantum Chromodynamics (QCD), it is hard to cope up with the vastness of the applicability of the subject for a new researcher in this field. In this review, an attempt has been made to bridge the gap between the concept of jet substructure and its application in the collider phenomenology. However, for detailed understanding, one should look at the references.

   hep-phhep-ex0 citations
8. 08*

   Anomalies in the heavy sector

   Giulia Ricciardi🇮🇹

   Heavy flavour physics is well described by the Standard Model with the exception of some measurements which could be pointing to new physics. We briefly review status and prospects of $R(D^{(\ast )})$ and $R(K^{(\ast )})$ anomalies and also address the long standing tension in the $|V_{cb}|$ and $|V_{ub}|$ exclusive/inclusive determinations.

   hep-phhep-exEPJ Web Conf.(2022)·0 citations
9. 09*

   Open-quantum-systems approach to in-medium heavy quarkonium dynamics

   Alexander Rothkopf🇳🇴

   Heavy quarkonium continues to play a central role in the study of nuclear matter under extremes of temperature and density in relativistic heavy-ion collisions. In this talk I report on recent developments in the theoretical description of quarkonium in-medium dynamics using the open-quantum systems approach. Not only does it provide a clear interpretation of the imaginary part of the complex heavy-quark potential but also reveals that a subtle interplay between screening and wavefunction decoherence is responsible for the melting of heavy quarkonium states.

   hep-phnucl-thJ.Phys.Conf.Ser.(2023)·0 citations
10. 10*

    $B\to K^{(\ast )}\nu \bar{\nu }$ in covariant confined quark model

    Aidos Issadykov🇷🇺 · Mikhail A. Ivanov🇷🇺

    We study the $B\to K^{(\ast )}\nu \bar{\nu }$ decays within the Standard Model (SM) by using the relevant transition form factors obtained from the covariant confined quark model (CCQM) developed by us. The $B\to K$ and $B\to K^{\ast }$ transition form factors are calculated in the full kinematic $q^2$ range. The branching fractions are then calculated. It is shown that our results are in an agreement with those obtained in other theoretical approaches. Currently, the Babar and Belle collaborations provide us by the upper limits at 90\% confidence limit. The obtained bounds are roughly an order of magnitude larger than the SM predictions. This should stimulate experimental collaborations to set up experiments that allow one to obtain more accurate branching values, which is quite achievable on the updated LHCb and Belle machines. If the discrepancies between theory and experiment are confirmed, this will open up opportunities for constructing models with new particles and interactions leading to an extension of the SM.

    hep-phMod.Phys.Lett.A(2023)·5 citations
11. 11*

    Higgs decay to charmonia and the charm-quark Yukawa coupling

    Tao Han🇺🇸 · Adam K. Leibovich🇺🇸 · Yang Ma🇺🇸 · Xiao-Ze Tan🇺🇸

    After the great triumph of the Higgs discovery in 2012, the next target at the energy frontier will be to study the Higgs properties and to search for the next scale beyond the SM. Experimentally, the $H\to c\bar{c}$ channel would be extremely difficult to dig out because of both the weak Yukawa coupling and the daunting SM di-jet background. We propose to test the charm-quark Yukawa coupling at the LHC and future hadron colliders with the Higgs boson decay to $J/\psi$ via the charm-quark fragmentation. Using the non-relativistic quantum chromodynamics (NRQCD), we study the charmonia production via the Higgs boson decay channel $H\to c\bar{c}+J/\psi$(or ${\eta }_c$), where both the color-singlet and color-octet contributions are considered. Our result opens another door to improve determinations at the LHC of the Higgs Yukawa couplings: the final state from this decay mode is quite distinctive with $J/\psi \to e^{+}{e}^{-},{\mu }^{+}{\mu }^{-}$ and the branching fraction is enhanced by the charm-quark fragmentation mechanism.

    hep-phhep-exPoS(2022)·1 citation
12. 12*

    Mono-X signal and two component dark matter: new distinction criteria

    Subhaditya Bhattacharya (IIT Guwahati)🇮🇳 · Purusottam Ghosh (IACS)🇮🇳 · Jayita Lahiri (IIT Guwahati)🇮🇳 · Biswarup Mukhopadhyaya (IISER Kolkata)🇮🇳

    The identification and isolation of two WIMP dark matter (DM) components at colliders is of wide interest on the one hand but extremely challenging on the other, especially when the dominant signal of both DM components is of the mono-X type ($X=\gamma ,Z,H$). After emphasizing that an $e^{+}{e}^{-}$ collider is more suitable for this goal, we first identify the theoretical principles that govern the occurrence of two peaks in missing energy (ME) distribution, in a double-DM scenario. We then identify a variable that rather spectacularly elicits the double-peaking behaviour, namely, the plot of bin-wise statistical significance ($S/\sqrt{B}$) against ME. Using Gaussian fits of the histograms, we apply a set of criteria developed by us, to illustrate the above points numerically for suitable benchmarks.

    hep-phPRD(2023)·29 citations
13. 13*

    Effects of Non-Vanishing Net Charge in Balance Functions

    Claude Pruneau🇺🇸 · Victor Gonzalez🇺🇸 · Brian Hanley🇺🇸 · Ana Marin🇩🇪 · Sumit Basu🇸🇪

    We investigate the impact of non-vanishing net-charge in collision systems on measurements of balance functions and their integrals. We show that the nominal balance function definition yields integrals that deviate from unity because of the non-vanishing net-charge. However, the integral of unified balance functions is shown to appropriately converge to unity when measured in a sufficiently wide experimental acceptance. We furthermore explore the rate of convergence of unified balance functions integrals and study distortions imparted on the shape of balance functions when measurements are carried out in limited transverse momentum ($p_{\mathrm{T}}$) and rapidity ($y$) acceptances, such as those featured by experiments at the Large Hadron Collider or the Relativistic Heavy Ion Collider. We show that the shape and integral of unified balance functions may be strongly biased by reductions in the rapidity and transverse momentum acceptances of existing experiments.

    hep-phnucl-exPRC(2023)·7 citations
14. 14*

    Seebeck and Nernst coefficients of a magnetized hot QCD medium with number conserving kernel

    Salman Ahamad Khan🇮🇳 · Binoy Krishna Patra🇮🇳

    We have studied the thermoelectric response of a hot and magnetized QCD medium created in the noncentral events at heavy-ion collider experiments. The collisional aspects of the medium have been embedded in the relativistic Boltzmann transport equation (RBTE) using Bhatnagar-Gross-Krook (BGK) collision integral, which insures the particle number conservation, unlike the commonly used relaxation time approximation (RTA). We have incorporated the thermal medium effects in the guise of a quasiparticle model, where the interaction among the partons is embodied in the medium dependent mass of the quark, which has been evaluated using the framework of the perturbative thermal QCD with a magnetic field in the background. In the absence of $B$, the Seebeck coefficient for individual quark flavors gets slightly reduced in the BGK term in comparison to naive RTA, while it gets enhanced for the composite partonic medium. In the presence of strong magnetic field ($B$), the BGK term enhances the Seebeck coefficient for the individual flavors as well as that for medium. The medium Seebeck coefficient rises with the strength of quark chemical potential ($\mu$) in the absence as well as that in the strong $B$. We observe chirality dependence in the Seebeck and Nernst coefficients in the weak magnetic field as the degeneracy in the masses of left- and right-handed chiral modes gets lifted in the weak $B$. Seebeck coefficient is larger for left-handed modes contrary to the Nernst coefficient which is higher for the right-handed modes. Seebeck coefficient is almost similar in the weak field for both the collision term, while Nernst coefficient gets reduced (enhanced) for $L$ ($R$) modes considerably in the BGK collision term.

    hep-phnucl-thPRD(2023)·7 citations
15. 15*

    Investigation of the tetraquark states $Qq\bar{Q}\bar{q}$ in the improved chromomagnetic interaction model

    Tao Guo🇨🇳 · Jianing Li🇨🇳 · Jiaxing Zhao🇫🇷 · Lianyi He🇨🇳

    In the framework of the improved chromomagnetic interaction model, we complete a systematic study of the $S$-wave tetraquark states $Qq\bar{Q}\bar{q}$ ($Q=c,b$, and $q=u,d,s$) with different quantum numbers, $J^{PC}=0^{+(+)}$, $1^{+(\pm )}$, and $2^{+(+)}$. The mass spectra of tetraquark states are predicted and the possible decay channels are analyzed by considering both the angular momentum and $\mathcal{C}$-parity conservation. The recently observed hidden-charm tetraquark states with strangeness, such as $Z_{cs}(3985{)}^{-}$, $X(3960)$, and $Z_{cs}(4220{)}^{+}$, can be well explained in our model. Besides, based on the wave function of each tetraquark state, we find that the low-lying states of each $Qq\bar{Q}\bar{q}$ configuration have a large overlap to the $Q\bar{Q}$ and $q\bar{q}$ meson basis, instead of $Q\bar{q}$ and $q\bar{Q}$ meson basis. This indicates one can search these tetraquark states in future experiments via the channel of $Q\bar{Q}$ and $q\bar{q}$ mesons.

    hep-phhep-exCPC(2023)·15 citations
16. 16*

    Study on muon MDM and lepton EDM in BLMSSM via the mass insertion approximation

    Xi Wang · Shu-Min Zhao🇨🇳 · Xin-Xin Long🇨🇳 · Yi-Tong Wang · Tong-Tong Wang · Hai-Bin Zhang · Tai-Fu Feng🇨🇳 · Rong-Xiang Zhang

    In the framework of the MSSM extension with local gauged baryon and lepton numbers (BLMSSM), we calculate the muon anomalous magnetic dipole moment (MDM) and lepton $(e,\mu ,\tau )$ electric dipole moment (EDM), and discuss how the muon MDM and lepton EDM depend on the parameters within the mass insertion approximation. Among many parameters, $\tan \beta$,~$g_L$,~$m_L$ and ${\mu }_H$ are more sensitive parameters for $a_{\mu }^{BL}$. Considering the experimental limitations, our best numerical result of $a_{\mu }^{BL}$ is around $2.5\times 10^{-9}$, which can well compensate the departure between the experiment data and Standard Model (SM) prediction. The CP violating phases in BLMSSM are more than those in the MSSM, including new parameters ${\theta }_{{\mu }_L}$ and ${\theta }_L$. They can give large contributions, which play an important role in exploring the source of CP violation and probing new physics beyond SM.

    hep-phJ.Phys.G(2024)·7 citations
17. 17*

    Semi-inclusive deeply inelastic neutrino and antineutrino nucleus scattering

    X. Yang🇨🇳 · W. Yang🇨🇳

    The (anti)neutrino nucleus scattering plays a very important role in probing the hadronic structure as well as the electroweak phenomenologies. To this end, we calculate the jet production semi-inclusive deeply inelastic (anti)neutrino nucleus scattering process. The initial (anti)neutrino is assumed to be scattered off by a target particle with spin 1. Due to the limitation of the factorization theorem, calculations are carried out in the quantum chromodynamics parton model framework up to tree level twist-3. We consider both the neutral current and the charged current processes and write them into a unified form due to the similar interaction forms. Considering the angular modulations and polarizations of the cross section, we calculate the complete azimuthal asymmetries. We also calculate the intrinsic asymmetries which reveal the imbalance in the distribution of the intrinsic transverse momentum of the quark. We find that these asymmetries can be expressed in terms of the transverse momentum-dependent parton distribution functions (TMD PDFs) and the electroweak couplings. With the determined couplings, these asymmetries can be used to extract the TMD PDFs and further to study the hadronic structures.

    hep-phPRD(2023)·6 citations
18. 18*

    Charged lepton flavor violation searches in the charmonium system

    Qiang Li🇨🇳

    An invited research highlight article on Charged lepton flavor violation searches in the charmonium system.

    hep-phSCPMA(2023)·1 citation
19. 19*

    Possible solution of the puzzle for the branching ratio and $CP$ violation in $B\to \pi \pi$ decays with a modified perturbative QCD approach

    Sheng Lü🇨🇳 · Mao-Zhi Yang🇨🇳

    We study $B\to \pi \pi$ decay with a modified perturbative QCD approach. The branching ratios and $CP$ violation are calculated with the transverse momenta of partons considered. Sudakov factor associated with each meson is included to suppress soft contribution in QCD. With the wave function of $B$ meson obtained in QCD-inspired relativistic potential model being used, the suppression of Sudakov factor to the soft contribution is not effective enough. Soft scale cutoff and soft form factors of $B\pi$ transition and $\pi \pi$ production have to be introduced. The main next-to-leading-order contributions of vertex correction, the quark-loop and magnetic penguin are included. To solve the long-standing puzzle in $B\to \pi \pi$ decay, that is the theoretical prediction of the branching ratio of $B^0\to {\pi }^0{\pi }^0$ being seriously smaller than experimental data, color-octet matrix element which is of long-distance dynamics is introduced. With parameters taken with reasonable values, all the branching ratios and $CP$ violation are well consistent with experimental data.

    hep-phhep-exPRD(2023)·8 citations
20. 20*

    $\eta$ meson in strange magnetized matter

    Shivanshi Tiwari · Rajesh Kumar🇺🇸 · Manisha Kumari · Arvind Kumar🇮🇳

    The in-medium properties of $\eta$ mesons are studied in hot and dense isospin asymmetric strange magnetized matter using the chiral SU(3) hadronic mean-field model. The scalar and vector density of baryons are expressed in terms of thermal distribution functions at finite temperature and magnetic field and have dependence on the scalar fields $\sigma$, $\zeta$, and $\delta$ through the effective mass of baryons and the dependence on the vector fields $\omega ,\rho$, and $\varphi$ through the effective chemical potential. The properties of $\eta$ mesons get modified in a hot and dense magnetized environment through the medium-modified nucleons and hyperons. The negative mass shift obtained gives rise to optical potential, which is attractive in the medium and suggests a possibility of $\eta$-mesic bound states formation. The addition of hyperons in the medium enhances the attractive interactions and causes an increased negative mass shift for $\eta$ mesons.

    hep-phnucl-thEur.Phys.J.Plus(2024)·2 citations
21. 21*

    Proton quark distributions from a light-front Faddeev-Bethe-Salpeter approach

    Emanuel Ydrefors🇨🇳 · Tobias Frederico🇧🇷

    The projection onto the Light-Front of a Minkowski space Faddeev-Bethe-Salpeter equation model truncated at the valence level is applied to study the proton structure with constituent quarks. The dynamics of the model has built-in: (i) a bound diquark brought by a contact interaction, and (ii) the separation by \Lambda_QCD of the infrared and ultraviolet interaction regions. The model parameters are fine tuned to reproduce the proton Dirac electromagnetic form factor and mass. From that, the non-polarized longitudinal and transverse momentum distributions were computed. The results for the evolved non-polarized valence parton distributions suggest that: (i) the explicit consideration of the spin degree of freedom of both quark and diquark seems not relevant to it, and (ii) the comparison with the global fit from the NNPDF4.0 calls for higher Fock components of the wave function beyond the valence one.

    hep-phPLB(2023)·5 citations
22. 22*

    Anomalous dimension of transverse momentum broadening in planar $\mathcal{N}=4$ SYM

    Paul Caucal🇫🇷

    The typical transverse momentum $Q_s(t)$ (or "saturation" momentum) acquired by a hard particle propagating through a $\mathcal{N}=4$ SYM plasma increases over time like $t^{\gamma }$, with an anomalous exponent $\gamma >1/2$ characteristic of super-diffusion. This anomalous exponent is a function of the 't Hooft coupling $\lambda =g^2{N}_c$. Recently, a method has been proposed to systematically compute the perturbative series of $\gamma (\lambda )$ at weak coupling. This method relies on the traveling wave interpretation of the time evolution of $Q_s(t)$ and on the dominance of soft-collinear radiative corrections at large times. In this paper, we compute $\gamma (\lambda )$ up to $\mathcal{O}({\lambda }^2)$ using the double logarithmic behaviour of the BFKL equation in planar $\mathcal{N}=4$ SYM at three loops. This calculation allows us to discuss the transition towards the strong coupling regime where AdS/CFT calculations predict $\gamma \to 1$.

    hep-phhep-thnucl-thEPJ Web Conf.(2022)·0 citations
23. 23*

    Data-based determination of the isospin-limit light-quark-connected contribution to the anomalous magnetic moment of the muon

    Diogo Boito🇧🇷 · Maarten Golterman🇺🇸 · Kim Maltman🇨🇦 · Santiago Peris🇪🇸

    We describe how recent determinations of exclusive-mode contributions to $a_{\mu }^{\mathrm{LO},\mathrm{HVP}}$, the leading-order hadronic vacuum polarization contribution to the anomalous magnetic moment of the muon, can be used to provide, up to small electromagnetic (EM) corrections accessible from the lattice, a data-based dispersive determination of $a_{\mu }^{\mathrm{lqc};\mathrm{IL}}$, the isospin-limit, light-quark-connected contribution to $a_{\mu }^{\mathrm{LO},\mathrm{HVP}}$. Such a determination is of interest in view of the existence of a number of lattice results for this quantity, emerging evidence for a tension between lattice and dispersive determinations of $a_{\mu }^{\mathrm{LO},\mathrm{HVP}}$, and the desire to clarify the source of this tension. Taking as input for the small EM correction that must be applied to the purely data-driven dispersive determination the result $-0.93(58)\times 10^{-10}$ obtained in a recent BMW lattice study, we find $a_{\mu }^{\mathrm{lqc};\mathrm{IL}}$ to be $635.0(2.7)\times 10^{-10}$ if the results of Keshavarzi, Nomura and Teubner are used for the exclusive-mode contributions and $638.4(4.1)\times 10^{-10}$ if instead those of Davier, Höcker, Malaescu and Zhang are used.

    hep-phhep-latPRD(2023)·19 citations
24. 24*

    Impact of Lattice Strangeness Asymmetry Data in the CTEQ-TEA Global Analysis

    Tie-Jiun Hou🇨🇳 · Huey-Wen Lin🇺🇸 · Mengshi Yan🇨🇳 · C.-P. Yuan🇺🇸

    We study the impact of lattice data on the determination of the strangeness asymmetry distribution $s_{-}(x)\equiv s(x)-\bar{s}(x)$ in the general CTEQ-TEA global analysis of parton distribution functions (PDFs) of the proton. Firstly, we find that allowing a nonvanishing $s_{-}(x)$, at the initial $Q_0=1.3$~GeV scale, in a global PDF analysis leads to a CT18As fit with similar quality to CT18A. Secondly, including the lattice data in the CT18As\_Lat fit greatly reduces the $s_{-}$-PDF error band size in the large-$x$ region. To further reduce its error would require more precise lattice data, extended to smaller $x$ values. We take ATLAS 7 TeV $W$ and $Z$ production data, SIDIS di-muon production data, $F_3$ structure function data, E866 NuSea data, and E906 SeaQuest data as examples to illustrate the implication of CT18As and CT18As\_Lat fits. The parametrization dependence for PDF ratio $(s+\bar{s})/(\bar{u}+\bar{d})(x)$ is analyzed with CT18As2 and CT18As2\_Lat fits as results.

    hep-phhep-latPRD(2023)·30 citations
25. 25*

    Off-shell generalized parton distributions and form factors of the pion

    Wojciech Broniowski🇵🇱 · Vanamali Shastry🇵🇱 · Enrique Ruiz Arriola🇪🇸

    Off-shell effects in generalized parton distributions (GPDs) of the pion, appearing, e.g., in the Sullivan process, are considered. Due to the lack of crossing symmetry, the moments of GPDs involve also odd powers of the skewness (longitudinal momentum transfer) parameter, which results in emergence of new off-shell form factors. With current-algebra techniques, we derive exact relations between the four off-shell gravitational form factors of the pion, in analogy to the electromagnetic case. Our results place stringent constraints on the off-shell GPDs of the pion. We provide an explicit realization in terms of a chiral quark model, where we show that the off-shell effects in GPDs are potentially significant in modeling physical processes and should not be neglected.

    hep-phhep-thPLB(2023)·19 citations
26. 26*

    Equation of state for strange quark matter: Linking the Nambu--Jona-Lasinio model to perturbative QCD

    Marcus Benghi Pinto🇧🇷

    Neutron star constraints and {\it ab initio} pQCD evaluations require the EoS representing cold quark matter to be stiff at intermediate baryonic densities and soft at high-$n_B$. Here, I suggest that the three flavor NJL model with a density dependent repulsive coupling, $G_V(\mu )$, can generate an EoS which interpolates between these two regimes. Such an interpolation requires repulsion to start decreasing with the chemical potential just after chiral transition takes place. The conjecture behind this mechanism is that repulsion should be necessary only as long as the quark condensates, which dress the effective masses, have non-vanishing values. This assumption guarantees that an initially hard EoS suffers a conspicuous change of slope at $\mathcal{E}\simeq 0.7\mathrm{GeVf}{\mathrm{m}}^{-3}$ converging to the pQCD results at higher energy densities. Then, the speed of sound naturally reaches a non-conformal maximum at $n_B=3.23n_0=0.52{\mathrm{fm}}^{-3}$ while the trace anomaly remains positive for all densities, in agreement with recent investigations. These non-trivial results {\it cannot} be simultaneously obtained when $G_V$ vanishes or has a fixed value. Therefore, the simple model proposed here is able to link the (non-perturbative) region of intermediate densities to the region where pQCD becomes reliable.

    hep-phnucl-thPRC(2023)·10 citations
27. 27*

    Inverse magnetic catalysis and size-dependent effects on the chiral symmetry restoration

    Luciano M. Abreu🇧🇷 · Emerson B. S. Corrêa🇧🇷 · Elenilson S. Nery🇧🇷

    We investigate the combined finite-size and thermo-magnetic effects on the properties of the quark matter, in the context of the two-flavored Nambu--Jona-Lasinio model. In particular, by using the mean-field approximation and the Schwinger proper time method in a toroidal topology with periodic or antiperiodic conditions, we evaluate the chiral phase transition, the constituent quark mass and the thermal and spatial susceptibilities under the change of the size, temperature and strength of external magnetic field. To take into account the inverse magnetic catalysis phenomenon, we make use of a recently proposed magnetized coupling constant. The findings suggest that the observables are strongly affected by the variation of the variables and also by the periodicity of the boundary conditions, with the final outcomes depending on the balance of these competing phenomena.

    hep-phEPJA(2023)·8 citations
28. 28*

    Probing a 96 GeV Higgs Boson in the Di-Photon Channel at the LHC

    Rachid Benbrik (1)🇲🇦 · Mohammed Boukidi (1)🇲🇦 · Stefano Moretti (2) (3)🇬🇧 · Souad Semlali (2) ((1) Polydisciplinary Faculty, Laboratory of Fundamental and Applied Physics, Cadi Ayyad University, Sidi Bouzid, Safi, Morocco, (2) School of Physics and Astronomy, University of Southampton, United Kingdom, (3) Department of Physics and Astronomy, Uppsala University, Uppsala, Sweden)🇬🇧

    Recently the CMS collaboration reported a $\sim 3\sigma$ local excess in the di-photon spectrum at 96 GeV. The same mass range concurs with a $\sim 2\sigma$ local excess in the $b\bar{b}$ invariant mass spectrum in four-jet events collected at LEP. In this contribution we show that at 1$\sigma$ level the 2HDM type-III can perfectly fit both excesses simultaneously, while satisfying all experimental and theoretical constraints.

    hep-phPoS(2022)·9 citations
29. 29*

    Strongly Interacting Dark Matter from $Sp(4)$ Gauge Theory

    Fabian Zierler🇦🇹 · Suchita Kulkarni🇦🇹 · Axel Maas🇦🇹 · Seán Mee🇦🇹 · Marco Nikolic🇦🇹 · Josef Pradler🇦🇹

    The stable hadronic bound states in a hidden new non-Abelian gauge sector provide interesting candidates for strongly-interacting Dark Matter (DM). A particular example are theories in which DM is made up of dark pions which set the DM relic abundance through self-annihilation. One of the simplest realizations is $Sp(4{)}_c$ gauge theory with two Dirac fermions. We discuss its mesonic multiplets for degenerate and non-degenerate fermions, construct a low-energy effective theory and present lattice results for the pseudoscalar mesons and vector mesons.

    hep-phhep-latEPJ Web Conf.(2022)·15 citations
30. 30*

    Spectrum of colour sextet scalars in realistic SO(10) GUT

    Ketan M. Patel🇮🇳 · Saurabh K. Shukla🇮🇳

    Incorporation of the standard model Yukawa interactions in a grand unified theory (GUT) often predicts varieties of new scalars that couple to the fermions and lead to some novel observational effects. We assess such a possibility for the colour sextet diquark scalars within the realistic renormalizable models based on $SO(10)$ GUT. The spectrum consists of five sextets: $\Sigma \sim (6,1,-\frac{2}{3})$, $S\sim (6,1,\frac{1}{3})$, $\overline{S}\sim (\overline{6},1,-\frac{1}{3})$, $\mathcal{S}\sim (6,1,\frac{4}{3})$ and $\mathbb{S}\sim (\overline{6},3,-\frac{1}{3})$. Computing explicitly their couplings with the quarks, we evaluate their contributions to the neutral meson-antimeson mixing and baryon number-violating processes like neutron-antineutron oscillation. The latter arises because of a $B-L$ violating trilinear coupling between the sextets which also contributes to some of the quartic couplings and perturbativity of the same leads to strong limits on the sextet masses. Using the values of the $B-L$ breaking scale and Yukawa couplings permitted in the realistic models, we derive constraints on the masses of these scalars. It is found that $\Sigma$ along with any of the remaining sextets cannot be lighter than the $B-L$ breaking scale, simultaneously. In the realm of realistic models, this implies no observable $n$-$\bar{n}$ oscillation in near future experiments. We also point out a possibility in which sub-GUT scale $\Sigma$ and a pair of $S$, allowed by the other constraints, can viably produce the observed baryon asymmetry of the universe.

    hep-phPRD(2023)·7 citations
31. 31*

    Anomalous magnetohydrodynamics with temperature-dependent electric conductivity and application to the global polarization

    Hao-Hao Peng🇨🇳 · Sihao Wu🇨🇳 · Ren-jie Wang🇨🇳 · Duan She🇨🇳 · Shi Pu🇨🇳

    We have derived the solutions of the relativistic anomalous magnetohydrodynamics with longitudinal Bjorken boost invariance and transverse electromagnetic fields in the presence of temperature or energy density dependent electric conductivity. We consider the equations of states in a high temperature limit or in a high chiral chemical potential limit. We obtain both perturbative analytic solutions up to the order of \hbar and numerical solutions in our configurations of initial electromagnetic fields and Bjorken flow velocity. Our results show that the temperature or energy density dependent electric conductivity plays an important role to the decaying of the energy density and electromagnetic fields. We also implement our results to the splitting of global polarization for \Lambda and \bar{\Lambda} hyperons induced by the magnetic fields. Our results for the splitting of global polarization disagree with the experimental data in low energy collisions, which implies that the contribution from gradient of chemical potential may dominate in the low energy collisions.

    hep-phnucl-thPRD(2023)·23 citations
32. 32*

    Identifying light charged Higgs boson in the $\mu \nu$ channel in 2HDM Type-III

    Rachid Benbrik (1)🇲🇦 · Mohammed Boukidi (1) ((1) Polydisciplinary Faculty, Laboratory of Fundamental and Applied Physics, Cadi Ayyad University, Sidi Bouzid, Safi, Morocco)🇲🇦

    In this contribution, we discuss the light charged Higgs boson production via $pp\to \bar{t}b{H}^{\pm }$ at the Large Hadron Collider (LHC) in the Two-Higgs Doublet Model (2HDM) Type-III. We explore the prospect of looking the aforementioned Higgs boson production channel followed by $H^{\pm }\mu \nu$ signal. The latter has the potential to be overwhelmingly stronger than $H^{\pm }\tau \nu$ and $H^{\pm }c\bar{s}$ signals in Type-III. We show that in both scenarios standard and inverted hierarchy and after including several theoretical and experimental constraints, the production process $pp\to \bar{t}b{H}^{\pm }$ followed by $H^{\pm }\to \mu \nu$ could represent the most promising experimental option to search for light charged Higgs boson at the LHC.

    hep-phPoS(2023)·0 citations
33. 33*

    $|V_{cb}|$, LFU and $SU(3{)}_F$ symmetry breaking in $B_{(s)}\to D_{(s)}^{(\ast )}\ell {\nu }_{\ell }$ decays using Lattice QCD and Unitarity

    Guido Martinelli🇮🇹 · Manuel Naviglio🇮🇹 · Silvano Simula🇮🇹 · Ludovico Vittorio🇫🇷

    We present an application of the unitarity-based dispersion matrix (DM) approach to the extraction of the CKM matrix element $|V_{cb}|$ from the experimental data on the exclusive semileptonic $B_{(s)}\to D_{(s)}^{(\ast )}\ell {\nu }_{\ell }$ decays. The DM method allows to achieve a non-perturbative, model-independent determination of the momentum dependence of the semileptonic form factors. Starting from lattice results available at large values of the 4-momentum transfer and implementing non-perturbative unitarity bound, the behaviour of the form factors in their whole kinematical range is obtained without introducing any explicit parameterization of their momentum dependence. We consider the four exclusive semileptonic $B_{(s)}\to D_{(s)}^{(\ast )}\ell {\nu }_{\ell }$ decays and extract $|V_{cb}|$ from the experimental data for each transition. The average over the four channels is $|V_{cb}|=(41.2\pm 0.8)\cdot 10^{-3}$, which is compatible with the latest inclusive determination at $1\sigma$ level. We address also the issue of Lepton Flavour Universality by computing pure theoretical estimates of the $\tau /\ell$ ratios of the branching fractions for each channel, where $\ell$ is a light lepton. In the case of a light spectator quark we obtain $R(D^{\ast })=0.275(8)$ and $R(D)=0.296(8)$, which are compatible with the corresponding experimental values within $1.3\sigma$. In the case of a strange spectator quark we obtain $\text{R}(D_s^{\ast })=0.2497(60)$ and $\text{R}(D_s)=0.298(5)$. The different values for $R(D_s^{\ast })$ and $R(D^{\ast })$ may reflect $SU(3{)}_F$ symmetry breaking effects, which seem to be present in some of the lattice form factors, especially at large values of the recoil.

    hep-phhep-exhep-latPoS(2022)·2 citations
34. 34*

    Minimal Leptogenesis in Brane-inspired Cosmology

    Alessandro Di Marco🇮🇹 · Amit Dutta Banik🇮🇳 · Anish Ghoshal🇵🇱 · Gianfranco Pradisi🇮🇹

    We discuss how a post inflationary reheating phase characterized by a nonstandard multiple scalar field cosmology can change the thermal history of the universe, affecting minimal high scale leptogenesis. In particular, we explore a class of models where a set of scalar fields in a brane-inspired dynamical scenario modifies the Boltzmann equations concerning standard leptogenesis. The produced lepton asymmetry, due to the decays of heavy Majorana right-handed neutrinos responsible for generating Standard Model neutrino masses via the type-I seesaw, is affected as well.

    hep-phPRD(2023)·5 citations
35. 35*

    Chiral instabilities & the fate of chirality imbalance in non-Abelian plasmas

    Sören Schlichting🇩🇪 · Sayantan Sharma🇮🇳

    We present a first principles study of chiral plasma instabilities and axial charge transfer in non-Abelian plasmas with a strong gauge-matter coupling $g^2{N}_f=64$, by performing $3+1$ D real-time classical-statistical lattice simulation with dynamical fermions. We explicitly demonstrate for the first time that -- unlike in an Abelian plasma -- the transfer of chirality from the matter sector to the gauge fields occurs predominantly due to topological sphaleron transitions. We elaborate on the similarities and differences of the axial charge dynamics in cold Abelian $U(1)$ and non-Abelian $SU(2)$ plasmas, and comment on the implications of our findings for the study of anomalous transport phenomena, such as the chiral magnetic effect in QCD matter.

    hep-phhep-latnucl-thPRL(2023)·14 citations
36. 36*

    Hunting light Higgses at the LHC in the context of the 2HDM Type-I

    S. Moretti🇬🇧 · S. Semlali🇬🇧 · C. H. Shepherd-Themistocleous🇬🇧

    We show the reinterpretation of existing searches for exotic decays of the Standard Model (SM)-like Higgs, $H\to aa(hh)$, in various final states, in the framework of the 2-Higgs Doublet Model (2HDM) Type-I. We then explore a new search for such light Higgses, $a$ and $h$, at the Large Hadron Collider (LHC) Run 3 for an integrated luminosity of 300 ${\text{fb}}^{-1}$. After performing a scan over the model parameters, we found that the inverted scenario of Type-I offers a new promising signal in the form of the following cascade decays: $H\to Z^{\ast }a\to Z^{\ast }{Z}^{\ast }h\to b\overline{b}{\mu }^{-}{\mu }^{+}jj$. We investigate then its significance through a full Monte Carlo (MC) simulation down to the detector level.

    hep-phPoS(2022)·2 citations
37. 37*

    Thoughts about the utility of perturbative QCD in the cores of neutron stars

    Aleksi Kurkela🇳🇴

    In this contribution, I discuss the utility that perturbative QCD offers in studying the matter in the cores of neutron stars. I discuss the reasons why perturbative QCD can constrain the equation of state at densities far below the densities where we can perform controlled calculations. I discuss how perturbative QCD can inform nuclear modelling of neutron stars and how it influences equation-of-state inference. And finally, I discuss the implications to the QCD phase diagram and argue that interesting features in the equation of state revealed by the QCD input may be used to argue for the existence of quark-matter cores in most massive neutron stars.

    hep-phastro-ph.HEnucl-thEPJ Web Conf.(2022)·9 citations
38. 38*

    One-loop radiative corrections to photon-pair production in polarized positron-electron annihilation

    S. Bondarenko (1)🇷🇺 · Ya. Dydyshka (2,3)🇷🇺 · L. Kalinovskaya (2)🇷🇺 · A. Kampf (2)🇷🇺 · L. Rumyantsev (2)🇷🇺 · R. Sadykov (2)🇷🇺 · V. Yermolchyk (2,3) ((1) Bogoliubov Laboratory of Theoretical Physics, JINR, 141980 Dubna, Moscow region, Russia, (2) Dzhelepov Laboratory of Nuclear Problems, JINR, 141980 Dubna, Moscow region, Russia, (3) Institute for Nuclear Problems, Belarusian State University, Minsk, 220006 Belarus)🇷🇺

    A theoretical description of photon-pair production in polarized positron-electron annihilation is presented. Complete one-loop electroweak radiative corrections are calculated taking into account the exact dependence on the electron mass. Analytical results are derived with the help of the SANC~system. The relevant contributions to the cross section are calculated analytically using the helicity amplitude approach. The cases of unpolarized and longitudinally polarized fermions in the initial state are investigated. Calculations are realized in the Monte Carlo integrator MCSANCee and generator ReneSANCe which allow one the implementation of any experimental cuts used in the analysis of $e^{+}{e}^{-}$ annihilation data of both low and high energies.

    hep-phPRD(2023)·8 citations
39. 39*

    Millicharged particles from proton bremsstrahlung in the atmosphere

    Mingxuan Du🇨🇳 · Rundong Fang🇨🇳 · Zuowei Liu🇨🇳

    Light millicharged particles can be copiously produced from meson decays in cosmic ray collisions with the atmosphere, leading to detectable signals in large underground neutrino detectors. In this paper we study a new channel for generating atmospheric millicharged particles, the proton bremsstrahlung process. We find that the proton bremsstrahlung process leads to a significantly higher flux of millicharged particles compared to meson decays and, for certain masses, results in a one-order-of-magnitude improvement in the flux. Consequently, Super-K constraints on ${\epsilon }^2$ for sub-GeV MCPs are improved by half order of magnitude. We further note that the study on the proton bremsstrahlung process can be extended to a variety of new physics particle searches in atmospheric collisions and in low energy proton accelerators.

    hep-phastro-ph.COhep-exJHEP(2024)·23 citations
40. 40*

    Axion haloscope signal power from reciprocity

    Jacob Egge🇩🇪

    Axion haloscopes search for dark matter axions from the galactic halo, most commonly by measuring a power excess sourced by the axion effective current density. Constraining axion parameters from detection or lack thereof requires estimating the expected signal power. Often, this is done by studying the response of the haloscope to a known, but different, source current density, for example via a reflection measurement. However, only in the special case when both sources induce the same electromagnetic fields, do the quantities derived from a reflection measurement adequately describe the setup during an axion measurement. While this might be valid for the traditional resonant cavity haloscope, new broadband or open designs like dish antennas or dielectric haloscopes cannot make this assumption. A more general relation between axion- and reflection-induced fields is needed. In this article, we use the Lorentz reciprocity theorem to derive an expression for the axion signal power which instead of the unmeasurable axion-induced fields depends on the measurable reflection-induced fields. This entirely circumvents the need to know the response of the haloscope to the unknown axion source. It applies to a wide variety of haloscopes including resonant cavities, dielectric haloscopes, and broadband dish antennas.

    hep-phastro-ph.COhep-exJCAP(2023)·16 citations
41. 41*

    Complete study of four top quark production at the LHC in the SMEFT

    Hesham El Faham🇧🇪

    We present a study of four top quark production at the LHC in the Standard Model Effective Field Theory (SMEFT). The analysis is performed at the tree-level, including all terms from the mixed QCD-EW-coupling cross-section expansion and all the relevant dimension-six SMEFT operators. We find several cases in which formally subleading terms give rise to significant contributions. Moreover, we obtain limits on the SMEFT Wilson coefficients (WCs), including different collider setups, FCC-hh and HL-LHC, using a simplified chi-square fit. Through the latter, we also assessed the importance of including differential information in the fit.

    hep-phPoS·0 citations
42. 42*

    Enhancement of the screening effect in semiconductor detectors in the presence of the neutrino magnetic moment

    Yu-Feng Li🇨🇳 · Shuo-yu Xia🇨🇳

    The theoretical framework of the neutrino electron excitation at low energies including the screening effect in semiconductor detectors is developed for the first time, both in the Standard Model and in the presence of the neutrino magnetic moment. We explore the contribution of the screening effect of semiconductors to the neutrino electron excitation based on the linear response theory and calculate the corresponding numerical results. We show that excitation rates from the neutrino magnetic moment are dramatically enhanced {by} the screening effect and the sensitivity can be significantly improved to the level of $10^{-13}{\mu }_{\mathrm{B}}$, much better than the current {laboratory and astrophysical} limits.

    hep-phhep-exJHEP(2023)·1 citation
43. 43*

    Hilbert Series and Operator Counting on the Higgs Effective Field Theory

    Hao Sun🇨🇳 · Yi-Ning Wang🇨🇳 · Jiang-Hao Yu🇨🇳

    We present a systematic procedure for determining the Hilbert series that counts the number of independent operators in the Higgs effective field theory. After removing the redundancies from equation-of-motion and integration-by-part, we provide an algorithm of treating the redundancy from the operators involving in spurion fields parametrizing the custodial symmetry breaking. Furthermore, we utilize the outer automorphism of the Lorentz and internal symmetries to separate operators with different CP properties. With these new implements, the Hilbert series up to chiral dimension 10 are obtained, and CP-even and CP-odd operators can be further divided. Extensions to all orders are straightforward.

    hep-phhep-th35 citations
44. 44*

    Radiative modes $K^{+}\to {\pi }^{+}{\gamma }^{\ast }{\gamma }^{(\ast )}$ and the $K^{+}\to {\pi }^{+}4e$ decay

    Tomáš Husek (Lund U.)🇸🇪

    We discuss radiative transitions of a charged kaon to a pion and two photons. In particular, we have a closer look at radiative corrections for the $K^{+}\to {\pi }^{+}{\ell }^{+}{\ell }^{-}$ decays and present the branching ratio of the $K^{+}\to {\pi }^{+}{e}^{+}{e}^{-}{e}^{+}{e}^{-}$ process calculated for the first time at leading order in the Standard Model.

    hep-phJ.Phys.Conf.Ser.(2023)·1 citation
45. 45*

    Massive Dark Photons as Hot Dark Matter

    Salah Eddine Ennadifi🇲🇦

    Motivated by the growing interest in the existence of new massive gauge bosons, we suggest that massive dark photons A0 can be a consequence of a broken new abelian symmetry U(1)'X. Such a dark symmetry U(1)'D is afterwards supposed to be associated with the conservation of the weak number W belonging to the Weakling Interacting Slim Particles U(1)'W, being a strong candidate for Hot Dark Matter. The latters correspond then to light dark photons m'A inf keV from a weak symmetry breaking scale sup 10keV.

    hep-phActa Phys.Polon.B(2022)·2 citations
46. 46*

    QCD Equation of State of Dense Nuclear Matter from a Bayesian Analysis of Heavy-Ion Collision Data

    Manjunath Omana Kuttan🇩🇪 · Jan Steinheimer🇩🇪 · Kai Zhou🇩🇪 · Horst Stoecker🇩🇪

    Bayesian methods are used to constrain the density dependence of the QCD Equation of State (EoS) for dense nuclear matter using the data of mean transverse kinetic energy and elliptic flow of protons from heavy ion collisions (HIC), in the beam energy range $\sqrt{s_{\mathrm{NN}}}=2-10GeV$. The analysis yields tight constraints on the density dependent EoS up to 4 times the nuclear saturation density. The extracted EoS yields good agreement with other observables measured in HIC experiments and constraints from astrophysical observations both of which were not used in the inference. The sensitivity of inference to the choice of observables is also discussed.

    hep-phhep-exnucl-exnucl-thPRL(2023)·65 citations
47. 47*

    On-shell versus curvature mass parameter fixing schemes in the three flavor quark-meson model with vacuum fluctuations

    Vivek Kumar Tiwari🇮🇳

    The vacuum effective potential and phase diagram for the three (2+1) flavor quark-meson model have been computed and compared in an extended mean-field approximation (e-MFA) where the model parameters are fixed by using different renormalization prescriptions after including quark one-loop vacuum fluctuations. When the vacuum one-loop divergence is regularized in the minimal subtraction scheme and the curvature masses of the scalar and pseudo-scalar mesons are used for fixing the parameters, the setting of the quark-meson model with the vacuum term (QMVT) turns out to be inconsistent as one notes that the curvature masses are defined by the evaluation of self-energy at zero momentum. This work constitutes the first application of the consistent on-shell parameter fixing scheme to the three flavor quark-meson (QM) model. In this setting of the renormalized quark-meson (RQM) model, the physical (pole) masses of the $\pi ,K,\eta$ and ${\eta }^{\prime }$ pseudo-scalar mesons and the scalar $\sigma$ meson,the pion decay constant and kaon decay constant are put into the relation of the running mass parameter and couplings by using the on-shell and the minimal subtraction renormalization schemes. The nonstrange direction normalized vacuum effective potential plots for both the RQM model and QMVT model, are exactly identical for the $m_{\sigma }=$ 658.8 MeV while the nonstrange direction order parameter temperature variations and phase diagrams for both the models RQM and PQMVT are identical when the $m_{\sigma }$ value is smaller by 10 MeV i.e. $m_{\sigma }=$ 648 MeV. This happens because the normalized vacuum effective potential variation in the nonstrange direction is somewhat influenced by its variation in the strange direction.

    hep-phnucl-thPRD(2023)·10 citations
48. 48*

    Neutron stars and phase diagram from a double hard-wall

    Lorenzo Bartolini🇨🇳 · Sven Bjarke Gudnason🇨🇳 · Josef Leutgeb🇦🇹 · Anton Rebhan🇦🇹

    Description of nuclear matter in the core of neutron stars eludes the main tools of investigation of QCD, such as perturbation theory and the lattice formulation of the theory. Recently, the application of the holographic paradigm (both via top-down and bottom-up models) to this task has led to many encouraging results, both qualitatively and quantitatively. We present our approach to the description of neutron star cores, relying on a simple model of the (double) hard-wall type: we discuss results concerning the nature of homogeneous nuclear matter at high density emerging from the model including a quarkyonic phase, the mass-radius relation for neutron stars, as well as the rather stiff equation of state we have found. We show how, despite the very simple model employed, for an appropriate calibration we are able to obtain neutron stars that only slightly fall short of the observational bounds on radius and tidal deformability.

    hep-phhep-thEPJ Web Conf.(2022)·1 citation
49. 49*

    Searches for scalars at LHC and interpretation of the findings

    Anirban Kundu🇮🇳 · Alain Le Yaouanc🇫🇷 · Poulami Mondal🇮🇳 · François Richard🇫🇷

    In view of the future Higgs factories, this work presents the status of scalar searches at the LHC with an emphasis on the H(650) resonance which has been observed in WW, ZZ and h(95)h(125) channels, with a cumulative evidence of about 7 s.d. global significance. Its interpretation in models, restricted to extension of the scalar sector by SU(2) singlets and doublets, is clearly excluded, while its interpretation in models with additional triplets requires an extension with respect to the conventional Georgi-Machacek model. A general picture of these searches is updated, showing that h(95) is also reaching a similar level of evidence while two other candidates, A(400) and h(151), although less prominent, are above the 4 s.d. global evidence.

    hep-phhep-ex17 citations
50. 50*

    Axion from pseudo Goldstone seesaw without Peccei-Quinn symmetry

    Pei-Hong Gu🇨🇳

    It is firmly believed that the axion for solving the strong CP problem must come from the spontaneous breaking of an anomalous Peccei-Quinn global symmetry. Here we show a new possibility that the axion can be induced by a pseudo Goldstone seesaw mechanism although the Peccei-Quinn symmetry is exactly forbidden. Specifically, after the spontaneous breaking of appropriate gauge and discrete symmetries, a heavy pseudo Goldstone coupling to colored fermions is allowed to have a tiny mass mixing with an ultralight pseudo Goldstone. In our scenario, no symmetry breaking is required to happen above the TeV scale. This means rich collider phenomena to explore the origin of axion.

    hep-ph0 citations
51. 51*

    The Rumble in the Meson: a leptoquark versus a $Z^{\prime }$ to fit $b\to s{\mu }^{+}{\mu }^{-}$ anomalies including 2022 LHCb $R_{K^{(\ast )}}$ measurements

    Ben Allanach (CERN, University of Cambridge)🇬🇧 · Joe Davighi (Zurich University)🇨🇭

    We juxtapose global fits of two bottom-up models (an $S_3$ scalar leptoquark model and a $B_3-L_2$ $Z^{\prime }$ model) of \bsll\ anomalies to flavour data in order to quantify statistical preference or lack thereof. The leptoquark model couples directly to left-handed di-muon pairs, whereas the $Z^{\prime }$ model couples to di-muon pairs with a vector-like coupling. $B_s-\overline{B_s}$ mixing is a focus because it is typically expected to disfavour $Z^{\prime }$ explanations. In two-parameter fits to 247 flavour observables, including $B_{s/d}\to {\mu }^{+}{\mu }^{-}$ branching ratios for which we provide an updated combination and LHCb $R_{K^{(\ast )}}$ measurements from December 2022, we show that each model provides a similar improvement in quality-of-fit of $\sqrt{\Delta {\chi }^2}=3.6$ with respect to the Standard Model. The main effect of the $B_s-\overline{B_s}$ mixing constraint in the $Z^{\prime }$ model is to disfavour values of the $s_L-b_L$ mixing angle greater than about $5|V_{cb}|$. This limit is rather loose, meaning that a good fit to data does not require `alignment' in either quark Yukawa matrix. No curtailment of the $s_L-b_L$ mixing angle is evident in the $S_3$ model.

    hep-phJHEP(2023)·30 citations
52. 52*

    Dark matter production via a non-minimal coupling to gravity

    Oleg Lebedev🇫🇮 · Timofey Solomko🇷🇺 · Jong-Hyun Yoon🇫🇷

    We study postinflationary scalar dark matter production via its non-minimal coupling to gravity. During the inflaton oscillation epoch, dark matter is produced resonantly for a sufficiently large non-minimal coupling $\xi \gtrsim 5$. We find that backreaction on the curvature and rescattering effects typically become important for the values of $\xi$ above $30$, which invalidate simple estimates of the production efficiency. At large couplings, the dark matter yield becomes almost independent of $\xi$, signifying approximate quasi-equilibrium in the inflaton-dark matter system. Although the analysis gets complicated by the presence of apparent negative energy in the Jordan frame, this behaviour can be regularized by introducing mild dark matter self-interaction. Using lattice simulations, we delineate parameter space leading to the correct dark matter relic abundance.

    hep-phastro-ph.COgr-qcJCAP(2023)·33 citations
53. 53*

    Stabilizing BFKL via heavy-flavor and NRQCD fragmentation

    Francesco Giovanni Celiberto🇮🇹

    We bring evidence that the recently discovered property of natural stability of the high-energy resummation is directly connected to the fragmentation mechanism of heavy hadrons. As a phenomenological support, we provide predictions for differential distributions sensitive to heavy-hadron tags, calculated at the next-to-leading logarithmic level of the hybrid high-energy/collinear factorization (NLL/NLO), as implemented in the JETHAD multimodular code. We show that the stabilizing mechanism is encoded in gluon channels of both heavy-flavor collinear fragmentation functions extracted from data and the ones evolved from a non-relativistic QCD input.

    hep-phhep-exActa Phys.Polon.Supp.(2023)·29 citations
54. 54*

    Quantum coherence in relativistic transport theory: applications to baryogenesis

    Henri Jukkala🇫🇮

    We derive field-theoretic local quantum transport equations which can describe quantum coherence. Our methods are based on Kadanoff--Baym equations derived in the Schwinger--Keldysh closed time path formalism of non-equilibrium quantum field theory. We focus on spatially homogeneous and isotropic systems and mixing fermions with a time-dependent mass and a weak coupling to a thermal plasma. We introduce a new local approximation (LA) method and use it to derive quantum kinetic equations which can describe coherence and also include effects of the spectral width. The method is based on a local ansatz of the collision term. We also improve the earlier coherent quasiparticle approximation (cQPA) by giving a straightforward derivation of the spectral ansatz, a new way of organizing the gradient expansion, and a transparent way to derive the coherence-gradient resummed collision term. In both methods the transport equations can describe flavor coherence and particle--antiparticle coherence, and the related oscillations, of the mixing fermions. In addition to formulating the local equations we apply them to baryogenesis in the early universe. More specifically, we study the details of CP-asymmetry generation in resonant leptogenesis and the evolution of the axial vector current in electroweak baryogenesis (in a time-dependent analogue). We solve the equations numerically, and perform extensive analysis and compare the results to semiclassical (Boltzmann) equations. The results cover known semiclassical effects. We find that dynamical treatment of local quantum coherence is necessary for an accurate description of CP-asymmetry generation. When these details are known they can then be partially incorporated into simpler (e.g. semiclassical) approaches. However, coherent quantum kinetic equations are needed for accurate results across different scenarios or wide parameter ranges.

    hep-phastro-ph.COhep-thJYU Dissertations 553, University of Jyv\…·4 citations
55. 55*

    Dead-cone searches in heavy-ion collisions using the jet tree

    Leticia Cunqueiro🇮🇹 · Davide Napoletano🇮🇹 · Alba Soto-Ontoso🇨🇭

    We explore the possibility of using the dead cone of heavy quarks as a region of the Lund plane where medium-induced gluon radiation can be isolated and characterised. The filling of the dead cone by medium-induced gluons is expected to be the result of the interplay between the minimum angle of such radiation due to transverse momentum broadening and the dead-cone angle. Since the measurement of a fully corrected Lund plane in heavy-ion collisions is currently challenging, we propose to use jet grooming techniques to identify a particular splitting in the jet tree that is both perturbative and sensitive to the dead-cone effect. To that end, we propose a new jet substructure groomer, dubbed Late-$k_t$, that selects the most collinear splitting in a QCD jet above a certain transverse momentum cutoff $k_{t,\mathrm{cut}}$. The role of $k_{t,\mathrm{cut}}$ is to guarantee perturbative splittings, while selecting the most collinear splitting enhances the sensitivity to mass effects. As a proof of concept, we study the angular distribution of the splitting tagged by Late-$k_t$ both analytically and with Monte Carlo simulations. First, we derive the logarithmic resummation structure in vacuum and demonstrate its capability to distinguish between inclusive and heavy-flavoured jets. Next, we extend the calculation for in-medium jets and show that medium-induced emissions lead to an enhancement of collinear emissions below the dead cone angle. Numerically, we demonstrate an excellent resilience of Late-$k_t$ against uncorrelated thermal background, thus confirming this observable as a potential candidate to unveil medium dynamics around the dead cone regime.

    hep-phhep-exnucl-exnucl-thPRD(2023)·27 citations
56. 56*

    Axion-Like Dark Matter Detection Using Stern-Gerlach Interferometer

    Milad Hajebrahimi🇮🇷 · Hassan Manshouri🇮🇷 · Mohammad Sharifian🇮🇷 · Moslem Zarei🇮🇷

    Quantum sensors based on the superposition of neutral atoms are promising for sensing the nature of dark matter (DM). In this study, we utilize the Stern-Gerlach (SG) interferometer configuration to seek a novel method for the detection of detect axion-like particles (ALPs). Using an SG interferometer, we create a spatial quantum superposition of neutral atoms such as ${}^3$He and ${}^{87}$Rb. It is shown that the interaction of ALPs with this superposition induces a relative phase between superposed quantum components. We use the quantum Boltzmann equation (QBE) to introduce a first-principles analysis that describes the temporal evolution of the sensing system. The QBE approach employs quantum field theory (QFT) to highlight the role of the quantum nature of the interactions with the quantum systems. The resulting exclusion area demonstrates that our scheme allows for the exclusion of a range of ALP mass in the range of $10^{-10}\le m_a\le 10^2\mathrm{eV}$ and ALP-atom coupling constant in the range $10^{-13}\le g_{ae}\le 10^0$.

    hep-phastro-ph.COquant-phEPJC(2023)·11 citations
57. 57*

    Efficient quantum implementation of 2+1 U(1) lattice gauge theories with Gauss law constraints

    Christopher Kane🇺🇸 · Dorota M. Grabowska🇨🇭 · Benjamin Nachman🇺🇸 · Christian W. Bauer🇺🇸

    The study of real-time evolution of lattice quantum field theories using classical computers is known to scale exponentially with the number of lattice sites. Due to a fundamentally different computational strategy, quantum computers hold the promise of allowing for detailed studies of these dynamics from first principles. However, much like with classical computations, it is important that quantum algorithms do not have a cost that scales exponentially with the volume. Recently, it was shown how to break the exponential scaling of a naive implementation of a U(1) gauge theory in two spatial dimensions through an operator redefinition. In this work, we describe modifications to how operators must be sampled in the new operator basis to keep digitization errors small. We compare the precision of the energies and plaquette expectation value between the two operator bases and find they are comparable. Additionally, we provide an explicit circuit construction for the Suzuki-Trotter implementation of the theory using the Walsh function formalism. The gate count scaling is studied as a function of the lattice volume, for both exact circuits and approximate circuits where rotation gates with small arguments have been dropped. We study the errors from finite Suzuki-Trotter time-step, circuit approximation, and quantum noise in a calculation of an explicit observable using IBMQ superconducting qubit hardware. We find the gate count scaling for the approximate circuits can be further reduced by up to a power of the volume without introducing larger errors.

    ↳ quant-phhep-lathep-ph42 citations
58. 58*

    How does dark matter affect compact star properties and high density constraints of strongly interacting matter

    Violetta Sagun🇵🇹 · Edoardo Giangrandi🇵🇹 · Oleksii Ivanytskyi🇵🇱 · Costança Providência🇵🇹 · Tim Dietrich🇩🇪

    We study the impact of asymmetric bosonic dark matter on neutron star properties, including possible changes of tidal deformability, maximum mass, radius, and matter distribution inside the star. The conditions at which dark matter particles tend to condensate in the star's core or create an extended halo are presented. We show that dark matter condensed in a core leads to a decrease of the total gravitational mass and tidal deformability compared to a pure baryonic star, which we will perceive as an effective softening of the equation of state. On the other hand, the presence of a dark matter halo increases those observable quantities. Thus, observational data on compact stars could be affected by accumulated dark matter and, consequently, constraints we put on strongly interacting matter at high densities. To confirm the presence of dark matter in the compact star's interior, and to break the degeneracy between the effect of accumulated dark matter and strongly interacting matter properties at high densities, several astrophysical and GW tests are proposed.

    ↳ astro-ph.HEgr-qchep-phnucl-thEPJ Web Conf.(2022)·15 citations
59. 59*

    Pre-hydrodynamic evolution in large and small systems

    Tiago Nunes da Silva🇧🇷 · David D. Chinellato🇧🇷 · André V. Giannini🇧🇷 · Maurício N. Ferreira🇪🇸 · Gabriel S. Denicol🇧🇷 · Maurício Hippert🇺🇸 · Matthew Luzum🇧🇷 · Jorge Noronha🇺🇸 · Jun Takahashi🇧🇷

    We extend our previous investigation of the effects of pre-hydrodynamic evolution on final-state observables in heavy-ion collisions to smaller systems. We use a state-of-the-art hybrid model for the numerical simulations with optimal parameters obtained from a previous Bayesian study. By studying p-Pb collisions, we find that the effects due to the assumption of a conformal evolution in the pre-hydrodynamical stage are even more important in small systems. We also show that this effect depends on the time duration of the pre-equilibrium stage, which is further enhanced in small systems. Finally, we show that the recent proposal of a free-streaming with subluminal velocity for the pre-equilibrium stage, thus effectively breaking conformal invariance, can alleviate the contamination of final state observables. Our study further reinforces the need for moving beyond conformal approaches in pre-equilibrium dynamics modeling, especially when extracting transport coefficients from hybrid models in the high-precision era of heavy-ion collisions.

    ↳ nucl-thhep-phPRC(2023)·21 citations
60. 60*

    Effect of the $\sigma$-cut potential on the properties of neutron stars with or without a hyperonic core

    N. K. Patra🇮🇳 · B. K. Sharma🇮🇳 · A. Reghunath🇩🇪 · A. K. H. Das · T. K. Jha🇮🇳

    Motivated by the recent observation of high-mass pulsars ($M\simeq 2M_{\odot }$), we employ the $\sigma$-cut potential on the equation of state (EOS) of high-density matter and the properties of neutron stars within the relativistic mean-field (RMF) model using TM1${}^{\ast }$ parameter set. The $\sigma$-cut potential is known to reduce the contributions of the $\sigma$ field, resulting in a stiffer EOS at high densities and hence leading to larger neutron star masses without affecting the properties of nuclear matter at normal saturation density. We also analyzed the effect of the same on pure neutron matter and also on the neutron star matter with and without hyperonic core and compared it with the available theoretical, experimental, and observational data. The corresponding tidal deformability (${\Lambda }_{1.4}$) is also calculated. With the choice of meson-hyperon coupling fixed to hypernuclear potentials, we obtain $\approx 10\%$ increase in mass by employing the $\sigma$-cut potential for $f_s=0.6$. Our results are in good agreement with various experimental constraints and observational data, particularly with the GW170817 data.

    ↳ nucl-thastro-ph.HEgr-qchep-phPRC(2022)·14 citations
61. 61*

    Inverse problems, real-time dynamics and lattice simulations

    Alexander Rothkopf🇳🇴

    The determination of real-time dynamics of strongly coupled quantum fields is a central goal of modern nuclear and particle physics, which requires insight into quantum field theory beyond the weak-coupling approximation. While lattice QCD has provided vital insights into the non-perturbative static properties of quarks and gluons it hides their real-time dynamics behind an ill-posed inverse problem. In this proceeding I will discuss developments in tackling the inverse problem on the lattice and touch upon progress in the direct simualtion of real-time dynamics.

    ↳ hep-lathep-phEPJ Web Conf.(2022)·32 citations
62. 62*

    Magnetic dynamo caused by axions in neutron stars

    Filippo Anzuini🇦🇺 · José A. Pons🇪🇸 · Antonio Gómez-Bañón🇪🇸 · Paul D. Lasky🇦🇺 · Federico Bianchini🇺🇸 · Andrew Melatos🇦🇺

    The coupling between axions and photons modifies Maxwell's equations, introducing a dynamo term in the magnetic induction equation. In neutron stars, for critical values of the axion decay constant and axion mass, the magnetic dynamo mechanism increases the total magnetic energy of the star. We show that this generates substantial internal heating due to enhanced dissipation of crustal electric currents. These mechanisms would lead magnetized neutron stars to increase their magnetic energy and thermal luminosity by several orders of magnitude, in contrast to observations of thermally-emitting neutron stars. To prevent the activation of the dynamo, bounds on the allowed axion parameter space can be derived.

    ↳ astro-ph.HEhep-phPRL(2023)·11 citations
63. 63*

    Interpretable Scientific Discovery with Symbolic Regression: A Review

    Nour Makke🇮🇹 · Sanjay Chawla🇶🇦

    Symbolic regression is emerging as a promising machine learning method for learning succinct underlying interpretable mathematical expressions directly from data. Whereas it has been traditionally tackled with genetic programming, it has recently gained a growing interest in deep learning as a data-driven model discovery method, achieving significant advances in various application domains ranging from fundamental to applied sciences. This survey presents a structured and comprehensive overview of symbolic regression methods and discusses their strengths and limitations.

    ↳ cs.LGcs.AIhep-phArtif.Intell.Rev.(2024)·19 citations
64. 64*

    Probing new physics at the LUXE experiment

    Shan Huang (for the LUXE Collaboration)🇮🇱

    The proposed LUXE experiment (Laser und XFEL Experiment) at DESY Hamburg, using the electron beam from the European XFEL, aims to probe QED in the non-perturbative regime created in collisions between high-intensity laser pulses and high-energy electron or photon beams. This setup also provides a unique opportunity to probe physics beyond the standard model. In this proceedings, we show that by leveraging the large photon flux generated at LUXE, one can probe axion-like-particles (ALPs) up to a mass of 350 MeV and with a photon coupling of $3\times {10}^{-6}{\mathrm{GeV}}^{-1}$. This reach is comparable to the background-free projection from NA62. In addition, we will discuss other probes of new physics such as ALPs-electron coupling.

    ↳ hep-exhep-phPoS·3 citations
65. 65*

    The Future of US Particle Physics -- The Snowmass 2021 Energy Frontier Report

    Meenakshi Narain · Laura Reina · Alessandro Tricoli · Michael Begel · Alberto Belloni · Tulika Bose · Antonio Boveia · Sally Dawson · Caterina Doglioni · Ayres Freitas · James Hirschauer · Stefan Hoeche and 23 other authors

    This report, as part of the 2021 Snowmass Process, summarizes the current status of collider physics at the Energy Frontier, the broad and exciting future prospects identified for the Energy Frontier, the challenges and needs of future experiments, and indicates high priority research areas.

    ↳ hep-exhep-lathep-phhep-th+196 citations
66. 66*

    Dynamical evolution of $U(1)$ gauged Q-balls in axisymmetry

    Michael P. Kinach🇨🇦 · Matthew W. Choptuik🇨🇦

    We study the dynamics of $U(1)$ gauged Q-balls using fully non-linear numerical evolutions in axisymmetry. Focusing on two models with logarithmic and polynomial scalar field potentials, we numerically evolve perturbed gauged Q-ball configurations in order to assess their stability and determine the fate of unstable configurations. Our simulations suggest that there exist both stable and unstable branches of solutions with respect to axisymmetric perturbations. For solutions belonging to the stable branch, the gauged Q-balls respond to the perturbations by oscillating continuously or weakly radiating before returning to the initial configuration. For the unstable branch, the solutions are eventually destroyed and can evolve in several ways, such as dispersal of the fields to infinity or fragmentation into smaller gauged Q-balls. In some cases, we observe the formation of ring-like structures which we call "gauged Q-rings". We also investigate the stability of gauged Q-balls when the gauge coupling is small, finding that the behaviour of these configurations closely resembles that of ordinary (non-gauged) Q-balls.

    ↳ hep-thgr-qchep-phPRD(2023)·11 citations
67. 67*

    Perspectives on the Dark Sector

    Robert Brandenberger (McGill University)🇨🇦

    I present some new perspectives on Dark Matter, Dark Energy and the origin of structure in the Universe. First, I argue that in order to understand the two latter issues, one needs to go beyond a standard point particle effective field theory analysis. Next, I review recent work attempting to construct a unified dark sector model from Heterotic superstring theory. I finish by discussing a new research effort to obtain early Universe cosmology directly from a non-perturbative definition of superstring theory.

    ↳ hep-thastro-ph.COgr-qchep-ph3 citations
68. 68*

    An expedition to the islands of stability in the first-order causal hydrodynamics

    Rajesh Biswas🇮🇳 · Sukanya Mitra🇮🇳 · Victor Roy🇮🇳

    The recently proposed connection between the Lorentz invariance of stability and the speed of signal propagation has been tested for a first-order relativistic dissipative hydrodynamic theory. The fact that the stability situation in different reference frames agrees with each other only as long as the signal propagation respects causality, has been explicitly established for the theory, which is microscopically derived from the covariant kinetic equation in general hydrodynamic frames with arbitrary momentum-dependent interactions.

    ↳ nucl-thhep-phPLB(2023)·14 citations
69. 69*

    The hadronic running of the electroweak couplings from lattice QCD

    Marco Cè🇨🇭 · Antoine Gérardin🇫🇷 · Georg von Hippel🇩🇪 · Harvey B. Meyer🇩🇪 · Kohtaroh Miura🇩🇪 · Konstantin Ottnad🇩🇪 · Andreas Risch🇩🇪 · Teseo San José🇫🇷 · Hartmut Wittig🇩🇪

    The energy dependency (running) of the strength of electromagnetic interactions $\alpha$ plays an important role in precision tests of the Standard Model. The running of the former to the $Z$ pole is an input quantity for global electroweak fits, while the running of the mixing angle is susceptible to the effects of Beyond Standard Model physics, particularly at low energies. We present a computation of the hadronic vacuum polarization (HVP) contribution to the running of these electroweak couplings at the non-perturbative level in lattice QCD, in the space-like regime up to $Q^2$ momentum transfers of $7{\mathrm{GeV}}^2$. This quantity is also closely related to the HVP contribution to the muon $g-2$. We observe a tension of up to $3.5$ standard deviation between our lattice results for $\Delta {\alpha }_{\mathrm{had}}^{(5)}(-Q^2)$ and estimates based on the $R$-ratio for $Q^2$ in the $3$ to $7{\mathrm{GeV}}^2$ range. The tension is, however, strongly diminished when translating our result to the $Z$ pole, by employing the Euclidean split technique and perturbative QCD, which yields $\Delta {\alpha }_{\mathrm{had}}^{(5)}(M_Z^2)=0.02773(15)$. This value agrees with results based on the $R$-ratio within the quoted uncertainties, and can be used as an alternative to the latter in global electroweak fits.

    ↳ hep-lathep-phPoS(2022)·0 citations
70. 70*

    SU(5) aGUT: a minimal asymptotic grand unification model

    Giacomo Cacciapaglia🇫🇷 · Ammar Abdalgabar🇸🇦 · Corentin Cot🇫🇷 · Alan S. Cornell🇿🇦 · Aldo Deandrea🇫🇷 · Mohammed Omer Khojali🇸🇩

    We present a new grand unification paradigm, where gauge couplings do not need to be equal at any given scale, instead they run towards the same fixed point in the deep ultraviolet. We provide a concrete example based on SU(5) with a compactified extra space dimension. By construction, fermions are embedded in different SU(5) bulk fields, hence baryon number is conserved and proton decay is forbidden. The lightest Kaluza-Klein tier consists of stable states, providing an asymmetric Dark Matter candidate via their baryonic charges, with a mass of 2.4 TeV. The model features an interesting and predictive flavour structure.

    ↳ hep-thhep-phPoS(2023)·4 citations
71. 71*

    Localisation of Dirac eigenmodes and confinement in gauge theories: the Roberge-Weiss transition

    Marco Cardinali🇮🇹 · Massimo D'Elia🇮🇹 · Francesco Garosi🇮🇹 · Matteo Giordano🇭🇺

    Ample numerical evidence from lattice calculations shows a strong connection between the confining properties of gauge theories at finite temperature and the localisation properties of the low-lying Dirac eigenmodes. In this contribution we discuss recent progress on this topic, focussing on results for QCD at imaginary chemical potential ${\mu }_I/T=\pi$ at temperatures above the Roberge-Weiss transition temperature. These confirm the general picture of low modes turning from delocalised to localised at the deconfinement transition, in a previously unexplored setup with a genuine, physical transition in the presence of dynamical fermions. This further supports the use of Dirac eigenmodes as a tool to investigate the mechanisms behind confinement and the deconfinement transition.

    ↳ hep-latcond-mat.dis-nnhep-phhep-thEPJ Web Conf.(2022)·0 citations
72. 72*

    Toy model to understand oscillatory behavior in timelike nucleon form factors

    Ri-Qing Qian🇨🇳 · Zhan-Wei Liu🇨🇳 · Xu Cao🇨🇳 · Xiang Liu🇨🇳

    To understand the oscillatory behavior exhibited in the timelike electromagnetic form factors of nucleons, we propose a toy model based on the Jost function of the $N\bar{N}$ pair into the timelike form factors with the help of the distorted-wave Born approximation. By constructing a simple square-well potential reflecting the final-state interaction of $N\bar{N}$, we naturally represent the damped oscillatory phenomenon in the timelike electromagnetic form factors of nucleons. Especially, our study reveals that the ``period" of the oscillation is approximately determined by the Yukawa interaction range $1/m_{\pi }$. Other possible potentials are also discussed. The threshold enhancements of the cross sections for $e^{+}{e}^{-}\to n\bar{n}$, $\Lambda \bar{\Lambda }$, and ${\Lambda }_c{\bar{\Lambda }}_c$ can also be understand within this scenario.

    ↳ nucl-thhep-exhep-phnucl-exPRD(2023)·17 citations
73. 73*

    On chiral spin symmetry and the QCD phase diagram

    Owe Philipsen🇩🇪 · Leonid Ya. Glozman🇦🇹 · Peter Lowdon🇩🇪 · Robert D. Pisarski🇺🇸

    Recently, an approximate $SU(4)$ chiral spin-flavour symmetry was observed in multiplet patterns of QCD meson correlation functions, in a temperature range above the chiral crossover. This symmetry is larger than the chiral symmetry of massless QCD, and can only arise effectively when colour-electric quark-gluon interactions dynamically dominate the quantum effective action. At temperatures about three times the crossover temperature, these patterns disappear again, indicating the screening of colour-electric interactions, and the expected chiral symmetry is recovered. In this contribution we collect independent evidence for such an intermediate temperature range, based on screening masses and the pion spectral function. Both kinds of observables behave non-perturbatively in this window, with resonance-like peaks for the pion and its first excitation disappearing gradually with temperature. Using symmetry arguments and the known behaviour of screening masses at small densities, we discuss how this chiral spin symmetric band continues into the QCD phase diagram.

    ↳ hep-lathep-phnucl-thPoS(2023)·7 citations
74. 74*

    Probing the holographic model of $\mathcal{N}=4$ SYM rotating quark-gluon plasma

    Anastasia A. Golubtsova🇷🇺 · Nikita S. Tsegelnik🇷🇺

    We study Wilson loops in holographic duals of the $\mathcal{N}=4$ SYM quark-gluon plasma. For this we consider the Schwarzschild-$Ad{S}_5$ and Kerr-$Ad{S}_5$ black holes, which are dual to the non-rotating and rotating QGPs, correspondingly. From temporal Wilson loops we find the heavy quark potentials in both backgrounds. For the temperature above the critical one we observe the Coulomb-like behaviour of the potentials. We find that increasing the rotation the interquark distance decreases, we also see that the increase of the temperature yields the similar behaviour. Moreover, at high temperatures values of the potentials in Kerr-$Ad{S}_5$ are close to that one calculated in the Schwarzschild-$Ad{S}_5$ black hole. We also explore holographic light-like Wilson loops from which the jet-quenching parameters of a fast parton propagating in the QGP are extracted. We find that the rotation increases the value of the jet-quenching parameter. However, at high temperatures the jet-quenching parameters have a cubic dependence on the temperature as for the AdS black brane.

    ↳ hep-thgr-qchep-phPRD(2023)·34 citations
75. 75*

    GalaxyFlow: Upsampling Hydrodynamical Simulations for Realistic Mock Stellar Catalogs

    Sung Hak Lim🇺🇸 · Kailash A. Raman · Matthew R. Buckley🇺🇸 · David Shih🇺🇸

    Cosmological N-body simulations of galaxies operate at the level of "star particles" with a mass resolution on the scale of thousands of solar masses. Turning these simulations into stellar mock catalogs requires "upsampling" the star particles into individual stars following the same phase-space density. In this paper, we introduce two new upsampling methods. First, we describe GalaxyFlow, a sophisticated upsampling method that utilizes normalizing flows to both estimate the stellar phase space density and sample from it. Second, we improve on existing upsamplers based on adaptive kernel density estimation, using maximum likelihood estimation to fine-tune the bandwidth for such algorithms in a way that improves both the density estimation accuracy and upsampling results. We demonstrate our upsampling techniques on a neighborhood of the Solar location in two simulated galaxies: Auriga 6 and h277. Both yield smooth stellar distributions that closely resemble the stellar densities seen in the Gaia DR3 catalog. Furthermore, we introduce a novel multi-model classifier test to compare the accuracy of different upsampling methods quantitatively. This test confirms that GalaxyFlow estimates the density of the underlying star particles more accurately than methods based on kernel density estimation, at the cost of being more computationally intensive.

    ↳ astro-ph.GAastro-ph.IMhep-phMNRAS(2024)·11 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.