Tue·Sep 12, 2023Tuesday·September 12, 2023

1. 01*

   $CP$ issues in the SM from a view point of spontaneous $CP$ violation

   Daijiro Suematsu🇯🇵

   The standard model (SM) has several issues related to the $CP$ violation which could give clues to search physics beyond the SM. They are a $CP$ phase in the CKM matrix, the strong $CP$ problem, $CP$ phases in the PMNS matrix and $CP$ asymmetry in lepton number violating processes related to baryon number asymmetry. We consider a model which could give a unified explanation for them in a framework of spontaneous $CP$ violation. It is an extension of the SM with vector-like fermions and singlet scalars. In this model, they are explained by a common complex phase caused in the spontaneous $CP$ violation. We present concrete examples for them and also discuss some relevant phenomenology.

   hep-phPRD(2023)·9 citations
2. 02*

   All-charm tetraquark mass and possible quantum numbers of X(6900)

   Morgan Kuchta🇵🇱

   In this work we propose possible quantum numbers of X(6900) and suggest a model for it internal structure that explains its unusually high mass. We solve the Schrödinger Equation with Mathematica 12, first for charmonium spectrum, then for all-charm tetraquark spectrum which is understood as a pair of two-particle states, mesons or diquark-antidiquark states. The obtained candidates for all-charm tetraquark will be separated into contributors to various resonances and structures that are visible in the experiments then an explanation for the prominence of X(6900) will be proposed.

   hep-ph2 citations
3. 03*

   The unintegrated gluon distribution from the GBW and BGK models

   G.R.Boroun🇮🇷

   The gluon distribution is obtained from the Golec-Biernat-W$\ddot{\mathrm{u}}$sthoff (GBW) and Bartels, Golec-Biernat and Kowalski (BGK) models at low $x$. We derive analytical results for the unintegrated color dipole gluon distribution function at small transverse momentum, which provides useful information to constrain the $k_t$-shape of the unintegrated gluon distribution in comparison with the unintegrated gluon distribution (UGD) models. The longitudinal proton structure function $F_L(x,Q^2)$ from the $k_t$ factorization scheme, using the unintegrated gluon density is computed. We compare the predictions for the on-shell and twist-2 corrections with the HERA data and the CJ15 parametrization method for $F_L$. We show that this method is very well described the experimental data within the on-shell and twist-2 framework. Effects of parameters on $F_L$, where charm contribution is taken into account, are investigated. These results are in good agreement with the data at fixed $W$.

   hep-phEPJA(2024)·18 citations
4. 04*

   Probing the Supersymmetry-Mass Scale With F-term Hybrid Inflation

   G. Lazarides🇬🇷 · C. Pallis🇬🇷

   We consider F-term hybrid inflation and supersymmetry breaking in the context of a model which largely respects a global U(1) R symmetry. The Kaehler potential parameterizes the Kaehler manifold with an enhanced U(1)x(SU(1,1)/U(1)) symmetry, where the scalar curvature of the second factor is determined by the achievement of a supersymmetry-breaking de Sitter vacuum without ugly tuning. The magnitude of the emergent soft tadpole term for the inflaton can be adjusted in the range (1.2-460) TeV -- increasing with the dimensionality of the representation of the waterfall fields -- so that the inflationary observables are in agreement with the observational requirements. The mass scale of the supersymmetric partners turns out to lie in the region (0.09-253) PeV which is compatible with high-scale supersymmetry and the results of LHC on the Higgs boson mass. The mu parameter can be generated by conveniently applying the Giudice-Masiero mechanism and assures the out-of-equilibrium decay of the R saxion at a low reheat temperature Trh<~163 GeV.

   hep-phastro-ph.COhep-thPRD(2023)·20 citations
5. 05*

   CMS results for the $\gamma \gamma$ production at the LHC: do they give a hint for a Higgs boson of the maximally CP symmetric two-Higgs-doublet model?

   M. Maniatis🇨🇱 · O. Nachtmann🇩🇪

   Recent measurements of the CMS experiment at the LHC show possibly, with about 3 $\sigma$ significance, a resonance in di-photon events with an invariant mass of 95.4 GeV. If this resonance can be confirmed, this could be a hint for a new elementary particle beyond the Standard Model. An additional Standard-model-like Higgs boson with this mass could be excluded by the CMS experiment. We investigate whether this resonance could fit into a two-Higgs-doublet model highly constrained by CP symmetry, the so-called maximally-CP-symmetric model (MCPM). In the strict symmetry limit of the MCPM only the fermions of the third generation obtain masses. We discuss a mechanism where the first and second generation fermions get masses through effects from interactions with very high mass particles. The latter can be integrated out at LHC energies giving effective Lagrangian terms, among them these mass terms. This procedure also gives us a Cabibbo-Kobayashi-Maskawa (CKM) matrix which automatically satisfies some salient structural features observed in experiments. We call the resulting theory MCPM'. Our finding shows that indeed the enhancement measured by CMS could originate from the pseudoscalar Higgs boson $h^{\prime \prime }$ of this model. According to the model the boson $h^{\prime \prime }$ would mainly be produced in the Drell-Yan reaction by charm-anticharm-quark fusion. The main decay mode of $h^{\prime \prime }$ is predicted to be $h^{\prime \prime }\to c\bar{c}$. We then consider the so called oblique parameters $S$, $T$, $U$ which give us an allowed region for the mass of the scalar Higgs boson $h^{\prime }$ versus that of the charged ones $H^{\pm }$ of the MCPM'. We calculate the effect of these charged bosons $H^{\pm }$ in the leptonic decays of the charm mesons $D^{\pm }$ and the charm-strange mesons $D_s^{\pm }$. Our results indicate that the mass $m_{H^{\pm }}$ of the charged Higgs bosons $H^{\pm }$ of the MCPM' should be around 300 GeV.

   hep-phPRD(2025)·9 citations
6. 06*

   Equation of spin motion for a particle with electric and magnetic charges and dipole moments

   Alexander J. Silenko🇷🇺

   The general classical equation of spin motion is rigorously derived for a particle with electric and magnetic charges and dipole moments in electromagnetic fields. The equation describing the spin motion relative to the momentum direction in storage rings is also obtained. The importance of the derivation follows from a possible appearance of magnetic charges and EDMs due to the pseudoscalar \emph{CP}-violating electromagnetic interaction caused by dark matter axions.

   hep-phPhys.Scripta(2024)·3 citations
7. 07*

   Z' Mediated right-handed Neutrinos from Meson Decays at the FASER

   Jiale Li🇨🇳 · Wei Liu🇨🇳 · Hao Sun🇨🇳

   We investigate the pair production of right-handed neutrinos mediated by a $Z^{\prime }$ mainly from the meson decays at the FASER detector of the HL-LHC. The $Z^{\prime }$ can be the additional gauge boson in either the $U(1{)}_{B-L}$ or sterile $\nu$-specific $U(1{)}_s$ model. Taking the gauge coupling or the kinetic mixing at the current limits, we analyse the sensitivity to the masses of the heavy neutrinos, $M_N$, and active-sterile mixing, $|V_{lN}{|}^2$, of the FASER2. In a background free scenario, for the $U(1{)}_{B-L}$ case, FASER2 is able to probe $|V_{lN}{|}^2\approx 10^{-8}$ when $M_N\sim 0.3$ GeV, which is comparable to the current limits from the beam dump experiments. When comes to the $U(1{)}_s$ model, FASER2 can probe $|V_{lN}{|}^2\approx 10^{-10}$, which is better than the current limits for at least one magnitude, in all three flavours. A proposed long-lived particle detector, FACET, is also studied, while no significant difference from FASER2 is derived.

   hep-phPRD(2024)·13 citations
8. 08*

   An introduction to the parton and hadron cascade model PACIAE 3.0

   An-Ke Lei🇨🇳 · Yu-Liang Yan🇨🇳 · Dai-Mei Zhou🇨🇳 · Zhi-Lei She🇨🇳 · Liang Zheng🇨🇳 · Gao-Chan Yong🇨🇳 · Xiao-Mei Li🇨🇳 · Gang Chen🇨🇳 · Xu Cai🇨🇳 · Ben-Hao Sa🇨🇳

   We introduce a parton and hadron cascade model PACIAE 3.0 based on PYTHIA 6.428 and the PACIAE 2.2 program series. The simulation framework of C-, B-, and A-loops are designed for the high energy ($\sqrt{s_{NN}}\ge 3$ GeV) and low energy ($\sqrt{s_{NN}}<3$ GeV) nuclear collisions, respectively, in PACIAE 3.0. In the C-loop simulation, the parton-parton inelastic scattering processes are added in the partonic rescattering process. The single string structure and multiple string interaction mechanism have been introduced investigating the strangeness enhancement in C- and B-loop. An improved mapping relation between the centrality percentage definition and the impact parameter definition is proposed responding the observation of $b_{max}\approx 20$ fm from ALICE, ATLAS, and CMS collaborations. We have extensively modified the phenomenological coalescence hadronization model. The PACIAE 3.0 model simulated results of particle yield, transverse momentum distribution, and rapidity distribution well reproduce, respectively, the experimental data measured at FOPI, E895, RHIC, and LHC energies.

   hep-phnucl-thPRC(2023)·21 citations
9. 09*

   The cosmological collider signal in the non-BD initial states

   Yuan Yin🇨🇳

   We investigate the cosmological collider (CC) signal arising from the tree-level exchange of a scalar spectator particle with a non-Bunch Davies (BD) initial state. We decompose the inflaton correlators into seed integrals, which we compute analytically by solving the bootstrap equations. We show that the non-BD initial state eliminates the Hubble scale Boltzmann suppression $e^{-\pi m/H}$ that usually affects the CC signal. Consequently, in this scenario, the CC can probe an energy scale much higher than the inflationary Hubble scale $H$.

   hep-phastro-ph.COPRD(2024)·16 citations
10. 10*

    Shear viscosity of rotating, hot, and dense spin-half fermionic systems from quantum field theory

    Sarthak Satapathy🇮🇳 · Rajeev Singh🇺🇸 · Pushpa Panday🇮🇳 · Salman Ahamad Khan🇮🇳 · Debarshi Dey🇮🇳

    In this study, we calculate the shear viscosity for rotating fermions with spin-half under conditions of high temperature and density. We employ the Kubo formalism, rooted in finite-temperature quantum field theory, to compute the field correlation functions essential for this evaluation. The one-loop diagram pertinent to shear viscosity is analyzed within the context of curved space, utilizing tetrad formalism as an effective approach in cylindrical coordinates. Our findings focus on extremely high angular velocities, ranging from 0.1 to 1 GeV, which align with experimental expectations. Furthermore, we explore the inter-relationship between the chemical potential and angular velocity within the scope of this study.

    hep-phhep-thnucl-th2 citations
11. 11*

    QCD parameters and SM-high precisions from $e^{+}{e}^{-}\to$ Hadrons : Summary

    Stephan Narison (LUPM-CNRS/IN2P3, Univ. Montpellier-FR and iHEPMAD, Univ. Antananarivo-MG)🇫🇷

    In this talk, I summarize the results obtained recently in Ref.\,\cite{SNe} using the PDG 22 compilation of the $e^{+}{e}^{-}\to$ Hadrons $\oplus$ the recent CMD3 data for the pion form factor. Using the gluon condensate $⟨{\alpha }_s{G}^2⟩=(6.49\pm 0.35)\times 10^{-2}$ GeV${}^4$ from heavy quark sum rules, the extracted QCD four-quark and dimension eight condensate condensates values are: $\rho {\alpha }_s⟨\bar{\psi }\psi {⟩}^2=(5.98\pm 0.64)\times 10^{-4}$ GeV${}^6$ and $d_8=(4.3\pm 3.0)\times 10^{-2}$ GeV${}^8$ from the ratio ${\mathcal{R}}_{10}$ of Laplace sum rules to order ${\alpha }_s^4$. Inversely using these estimated values of the condensates, we obtain from ${\mathcal{R}}_{10}$: $⟨{\alpha }_s{G}^2⟩=(6.12\pm 0.61)\times 10^{-2}$ GeV${}^4$ which leads to the average $(6.40\pm 0.30)\times 10^{-2}$ GeV${}^4$. %from light and heavy quark systems. Using the lowest $\tau$-like decay moment, the mean result of Fixed Order (FO) and Contour Improved (CI) PT series within the standard OPE is : ${\alpha }_s(M_{\tau })=0.3385(50)(136{)}_{syst}$ [resp. $0.3262(37)(78{)}_{syst}$] to order ${\alpha }_s^4$ [resp. ${\alpha }_s^5$] leading to ${\alpha }_s(M_Z)$=0.1207(17)(3) [resp. 0.1193(11)(3)], while the sum of the non-perturbative contribution at $M_{\tau }$ is\,: ${\delta }_{NP}^V(M_{\tau })=(2.3\pm 0.2)\times 10^{-2}$. Using the same data, one also obtains the LO hadronic vacuum polarization to the muon and $\tau$ anomalous magnetic moments: $a_{\mu }{|}_{l.o}^{hvp}=(7036.5\pm 38.9)\times 10^{-11},a_{\tau }{|}_{l.o}^{hvp}=(3494.8\pm 24.7)\times 10^{-9}$ which leads to : $\Delta a_{\mu }\equiv a_{\mu }^{exp}-a_{\mu }^{th}=(143\pm 42_{th}\pm 22_{exp})\times 10^{-11}$ indicating about 3$\sigma$ discrepancy between the SM predictions and experiment. One also finds: ${\alpha }^{(5)}(M_Z){|}_{had}=(2766.3\pm 4.5)\times 10^{-5}$.

    hep-phhep-exhep-latNucl.Part.Phys.Proc.(2024)·6 citations
12. 12*

    Study of damped oscillating structures from charged and neutral K-meson electromagnetic form factors data

    Stanislav Dubnička🇸🇰 · Anna Zuzana Dubničková🇸🇰 · Lukáš Holka🇸🇰 · Andrej Liptaj🇸🇰

    The damped oscillating structures (OS) were recently revealed in the proton "effective" form factor (FF) data. For the time being they can be neither confirmed nor disproved by investigations of timelike data on the individual proton electric and proton magnetic FFs because their precision and reliability (especially of the proton electric FF data) has not achieved required level for this aim. On the other hand, conjectures that the OS are direct manifestations of the quark-gluon structure of the proton indicate that they must not be specific only for the proton and neutron, but that they should be present also for other hadrons. This opens a plausibility to find damped oscillatory structures also from the EM FFs data of such hadrons, for which adequate EM FFs data exist, by using the same procedure as for the proton. Consequently in this paper damped oscillatory structures are investigated in the EM FFs data of the charged and neutral $K$-mesons to be extracted from the corresponding production cross sections, ${\sigma }_{tot}^{bare}(e^{+}{e}^{-}\to K^{+}{K}^{-})$ measured from the threshold up to 64 GeV${}^2$ and ${\sigma }_{tot}^{bare}(e^{+}{e}^{-}\to K_s{K}_L)$ measured from the threshold up to 9.5 GeV${}^2$ of the total c.m. energy squared. The following results have been obtained. If the charged and neutral K-meson EM FFs timelike data are described by the three parametric formula by means of which OS have been revealed from the "effective" proton FF data then OS appear. If physically well founded Unitary and Analytic model of the K-meson EM structure is used for a description of the charged K-meson EM FFs data, no OS are visible. However, in the case of the neutral K-meson EM FF data one cannot make a definite decision. The overall results indicate that OS obtained from the "effective" proton FF data are likely an artefact of the three parametric formula which does not describe these data well.

    hep-phEPJA(2023)·3 citations
13. 13*

    LHC Study of Third-Generation Scalar Leptoquarks with Machine-Learned Likelihoods

    Ernesto Arganda🇪🇸 · Daniel A. Díaz🇦🇷 · Andres D. Perez🇪🇸 · Rosa M. Sandá Seoane🇪🇸 · Alejandro Szynkman🇦🇷

    We study the impact of machine-learning algorithms on LHC searches for leptoquarks in final states with hadronically decaying tau leptons, multiple $b$-jets, and large missing transverse momentum. Pair production of scalar leptoquarks with decays only into third-generation leptons and quarks is assumed. Thanks to the use of supervised learning tools with unbinned methods to handle the high-dimensional final states, we consider simple selection cuts which would possibly translate into an improvement in the exclusion limits at the 95$\%$ confidence level for leptoquark masses with different values of their branching fraction into charged leptons. In particular, for intermediate branching fractions, we expect that the exclusion limits for leptoquark masses extend to $\sim$1.3 TeV. As a novelty in the implemented unbinned analysis, we include a simplified estimation of some systematic uncertainties with the aim of studying their possible impact on the stability of the results. Finally, we also present the projected sensitivity within this framework at 14 TeV for 300 and 3000 fb${}^{-1}$ that extends the upper limits to $\sim$1.6 and $\sim$1.8 TeV, respectively.

    hep-phhep-exPRD(2024)·14 citations
14. 14*

    The role of de-excitation in the final-state interactions of protons in neutrino-nucleus interactions

    Anna Ershova🇫🇷 · Kajetan Niewczas🇧🇪 · Sara Bolognesi🇫🇷 · Alain Letourneau🇫🇷 · Jean-Christophe David🇫🇷 · José Luís Rodríguez-Sánchez🇪🇸 · Jan Sobczyk🇵🇱 · Adrien Blanchet🇨🇭 · Margherita Buizza Avanzini🇫🇷 · Jaafar Chakrani🇫🇷 · Joseph Cugnon🇧🇪 · Stephen Dolan🇨🇭 and 8 other authors

    Present and next generation of long-baseline accelerator experiments are bringing the measurement of neutrino oscillations into the precision era with ever-increasing statistics. One of the most challenging aspects of achieving such measurements is developing relevant systematic uncertainties in the modeling of nuclear effects in neutrino-nucleus interactions. To address this problem, state-of-the-art detectors are being developed to extract detailed information about all particles produced in neutrino interactions. To fully profit from these experimental advancements, it is essential to have reliable models of propagation of the outgoing hadrons through nuclear matter able to predict how the energy is distributed between all the final-state observed particles. In this article, we investigate the role of nuclear de-excitation in neutrino-nucleus scattering using two Monte Carlo cascade models: NuWro and INCL coupled with the de-excitation code ABLA. The ablation model ABLA is used here for the first time to model de-excitation in neutrino interactions. As input to ABLA, we develop a consistent simulation of nuclear excitation energy tuned to electron-scattering data. The paper includes the characterization of the leading proton kinematics and of the nuclear cluster production during cascade and de-excitation. The observability of nuclear clusters as vertex activity and their role in a precise neutrino energy reconstruction is quantified.

    hep-phhep-exPRD(2023)·14 citations
15. 15*

    B meson decays in covariant confined quark model

    Stanislav Dubnička🇸🇰 · Anna Zuzana Dubničková🇸🇰 · Mikhail Alekseevich Ivanov🇷🇺 · Andrej Liptaj🇸🇰

    The aim of this text to present the covariant confined quark model (CCQM) and review its applications to the decays of $B$ mesons. We do so in the context of existing experimental measurements and theoretical results of other authors, which we review also. The physics principles are in detail exposed for the CCQM, the other results (theoretical and experimental) are surveyed in an enumerative way with comments. We proceed by considering successively three categories of decay processes: leptonic, semileptonic and non-leptonic.

    hep-phSymmetry(2023)·1 citation
16. 16*

    Improved method to determine the ${\Xi }_c-{\Xi }_c^{\prime }$ mixing

    Hang Liu🇨🇳 · Wei Wang🇨🇳 · Qi-An Zhang🇨🇳

    We develop an improved method to explore the ${\Xi }_c-{\Xi }_c^{\prime }$ mixing which arises from the flavor SU(3) and heavy quark symmetry breaking. In this method, the flavor eigenstates under the SU(3) symmetry are at first constructed and the corresponding masses can be nonperturbatively determined. Matrix elements of the mass operators which break the flavor SU(3) symmetry sandwiched by the flavor eigenstates are then calculated. Diagonalizing the corresponding matrix of Hamiltonian gives the mass eigenstates of the full Hamiltonian and determines the mixing. Following the previous lattice QCD calculation of ${\Xi }_c$ and ${\Xi }_c^{\prime }$, and estimating an off-diagonal matrix element, we extract the mixing angle between the ${\Xi }_c$ and ${\Xi }_c^{\prime }$. Preliminary numerical results for the mixing angle confirm the previous observation that such mixing is incapable to explain the large SU(3) symmetry breaking in semileptonic decays of charmed baryons.

    hep-phPRD(2024)·17 citations
17. 17*

    How robust are gravitational wave predictions from cosmological phase transitions?

    Peter Athron🇨🇳 · Lachlan Morris🇦🇺 · Zhongxiu Xu🇨🇳

    Gravitational wave (GW) predictions of cosmological phase transitions are almost invariably evaluated at either the nucleation or percolation temperature. We investigate the effect of the transition temperature choice on GW predictions, for phase transitions with weak, intermediate and strong supercooling. We find that the peak amplitude of the GW signal varies by a factor of a few for weakly supercooled phase transitions, and by an order of magnitude for strongly supercooled phase transitions. The variation in amplitude for even weakly supercooled phase transitions can be several orders of magnitude if one uses the mean bubble separation, while the variation is milder if one uses the mean bubble radius instead. We also investigate the impact of various approximations used in GW predictions. Many of these approximations introduce at least a 10% error in the GW signal, with others introducing an error of over an order of magnitude.

    hep-phastro-ph.COJCAP(2024)·49 citations
18. 18*

    Interactions between several types of cosmic strings

    Kohei Fujikura🇯🇵 · Siyao Li🇯🇵 · Masahide Yamaguchi🇯🇵

    We study the interaction of several types of static straight cosmic strings, including local strings, global strings, and bosonic superconducting strings with and without magnetic currents. First, we evaluate the interaction energy of two widely separated cosmic strings using the point source formalism and show that the most dominant contribution to the interaction energy comes from the excitation of the lightest mediator particles in a underlying theory. The interaction energy at arbitrary separation distances is then analyzed numerically by the gradient flow method. It turns out that an additional scalar field introduced in the bosonic superconducting string becomes an additional source of attraction. For such a bosonic superconducting string, we find that a string with two winding numbers is energetically favorable compared to two strings with a single winding number in a certain parameter region. Our analysis reveals that a phase structure of bosonic superconducting strings is richer than that of local and global strings and that the formation of bound states at intersections of bosonic superconducting strings is favored.

    hep-phastro-ph.COhep-thJHEP(2023)·8 citations
19. 19*

    Electromagnetic energy transfer processes in Effective Electro-Magneto Dynamics of axions

    Andras Patkos🇭🇺

    Oscillating and dissipative energy exchange between the electromagnetic and axion fields is investigated in an effective electro-magneto dynamical (EEMD) model theory, implying the coexistence of axions with hypothetic magnetic charges. An exact formula is presented for the energy transfer between the electromagnetic and axionic sectors. In a first example we compute analytically the homogeneously oscillating electric and magnetic field configurations generated by the combined action of a constant static magnetic field and a periodically oscillating axion condensate. In the second example the electromagnetic radiative energy loss of a gravitationally bound axion configuration is computed in the EEMD model. As a result an asymptotic $\sim t^{1/5}$ temporal increase of the clump size is found also in EEMD.

    hep-phhep-thMod.Phys.Lett.A(2023)·5 citations
20. 20*

    Next-to-leading order QCD corrections to the form factors of $B$ to scalar meson decays

    Xue-Ying Han🇨🇳 · Long-Shun Lu🇨🇳 · Cai-Dian Lü🇨🇳 · Yue-Long Shen🇨🇳 · Bo-Xuan Shi🇨🇳

    We calculate the next-to-leading order QCD corrections to $B$ to scalar meson form factors from QCD light-cone sum rules with $B$ meson light-cone distribution amplitudes. We demonstrate that the $B$ meson-to-vacuum correlation functions can be factorized into the convolution of short-distance coefficients and light-cone distribution amplitudes at the one-loop level and find that only ${\varphi }_B^{+}(\omega ,\mu )$ contributes to the form factors. We then employ the $z$-parameterization combined with constraints from strong coupling constants to reconstruct the $q^2$ dependence of the form factors in the whole kinematic allowed regions. Due to the large cancellations between the hard functions and the jet functions, the next-to-leading order results show a modest increase of approximately 5\% compared to the leading order results. Based on the results of form factors, we predict the branching ratios of semi-leptonic $B\to S\ell {\bar{\nu }}_{\ell }$ and $B\to S{\nu }_{\ell }{\bar{\nu }}_{\ell }$ processes, as well as several angular observables, such as forward-backward asymmetries, "flat terms" and lepton polarization asymmetries. We compare these results with calculations from other methods. Experimental verification of these results is required in future experiments.

    hep-phJHEP(2023)·11 citations
21. 21*

    Axion Domain Walls, Small Instantons, and Non-Invertible Symmetry Breaking

    Clay Cordova🇺🇸 · Sungwoo Hong🇰🇷 · Lian-Tao Wang🇺🇸

    Non-invertible global symmetry often predicts degeneracy in axion potentials and carries important information about the global form of the gauge group. When these symmetries are spontaneously broken they can lead to the formation of stable axion domain wall networks which support topological degrees of freedom on their worldvolume. Such non-invertible symmetries can be broken by embedding into appropriate larger UV gauge groups where small instanton contributions lift the vacuum degeneracy, and provide a possible solution to the domain wall problem. We explain these ideas in simple illustrative examples and then apply them to the Standard Model, whose gauge algebra and matter content are consistent with several possible global structures. Each possible global structure leads to different selection rules on the axion couplings, and various UV completions of the Standard Model lead to more specific relations. As a proof of principle, we also present an example of a UV embedding of the Standard Model which can solve the axion domain wall problem. The formation and annihilation of the long-lived axion domain walls can lead to observables, such as gravitational wave signals. Observing such signals, in combination with the axion coupling measurements, can provide valuable insight into the global structure of the Standard Model, as well as its UV completion.

    hep-phhep-thJHEP(2024)·66 citations
22. 22*

    Restoring Naturalness via Conjugate Fermions

    Andrei Angelescu🇩🇪 · Andreas Bally🇩🇪 · Florian Goertz🇩🇪 · Maya Hager🇩🇪

    We propose a novel mechanism for cancelling the leading order contribution to the potential in composite Higgs scenarios. The mechanism relies on the splitting of a real representation of the global symmetry into a complex representation and its conjugate of the unbroken group. We identify two cosets one of which includes a custodial symmetry. A numerical analysis is performed in a phenomenological three-site model and the resulting fine-tuning is analysed. The cancelling of the leading order potential results in a drastic reduction of the fine-tuning. For a symmetry breaking scale of the strong sector as high as $f=1600$ GeV, fine-tuning can be as good as $10\%$ or even better. We discuss a possible interpretation in the 5D holographic dual. Unique signatures of the model include quarks with baryon number $B=2/3$ with highly distinctive decays which can be looked for at the LHC.

    hep-phPRD(2024)·5 citations
23. 23*

    Regurgitated Dark Matter

    TaeHun Kim🇰🇷 · Philip Lu🇰🇷 · Danny Marfatia🇺🇸 · Volodymyr Takhistov🇯🇵

    We present a new paradigm for the production of the dark matter (DM) relic abundance based on the evaporation of early Universe primordial black holes (PBHs) themselves formed from DM particles. As a concrete realization, we consider a minimal model of the dark sector in which a first-order phase transition results in the formation of Fermiball remnants that collapse to PBHs, which then emit DM particles. We show that the regurgitated DM scenario allows for DM in the mass range $\sim 1$ GeV $-10^{16}$ GeV, thereby unlocking parameter space considered excluded.

    hep-phastro-ph.COastro-ph.HEhep-exPRD(2024)·34 citations
24. 24*

    Revisiting Cosmological Constraints on Supersymmetric SuperWIMPs

    Meera Deshpande🇦🇺 · Jan Hamann🇦🇺 · Dipan Sengupta🇦🇺 · Martin White🇦🇺 · Anthony G. Williams🇦🇺 · Yvonne Y. Y. Wong🇦🇺

    SuperWIMPs are extremely weakly interacting massive particles that inherit their relic abundance from late decays of frozen-out parent particles. Within supersymmetric models, gravitinos and axinos represent two of the most well-motivated superWIMPs. In this paper we revisit constraints on these scenarios from a variety of cosmological observations that probe their production mechanisms as well as the superWIMP kinematic properties in the early Universe. We consider in particular observables of Big Bang Nucleosynthesis and the Cosmic Microwave Background (spectral distortion and anisotropies), which limit the fractional energy injection from the late decays, as well as warm and mixed dark matter constraints derived from the Lyman-$\alpha$ forest and other small-scale structure observables. We discuss complementary constraints from collider experiments, and argue that cosmological considerations rule out a significant part of the gravitino and the axino superWIMP parameter space.

    hep-phastro-ph.COhep-exEPJC(2024)·5 citations
25. 25*

    The arions generation by magnetodipole waves of pulsars and magnetars in a constant magnetic field

    V.I. Denisov🇷🇺 · G.A. Dantsev🇷🇺 · V.I. Priclonsky🇷🇺 · I.P. Denisova🇷🇺 · O.N. Gavrish🇷🇺

    The influence of the gravitational fields of pulsars and magnetars on the arion emission during the propagation of magnetodipole waves in a constant magnetic field has been evaluated. The solution of the equation was obtained and the flux of arions emitted by magnetodipole waves during their propagation in a constant magnetic field was found. It is shown that the amplitude of the born arion wave at a distance from the source of magnetodipole radiation of a pulsar or magnetar $(r\to \infty )$ in the considered case tends to a constant value. The intensity of the arion emission in the solid angle element and the amount of arion energy $\overline{I}$, emitted in all directions per unit time grow quadratically with increasing distance, traveled by the magnetodipole radiation of a pulsar or magnetar in a constant magnetic field. Such growth of the energy of the born arion wave is due to the fact that in the considered problem constant magnetic field is defined in the whole space. In reality, the galactic and intergalactic magnetic fields can be represented in this form only in regions of space of finite dimensions, outside of which the force lines of their induction vector are curved. Therefore, it is possible to apply these results only in a region of space for which $r\le L_{coh}<\infty$, where $L_{coh}$ is the coherence length, the distance at which the force lines of the induction vector can be considered as straight lines. An estimate for the value of the coupling constant of photons with arions is obtained.

    hep-phastro-ph.GAastro-ph.HEgr-qcGrav.Cosmol.(2024)·4 citations
26. 26*

    Signatures of particle collisions near extreme black holes

    Delilah E. A. Gates🇺🇸 · Shahar Hadar🇮🇱

    Finite-energy particles in free fall can collide with diverging center-of-mass energy near rapidly rotating black holes. What are the most salient observational signatures of this remarkable geometric effect? Here we revisit the problem from the standpoint of the near-horizon extreme Kerr geometry, where these collisions naturally take place. It is shown that the ingoing particle kinematics admits a simple, universal form. Given a scattering cross section, determination of emission properties is reduced to evaluation of particular integrals on the sky of a near-horizon orbiting particle. We subsequently apply this scheme to the example of single-photon bremsstrahlung, substantiating past results which indicate that ejected particles are observable, but their energies are bounded by the rest masses of the colliding particles. Our framework is readily applicable for any scattering process.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRD(2024)·4 citations
27. 27*

    Looping the loops: a tale of elliptic dual Feynman integrals

    Mathieu Giroux🇨🇦 · Andrzej Pokraka🇺🇸 · Franziska Porkert🇩🇪 · Yoann Sohnle🇸🇪

    In this talk, we review a loop-by-loop approach used to generate differential equations for multi-scale (dual) Feynman integrals. We illustrate the method on a well-established example: the unequal mass elliptic sunrise.

    ↳ hep-thhep-phPoS(2024)·2 citations
28. 28*

    The Last Three Seconds: Packed Message delivered by Tides in Binary Neutron Star Mergers

    Hao-Jui Kuan🇩🇪 · Kostas D. Kokkotas🇩🇪

    It is known that the leading-order tidal effects in gravitational waveforms can be quantified by tidal deformability, while higher order terms, e.g., harmonic overtones of Love number and dynamical tides, have not been well-investigated yet. The concept of a ``form factor'', which is different from while resembles the effective tidal deformability, for the tidal interactions between neutron stars in coalescing binaries is illustrated here. The form factor effectively incorporates the contribution of dynamical tides. The dependence of tidal form factor on tidal deformability, spins, and inclination angles is modeled and expressed in a closed form.

    ↳ gr-qchep-phPRD(2023)·13 citations
29. 29*

    Suppression of the multiplicity fluctuations in particle correlations

    Chong Ye🇨🇳 · Hong-Hao Ma🇨🇳 · Dan Wen🇨🇳 · Philipe Mota🇧🇷 · Wei-Liang Qian🇨🇳 · Rui-Hong Yue🇨🇳

    Multiplicity fluctuations play a crucial role in relativistic heavy-ion collisions. In this work, we explore how the multiplicity fluctuations can be effectively suppressed in the measurement of particle correlations. In particular, through proper normalization, particle correlations can be evaluated in a manner irrelevant to multiplicity. When the multiplicity fluctuations are adequately extracted, Monte Carlo simulations show that the remaining correlations possess distinct features buried in the otherwise overwhelming fluctuations. Moreover, we argue that such a normalization scheme naturally agrees with the multi-particle correlator, which can be evaluated using the Q-vectors. The implications of the present study in the data analysis are also addressed.

    ↳ nucl-thhep-phUniverse(2023)·3 citations
30. 30*

    Searching for topological dark matter in LIGO data

    Lavinia Heisenberg🇩🇪 · David Maibach🇩🇪 · Doğa Veske🇩🇪

    Gravitational-wave interferometers have been recently proposed as a promising probe in searches for dark matter. These highly sensitive instruments are potentially able to detect the interactions of dark matter with the detector's hardware. In this work, we explore the possibilities of discovering topological dark matter with the LIGO detectors. We analyze domain walls consisting of dark matter passing through the Earth, leaving traces in multiple detectors simultaneously. Considering dark matter interactions with light in the interferometer, and with the beam splitter, we perform the first analysis of topological dark matter with gravitational-wave strain data. We examine whether astrophysically unexpected triggers could be explained by domain-wall passages. We find that all of the binary black hole mergers we analyze favor the binary black hole merger hypothesis rather than the domain-wall hypothesis, with the closest being GW190521. Moreover, we find that some topological dark matter signals can be caught by binary black hole searches. Finally, we find that special types of glitches in the measurement data can inevitably limit the dark matter searches for certain parameters. These results are expected to guide future searches and analyses.

    ↳ gr-qcastro-ph.COastro-ph.HEhep-ph+1PRD(2024)·4 citations
31. 31*

    Instability and backreaction of massive spin-2 fields around black holes

    William E. East🇨🇦 · Nils Siemonsen🇨🇦

    A massive spin-2 field can grow unstably around a black hole, giving rise to a potential probe of the existence of such fields. In this work, we use time-domain evolutions to study such instabilities. Considering the linear regime by solving the equations generically governing a massive tensor field on the background of a Kerr black hole, we find that black hole spin increases the growth rate and, most significantly, the mass range of the axisymmetric (azimuthal number $m=0$) instability, which takes the form of the Gregory-Laflamme black string instability for zero spin. We also consider the superradiant unstable modes with $1\le m\le 3$, extending previous results to higher spin-2 masses, black hole spins, and azimuthal numbers. We find that the superradiant modes grow slower than the $m=0$ modes, except for a narrow range of high spins and masses, with $m=1$ and 2 requiring a dimensionless black hole spin of $a_{\mathrm{BH}}\gtrsim 0.95$ to be dominant. Thus, in most of the parameter space, the backreaction of the $m=0$ instability must be taken into account when using black holes to constrain massive spin-2 fields. As a simple model of this, we consider nonlinear evolutions in quadratic gravity, in particular Einstein-Weyl gravity. We find that, depending on the initial perturbation, the black hole may approach zero mass with the curvature blowing up in finite time, or can saturate at a larger mass with a surrounding cloud of the ghost spin-2 field.

    ↳ gr-qcastro-ph.HEhep-phhep-thPRD(2023)·40 citations
32. 32*

    Superradiant growth anomaly magnification in evolution of vector bosonic condensates bounded by a Kerr black hole with near-horizon reflection

    Nayun Jia🇨🇳 · Yin-Da Guo🇨🇳 · Gui-Rong Liang🇨🇳 · Zhan-Feng Mai🇨🇳 · Xin Zhang🇺🇸

    Ultralight vector particles can form evolving condensates around a Kerr black hole (BH) due to superradiant instability. We study the effect of near-horizon reflection on the evolution of this system: by matching three pieces of asymptotic expansions of the Proca equation in Kerr metric and considering the leading order in the electric mode, we present explicit analytical expressions for the corrected spectrum and the superradiant instability rates. Particularly, in high-spin BH cases, we identify an anomalous situation where the superadiance rate is temporarily increased by the reflection parameter $\mathcal{R}$, which also occurs in the scalar scenario, but is largely magnified in vector condensates due to a faster growth rate in dominant mode. We point out the condition for the growth anomaly in the adiabatic case is that information carried per particle exceeds a certain value $\delta I/\delta N>2\pi k_{\text{B}}\sqrt{(1+\mathcal{R})/(1-\mathcal{R})}$. We further construct several featured quantities to illustrate it, and formalize the anomaly-induced gravitational wave strain deformation.

    ↳ gr-qcastro-ph.COhep-phSCPMA(2025)·10 citations
33. 33*

    The functional generalization of the Boltzmann-Vlasov equation and its Gauge-like symmetry

    Giorgio Torrieri🇧🇷

    We argue that one can model deviations from the ensemble average in non-equilibrium statistical mechanics by promoting the Boltzmann equation to an equation in terms of {\em functionals} , representing possible candidates for phase space distributions inferred from a finite observed number of degrees of freedom. We find that, provided the collision term and the Vlasov drift term are both included, a gauge-like redundancy arises which does not go away even if the functional is narrow. We argue that this effect is linked to the gauge-like symmetry found in relativistic hydrodynamics \cite{bdnk} and that it could be part of the explanation for the apparent fluid-like behavior in small systems in hadronic collisions and other strongly-coupled small systems\cite{zajc}. When causality is omitted this problem can be look at via random matrix theory show, and we show that in such a case thermalization happens much more quickly than the Boltzmann equation would infer. We also sketch an algorithm to study this problem numerically

    ↳ cond-mat.stat-mechhep-phhep-thnucl-thSciPost Phys.(2024)·4 citations
34. 34*

    Effective Orientifolds from Broken Supersymmetry

    J. Mourad (APC, U. Paris Cité)🇫🇷 · A. Sagnotti (Scuola Normale Superiore and INFN, Pisa)🇮🇹

    We recently proposed a class of type IIB vacua that yield, at low energies, four--dimensional Minkowski spaces with broken supersymmetry and a constant string coupling. They are compactifications with an internal five-torus bearing a five--form flux $\Phi$ and warp factors depending on a single coordinate. The breaking of supersymmetry occurs when the internal space includes a finite interval. A probe-brane analysis revealed a gravitational repulsion and a charge attraction of equal magnitude from the left end of the interval, and a singularity at the other end. Here we complete the analysis revealing the presence, at one end, of an effective $O3$ of negative tension and positive five--form charge. We also determine the values of these quantities, and show that $T=-Q=\Phi$, and characterize the singularity present at the other end of the interval, which hosts an opposite charge. Finally, we discuss various forms of the gravity action in the presence of a boundary and identify a self--adjoint form for its fluctuations.

    ↳ hep-thgr-qchep-phJ.Phys.A(2024)·10 citations
35. 35*

    Sibyll${}^{★}$: ad-hoc modifications for an improved description of muon data in extensive air showers

    Felix Riehn🇪🇸 · Ralph Engel🇩🇪 · Anatoli Fedynitch🇹🇼

    Current simulations of air showers produced by ultra-high energy cosmic rays (UHECRs) do not satisfactorily describe recent experimental data, particularly when looking at the muonic shower component relative to the electromagnetic one. Discrepancies can be seen in both average values and on an individual shower-by-shower basis. It is thought that the muonic part of the air showers isn't accurately represented in simulations, despite various attempts to boost the number of muons within standard hadronic interaction physics. In this study, we investigate whether modifying the final state of events created with Sibyll~2.3d in air shower simulations can achieve a more consistent description of the muon content observed in experimental data. We create several scenarios where we separately increase the production of baryons, ${\rho }^0$, and strange particles to examine their impact on realistic air shower simulations. Our results suggest that these ad-hoc modifications can improve the simulations, providing a closer match to the observed muon content in air showers. One side-effect of the increased muon production in the considered model versions is a smaller difference in the predicted total muon numbers for proton and iron showers. However, more research is needed to find out whether any of these adjustments offers a realistic solution to the mismatches seen in data, and to identify the precise physical process causing these changes in the model. We hope that these modified model versions will also help to develop improved machine-learning analyses of air shower data and to estimate sys.{} uncertainties related to shortcomings of hadronic interaction models.

    ↳ astro-ph.HEhep-phPoS(2023)·6 citations
36. 36*

    Light Dark Matter in a Blazar-heated Universe

    Oindrila Ghosh🇸🇪 · Sankalan Bhattacharyya🇬🇧

    Prompt emissions from TeV blazars pair produce off the extragalactic background light and the highly energetic resulting pair beams then cascade through inverse Compton scattering to give rise to secondary gamma-rays. Such reprocessed cascade emission that can be associated with individual blazar sources has not been detected thus far. The absence of pair halos around these sources, along with the non-observation of isotropic gamma-ray background excess, seems to suggest that collective plasma effects, such as beam-plasma instabilities, can play a crucial role in alleviating this GeV-TeV tension by transferring the energy from the pair beams into the background plasma of the intergalactic medium (IGM). This has profound implications not only for TeV astrophysics, but also the strength of the intergalactic magnetic field and properties of dark matter (DM). A direct consequence of the instability losses and IGM heating is the modification of thermal history at late times, which suppresses structure formation particularly in baryonically underdense regions, potentially holding a clue towards resolving the small-scale crisis in cosmology. In a blazar-heated universe, the observation of dwarf galaxies and Lyman-$\alpha$ measurements present a favoured mass range for DM candidates such as light axion-like particles.

    ↳ astro-ph.COastro-ph.HEhep-phphysics.plasm-phPoS(2023)·2 citations
37. 37*

    CaloClouds II: Ultra-Fast Geometry-Independent Highly-Granular Calorimeter Simulation

    Erik Buhmann🇩🇪 · Frank Gaede🇩🇪 · Gregor Kasieczka🇩🇪 · Anatolii Korol🇩🇪 · William Korcari🇩🇪 · Katja Krüger🇩🇪 · Peter McKeown🇩🇪

    Fast simulation of the energy depositions in high-granular detectors is needed for future collider experiments with ever-increasing luminosities. Generative machine learning (ML) models have been shown to speed up and augment the traditional simulation chain in physics analysis. However, the majority of previous efforts were limited to models relying on fixed, regular detector readout geometries. A major advancement is the recently introduced CaloClouds model, a geometry-independent diffusion model, which generates calorimeter showers as point clouds for the electromagnetic calorimeter of the envisioned International Large Detector (ILD). In this work, we introduce CaloClouds II which features a number of key improvements. This includes continuous time score-based modelling, which allows for a 25-step sampling with comparable fidelity to CaloClouds while yielding a $6\times$ speed-up over Geant4 on a single CPU ($5\times$ over CaloClouds). We further distill the diffusion model into a consistency model allowing for accurate sampling in a single step and resulting in a $46\times$ ($37\times$ over CaloClouds) speed-up. This constitutes the first application of consistency distillation for the generation of calorimeter showers.

    ↳ physics.ins-detcs.LGhep-exhep-ph+1JINST(2024)·61 citations
38. 38*

    Thermodynamics of the parity-doublet model: Symmetric nuclear matter and the chiral transition

    Jürgen Eser🇫🇷 · Jean-Paul Blaizot🇫🇷

    We present a detailed discussion of the thermodynamics of the parity-doublet nucleon-meson model within a mean-field theory, at finite temperature and baryon-chemical potential, with special emphasis on the chiral transition at large baryon densities and vanishing temperature. We consider isospin-symmetric matter. We systematically compare the parity-doublet model to a related singlet model obtained by disregarding the chiral partner of the nucleon. After studying the ground state properties of nuclear matter, the nuclear liquid-gas transition, and the density modifications of the nucleon sigma term which govern the low-density regime, we give new insight into the underlying mechanisms of the zero-temperature chiral transition occurring at several times the nuclear saturation density. We show that the chiral transition is driven by a kind of symmetry energy that tends to equilibrate the populations of opposite parity baryons. This symmetry energy dictates the composition of matter at large baryon densities, once the phase space for the appearance of the negative-parity partner is opened. We furthermore highlight the characteristic role, within the thermodynamics, of the chiral-invariant mass of the parity-doublet model. We include the chiral limit into all of our discussions in order to provide a complete picture of the chiral transition.

    ↳ nucl-thhep-phPRC(2024)·21 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.