Tue·Nov 14, 2023Tuesday·November 14, 2023

1. 01*

   Effective 2HDM Yukawa Interactions and a Strong First-Order Electroweak Phase Transition

   Anisha🇬🇧 · Duarte Azevedo🇩🇪 · Lisa Biermann🇩🇪 · Christoph Englert🇬🇧 · Margarete Mühlleitner🇩🇪

   The top quark as the heaviest particle in the Standard Model (SM) defines an important mass scale for Higgs physics and the electroweak scale itself. It is therefore a well-motivated degree of freedom which could reveal the presence of new interactions beyond the SM. Correlating modifications of the top-Higgs interactions in the 2-Higgs-Doublet Model (2HDM), we analyse effective field theory deformations of these interactions from the point of view of a strong first-order electroweak phase transition (SFOEWPT). We show that such modifications are compatible with current Higgs data and that an SFOEWPT can be tantamount to a current overestimate of exotic Higgs searches' sensitivity at the LHC in $t\bar{t}$ and four top quark final states. We argue that these searches remain robust from the point of accidental signal-background interference so that the current experimental strategy might well lead to 2HDM-like discoveries in the near future.

   hep-phhep-exJHEP(2024)·18 citations
2. 02*

   Two-loop QED corrections to the scattering of four massive leptons

   Maximilian Delto🇩🇪 · Claude Duhr🇩🇪 · Lorenzo Tancredi🇩🇪 · Yu Jiao Zhu🇩🇪

   We study two-loop corrections to the scattering amplitude of four massive leptons in quantum electrodynamics. These amplitudes involve previously unknown elliptic Feynman integrals, which we compute analytically using the differential equation method. In doing so, we uncover the details of the elliptic geometry underlying this scattering amplitude and show how to exploit its properties to obtain compact, easy-to-evaluate series expansions that describe the scattering of four massive leptons in QED in the kinematical regions relevant for Bhabha and Møller scattering processes.

   hep-phPRL(2024)·35 citations
3. 03*

   Two-zero textures for Dirac Neutrinos

   Yessica Lenis🇨🇴 · R. Martinez-Ramirez🇲🇽 · Eduardo Peinado🇲🇽 · William A. Ponce🇨🇴

   We review the two-zero mass matrix textures approach for Dirac neutrinos with the most recent global fit in the oscillation parameters. We found that three of the 15 possible textures are compatible with current experimental data, while the remaining two-zero textures are ruled out. Two textures are consistent with the neutrino masses' normal hierarchy and are CP-conserving. At the same time, the other one is compatible with both mass orderings and allows for CP violation. We also present the correlations between the oscillation parameters for the allowed two-zero textures.

   hep-phCPC(2025)·2 citations
4. 04*

   Two Higgs doublet model fitting and $t\bar{t}b\bar{b}$ signal at the ILC

   Hieu Minh Tran🇻🇳 · Huong Thu Nguyen🇻🇳 · Yoshimasa Kurihara🇯🇵

   One of the most straightforward extensions of the standard model (SM) is having an additional Higgs doublet to the SM, namely the two Higgs doublet models(THDM). In the type-I model, an additional Higgs doublet is introduced that does not couple to any fermion via the Yukawa interaction in the original Lagrangian. Considering various theoretical and phenomenological constraints, we have found the best-fitted parameter set in the type-I model using the minimum ${\chi }^2$ method by scanning the model's parameter space. We show that this optimal parameter set can be tested by precisely analyzing the decay processes $D_s^{+}\to {\tau }^{+}{\nu }_{\tau }$, $D^{+}\to {\mu }^{+}{\nu }_{\mu }$, and $B^0\to K^{\ast }{\mu }^{+}{\mu }^{-}$. Moreover, the decay channels $h\to \gamma \gamma$ and $Z\gamma$ can be used to distinguish the model from the SM. For a direct search of the model at future colliders, we have proposed an investigation of the $e^{+}{e}^{-}\to t\bar{t}b\bar{b}$ process at the ILC to detect the new physics of the model. Considering the initial state radiation correction and applying appropriate background cuts, the calculation result of the scattering cross section shows that it is feasible to observe a clear and unique signal in the $t\bar{b}$ invariant mass distribution corresponding to the charged Higgs pair creations.

   hep-phPRD(2025)·2 citations
5. 05*

   Majorana Majoron and the Baryon Asymmetry of the Universe

   Wei Chao🇨🇳 · Ying-Quan Peng🇨🇳

   The spontaneous breaking of the global lepton number, an accidental symmetry in the Standard Model of particle physics, results in a massless goldstone boson, the Majoron, which can be taken as a cold dark matter candidate with properties similar to these of the axion. In this letter, we propose a novel mass generation mechanism for the Majoron via radiative corrections induced by the interaction of a tiny lepton-number-violating (LNV) Majorana mass term of right-handed neutrinos in the canonical seesaw mechanism. We show that this LNV Majorana mass term not only generates the mass of the Majoron but also leads to a non-zero initial velocity of the Majoron, which subsequently impacts on the relic abundance of the Majoron generated in the early universe via the misalignment mechanism. With the assistance of the Weinberg operator, the same initial velocity may also generate the lepton asymmetry, which is subsequently transported into the baryon asymmetry of the universe (BAU) via the weak sphaleron process. As a result, the neutrino masses, dark matter and the BAU can be addressed in this concise theoretical framework.

   hep-ph24 citations
6. 06*

   Long-range $S$-wave $D{D}^{\ast }$ interaction in covariant chiral effective field theory

   Qing-Yu Zhai🇨🇳 · Ming-Zhu Liu🇨🇳 · Jun-Xu Lu🇨🇳 · Li-Sheng Geng🇨🇳

   Motivated by the recent lattice QCD study of the $D{D}^{\ast }$ interaction at unphysical quark masses, we perform a theoretical study of the $D{D}^{\ast }$ interaction in covariant chiral effective field theory (ChEFT). In particular, we calculate the relevant leading-order two-pion exchange contributions. The results compare favorably with the lattice QCD results, supporting the conclusion that the intermediate-range $D{D}^{\ast }$ interaction is dominated by two-pion exchanges and the one-pion exchange contribution is absent. At a quantitative level, the covariant ChPT results agree better with the lattice QCD results than their non-relativistic counterparts, showing the relevance of relativistic corrections in the charm sector.

   hep-phhep-latPRD(2024)·6 citations
7. 07*

   Renormalization Group Summation at High Orders and Implications to the Determination of Some Standard Model Parameters

   M. S. A. Alam Khan🇮🇳

   We use renormalization group summed perturbation theory (RGSPT) to improve perturbation series in quantum chromodynamics in the determination of some of the standard model parameters.

   hep-phhep-exhep-lat0 citations
8. 08*

   Intrinsic Geometry of Collider Observations and Forman Ricci Curvature

   Jyotiranjan Beuria🇮🇳

   We study the global and local topological properties of multi-lepton patterns reconstructed at the detectors. We investigate the sensitivity of Forman Ricci curvature distributions and persistent homology features to kinematic cuts, integrated luminosity, and scales of maximum filtration. We find that these topological properties are efficient enough in discriminating the BSM scenarios from the SM background, particularly when the BSM scenarios possess a massive invisible particle. We also find that the topological properties exhibit a scaling behaviour with integrated luminosity. This exploratory study suggests that the topological features can potentially supplement the traditional cut-and-count analyses in search of new physics.

   hep-phhep-exhep-thmath-ph+1PRD(2024)·4 citations
9. 09*

   On production of heavy charged particles in $\gamma \gamma$ fusion at planned $pp$ colliders

   S. I. Godunov🇷🇺 · E. K. Karkaryan🇷🇺 · V. A. Novikov🇷🇺 · A. N. Rozanov🇫🇷 · M. I. Vysotsky🇷🇺 · E. V. Zhemchugov🇷🇺

   Production of heavy fermions in ultraperipheral collisions ($pp\to p+\gamma \gamma +p\to p+{\chi }^{+}{\chi }^{-}+p$) and the semiexclusive reaction ($pp\to p+\gamma {\gamma }^{\ast }+X\to p+{\chi }^{+}{\chi }^{-}+X$) is considered. Differential and total cross sections for the energies of the planned $pp$ colliders are presented.

   hep-phhep-exPisma Zh.Eksp.Teor.Fiz.(2024)·1 citation
10. 10*

    Jet Rotational Metrics

    Alexis Romero🇺🇸 · Daniel Whiteson🇺🇸

    Embedding symmetries in the architectures of deep neural networks can improve classification and network convergence in the context of jet substructure. These results hint at the existence of symmetries in jet energy depositions, such as rotational symmetry, arising from the physical features of the underlying processes. We introduce new jet observables, Jet Rotational Metrics (JRMs), which provide insights into the substructure of jets by comparing them to jets with perfect discrete rotational symmetry. We show that JRMs are formidable jet features, achieving good classification scores when used as inputs to deep neural networks. We also show that when used in combination with other jet observables, like N-subjettiness and EFPs, our features increase classification performance. The results suggest that JRMs may capture information not efficiently captured by the other observables, motivating the design of future jet observables for learning the underlying symmetries in the physical processes.

    hep-phhep-exJHEP(2024)·3 citations
11. 11*

    Stimulated decay of collapsing axion stars and fast radio bursts

    Haoran Di🇨🇳

    The radiation mechanism of fast radio bursts (FRBs) has been extensively studied but still remains elusive. In the search for dark matter candidates, the QCD axion and axionlike particles (ALPs) have emerged as prominent possibilities. These elusive particles can aggregate into dense structures called axion stars through Bose-Einstein condensation (BEC). Such axion stars could constitute a significant portion of the mysterious dark matter in the universe. When these axion stars grow beyond a critical mass, usually through processes like accretion or merging, they undergo a self-driven collapse. Traditionally, for spherically symmetric axion clumps, the interaction between axions and photons does not lead to parametric resonance, especially when the QCD axion-photon coupling is at standard levels. Nevertheless, our study indicates that even QCD axion stars with typical coupling values can trigger stimulated decay during their collapse, rather than producing relativistic axions through self-interactions. This process results in short radio bursts, with durations of around 0.1 seconds, and can be potentially observed using radio telescopes like FAST or SKA. Furthermore, we find that collapsing axion stars for ALPs with specific parameters may emit radio bursts lasting just milliseconds with a peak luminosity of $1.60\times 10^{42}erg/s$, matching the characteristics of the observed non-repeating FRBs.

    hep-phastro-ph.HEEPJC(2024)·13 citations
12. 12*

    Renormalon cancellation and linear power correction to threshold-like asymptotics of space-like parton correlators

    Yizhuang Liu🇵🇱 · Yushan Su🇺🇸

    In this paper, we show that the common hard kernel of double-log-type or threshold-type factorization for certain space-like parton correlators that arise in the context of lattice parton distributions, the heavy-light Sudakov hard kernel, has linear infrared (IR) renormalon. We explicitly demonstrate how this IR renormalon correlates with ultraviolet (UV) renormalons of next-to-leading power operators in two explicit examples: threshold asymptotics of space-like quark-bilinear coefficient functions and transverse momentum dependent (TMD) factorization of quasi wave function amplitude. Theoretically, the pattern of renormalon cancellation complies with general expectations to marginal asymptotics in the UV limit. Practically, this linear renormalon explains the slow convergence of imaginary parts observed in lattice extraction of the Collins-Soper kernel and signals the relevance of next-to-leading power contributions. Fully factorized, fully controlled threshold asymptotic expansion for space-like quark-bilinear coefficient functions in coordinate and moment space has also been proposed.

    hep-phhep-thJHEP(2024)·24 citations
13. 13*

    Soft photon theorem in QCD with massless quarks

    Yao Ma🇨🇭 · George Sterman🇺🇸 · Aniruddha Venkata🇺🇸

    Working to all orders in dimensionally-regularized QCD, we study the radiation of a photon whose energy is much lower than that of external partons, but much larger than the masses of some quarks. We argue that the conventional soft photon theorem receives corrections at leading power in the photon energy, associated with soft virtual loops of massless fermions. These additive corrections give an overall factor times the non-radiative amplitude that is infrared finite and real to all orders in ${\alpha }_s$. Based on recent calculations of the three-loop soft gluon current, we identify the lowest-order three-loop correction.

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

    Search for new physics in semileptonic decays of K and B as implied by the g-2 anomaly in FSM

    José Bordes🇪🇸 · Chan Hong-Mo🇬🇧 · Tsou Sheung Tsun🇬🇧

    The framed standard model (FSM), constructed to explain, with some success, why there should be 3 and apparently only 3 generations of quarks and leptons in nature falling into a hierarchical mass and mixing pattern, suggests also, among other things, a scalar boson U, with mass around 17 MeV and small couplings to quarks and leptons, which might explain the g-2 anomaly reported in experiment. The U arises in FSM initially as a state in the predicted `hidden sector' with mass around 17 MeV, which mixes with the standard model (SM) Higgs $h_W$, acquiring thereby a coupling to quarks and leptons and a mass just below 17 MeV. The initial purpose of the present paper is to check whether this proposal is compatible with experiment on semileptonic decays of Ks and Bs where the U can also appear. The answer to this we find is affirmative, in that the contribution of U to new physics as calculated in the FSM remains within the experimental bounds, but only if $m_U$ lies within a narrow range just below the unmixed mass. As a result from this, one has an estimate $m_U\sim 15-17$ MeV for the mass of $U$, and from some further considerations the estimate ${\Gamma }_U\sim 0.02$ eV for its width, both of which may be useful for an eventual search for it in experiment. And, if found, it will be, for the FSM, not just the discovery of a predicted new particle, but the opening of a window into a whole ``hidden sector" containing at least some, perhaps ven the bulk, of the dark matter in the universe.

    hep-phhep-exInt.J.Mod.Phys.A(2023)·1 citation
15. 15*

    Electroweak Baryogenesis and Higgs Physics

    Carlos E.M. Wagner🇺🇸

    We discuss the constraints on the Higgs sector coming from the requirement of the generation of the matter-antimatter asymmetry at the electroweak phase transition. These relate to both a strongly first order first transition, necessary for the preservation of the generated baryon asymmetry, as well as CP-violation, necessary for its generation. This scenario may lead to exotic decays of the Standard Model like Higgs, a deviation of the di-Higgs production cross section, or CP-violation in the Higgs sector. All these aspects are expected to be probed by the LHC as well as by electric dipole moment experiments, among others. Further phenomenological implications are discussed in this short review.

    hep-phLHEP(2023)·19 citations
16. 16*

    A QFT scalar toy model analogous to positronium and pion decays

    Milena Piotrowska🇵🇱 · Francesco Giacosa🇵🇱

    In the framework of a scalar QFT, we evaluate the decay of an initial massive state into two massless particles through a triangle-shaped diagram in which virtual fields propagate. Under certain conditions, the decaying state can be seen as a bound state, thus it is analogous to the neutral pion (quark-antiquark pair) and to the positronium (electron-positron pair), which decay into two photons. While the pion is a relativistic composite object, the positronium is a non-relativistic compound close to threshold. We exam similarities and differences between these two types of bound states.

    hep-phActa Phys.Polon.Supp.(2024)·2 citations
17. 17*

    High-precision scattering amplitudes for LHC phenomenology

    Piotr Bargiela🇬🇧

    In this work, we consider scattering amplitudes relevant for high-precision Large Hadron Collider (LHC) phenomenology. We analyse the general structure of amplitudes, and we review state-of-the-art methods for computing them. We discuss advantages and shortcomings of these methods, and we point out the bottlenecks in modern amplitude computations. As a practical illustration, we present frontier applications relevant for multi-loop multi-scale processes. We compute the helicity amplitudes for diphoton production in gluon fusion and photon+jet production in proton scattering in three-loop massless Quantum Chromodynamics (QCD). We have adopted a new projector-based prescription to compute helicity amplitudes in the 't Hooft-Veltman scheme. We also rederived the minimal set of independent Feynman integrals for this problem using the differential equations method, and we confirmed their intricate analytic properties. By employing modern methods for integral reduction, we provide the final results in a compact form, which is appropriate for efficient numerical evaluation. Beyond QCD, we have computed the two-loop mixed QCD-electroweak amplitudes for Z+jet production in proton scattering in light-quark-initiated channels, without closed fermion loops. This process provides important insight into the high-precision studies of the Standard Model, as well as into Dark Matter searches at the LHC. We have employed a numerical approach based on high-precision evaluation of Feynman integrals with the modern Auxiliary Mass Flow method. The obtained numerical results in all relevant partonic channels are evaluated on a two-dimensional grid appropriate for further phenomenological applications.

    hep-ph2 citations
18. 18*

    Exclusive Charmonium Production at the Electron-ion collider in China

    Xue Wang🇨🇳 · Xu Cao🇨🇳 · Aiqiang Guo🇨🇳 · Li Gong🇨🇳 · Xiao-Shen Kang🇨🇳 · Yu-Tie Liang🇨🇳 · Jia-Jun Wu🇨🇳 · Ya-Ping Xie🇨🇳

    We investigate the exclusive $J/\psi$ production at the future Electron-ion collider in China by utilizing the eSTARlight event generator. We model the cross-section and kinematics by fitting to the world data of $J/\psi$ photoproduction. Projected statistical uncertainties on $J/\psi$ production are based on the design of a central detector, which consists of a tracker and vertex subsystem. The precision of the pseudo-data allows us to probe the near-threshold mechanism, e.g. the re-scattering effect. The significance of the forward amplitudes is discussed as well. The design and optimization of the detector enhance the potential for exploring the near-threshold region and the realm of high four-momentum transfer squared, which is of particular interest on several physics topics..

    hep-phEPJC(2024)·9 citations
19. 19*

    Single-Spin Asymmetry of Neutrons in Polarized pA Collisions

    B.Z. Kopeliovich🇨🇱 · I.K. Potashnikova🇨🇱 · Ivan Schmidt🇨🇱

    Absorptive corrections, which are known to suppress proton-neutron transitions with a large fractional momentum z -> 1 in pp collisions, become dramatically strong on a nuclear target, and they push the partial cross sections of leading neutron production to the very periphery of the nucleus. The mechanism of the pion and axial vector a1-meson interference, which successfully explains the observed single-spin asymmetry in a polarized pp -> nX, is extended to the collisions of polarized protons with nuclei. When corrected for nuclear effects, it explains the observed single-spin azimuthal asymmetry of neutrons that is produced in inelastic events, which is where the nucleus violently breaks up. This single-spin asymmetry is found to be negative and nearly A-independent.

    hep-phnucl-thMDPI Physics(2023)·0 citations
20. 20*

    Probing Dirac Neutrino Properties with Dilepton Signature

    Wan-Lun Xu🇨🇳 · Zhi-Long Han🇨🇳 · Yi Jin🇨🇳 · Honglei Li🇨🇳 · Zongyang Lu🇨🇳 · Zhao-Xia Meng🇨🇳

    The neutrinophilic two Higgs doublet model is one of the simplest models to explain the origin of tiny Dirac neutrino masses. This model introduces a new Higgs doublet with eV scale VEV to naturally generate the tiny neutrino masses. Depending on the same Yukawa coupling, the neutrino oscillation patterns can be probed with the dilepton signature from the decay of charged scalar $H^{\pm }$. For example, the normal hierarchy predicts BR$(H^{+}\to e^{+}\nu )\ll$ BR$(H^{+}\to {\mu }^{+}\nu )\approx$ BR$(H^{+}\to {\tau }^{+}\nu )\simeq 0.5$ when the lightest neutrino mass is below 0.01 eV, while the inverted hierarchy predicts BR$(H^{+}\to e^{+}\nu )/2\simeq$ BR$(H^{+}\to {\mu }^{+}\nu )\simeq$ BR$(H^{+}\to {\tau }^{+}\nu )\simeq 0.25$. By precise measurement of BR$(H^{+}\to {\ell }^{+}\nu )$, we are hopefully to probe the lightest neutrino mass and the atmospheric mixing angle ${\theta }_{23}$. Through the detailed simulation of the dilepton signature and corresponding backgrounds, we find that the 3 TeV CLIC could discover $M_{H^{+}}\lesssim 1220$ GeV for NH and $M_{H^{+}}\lesssim 1280$ GeV for IH. Meanwhile, the future 100 TeV FCC-hh collider could probe $M_{H^{+}}\lesssim 1810$ GeV for NH and $M_{H^{+}}\lesssim 2060$ GeV for IH.

    hep-phhep-exEPJC(2024)·1 citation
21. 21*

    Form factors of decuplet baryons in a covariant quark-diquark approach

    JiaQi Wang🇨🇳 · Dongyan Fu🇨🇳 · Yubing Dong🇨🇳

    The electromagnetic and gravitational form factors of decuplet baryons are systematically studied with a covariant quark-diquark approach. The model parameters are firstly discussed and determined through comparison with the lattice calculation results integrally. Then, the electromagnetic properties of the systems including electromagnetic radii, magnetic moments, and electric-quadrupole moments are calculated. The obtained results are in agreement with experimental measurements and the results of other models. Finally, the gravitational form factors and the mechanical properties of the decuplet baryons, such as mass radii, energy densities, and spin distributions, are also calculated and discussed.

    hep-phEPJC(2024)·12 citations
22. 22*

    Quantum measurements in fundamental physics: a user's manual

    Jacob Beckey🇺🇸 · Daniel Carney🇺🇸 · Giacomo Marocco🇺🇸

    We give a systematic theoretical treatment of linear quantum detectors used in modern high energy physics experiments, including dark matter cavity haloscopes, gravitational wave detectors, and impulsive mechanical sensors. We show how to derive the coupling of signals of interest to these devices, and how to calculate noise spectra, signal-to-noise ratios, and detection sensitivities. We emphasize the role of quantum vacuum and thermal noise in these systems. Finally, we review ways in which advanced quantum techniques -- squeezing, non-demolition measurements, and entanglement -- can be or currently are used to enhance these searches.

    hep-phhep-exquant-phSciPost Phys.Rev.(2026)·25 citations
23. 23*

    Angularity in Higgs boson decays via $\mathbf{H}\to \mathbf{gg}$ at NNLL${}^{\prime }$ accuracy

    Jiawei Zhu🇨🇳 · Yujin Song🇨🇳 · Jun Gao🇨🇳 · Daekyoung Kang🇨🇳 · Tanmay Maji🇮🇳

    We present improved predictions of a class of event-shape distributions called angularity for a contribution from an effective operator $H\to gg$ in Higgs hadronic decay that suffers from large perturbative uncertainties. In the frame of Soft-Collinear Effective Theory, logarithmic terms of the distribution are resummed at NNLL${}^{\prime }$ accuracy, for which 2-loop constant of gluon-jet function for angularity is independently determined by a fit to fixed-order distribution at NLO corresponding to $\mathcal{O}({\alpha }_s^2)$ relative to the Born rate. Our determination shows reasonable agreement with the value in a thesis recently released. In the fit, we use an asymptotic form with a fractional power conjectured from recoil corrections at one-loop order and it improves the accuracy of determination in positive values of angularity parameter $a$. The resummed distribution is matched to the NLO fixed-order results to make our predictions valid at all angularity values. We also discuss the first moment and subtracted moment of angularity as a function of $a$ that allow to extract information on leading and subleading nonperturbative corrections associated with gluons.

    hep-phhep-exnucl-thCPC(2025)·7 citations
24. 24*

    Large $N_c$ QCD phase diagram at ${\mu }_B=0$

    T.D. Cohen🇺🇸 · L.Ya. Glozman🇦🇹

    Lattice studies suggest that at zero baryon chemical potential and increasing temperature there are three characteristic regimes in QCD that are connected by smooth analytical crossovers: a hadron gas regime at T < T_ch ~ 155 MeV, an intermediate regime, called stringy fluid, at T_ch < T < ~ 3 T_ch, and a quark-gluon plasma regime at higher temperatures. These regimes have been interpreted to reflect different approximate symmetries and effective degrees of freedom. In the hadron gas the effective degrees of freedom are hadrons and the approximate chiral symmetry of QCD is spontaneously broken. The intermediate regime has been interpreted as lacking spontaneous chiral symmetry breaking along with the emergence of new approximate symmetry, chiral spin symmetry, that is not a symmetry of the Dirac Lagrangian, but is a symmetry of the confining part of the QCD Lagrangian. While the high temperature regime is the usual quark-gluon plasma which is often considered to reflect "deconfinement" in some way. This paper explores the behavior of these regimes of QCD as the number of colors in the theory, N_c, gets large. In the large N_c limit the theory is center-symmetric and notions of confinement and deconfinement are unambiguous. The energy density is O(N_c^0) in the meson gas, O(N_c^1) in the intermediate regime and O(N_c^2) in the quark-gluon plasma regime. In the large N_c limit these regimes may become distinct phases separated by first order phase transitions. The intermediate phase has the peculiar feature that glueballs should exist and have properties that are unchanged from what is seen in the vacuum (up to 1/N_c corrections), while the ordinary dilute gas of mesons with broken chiral symmetry disappears and approximate chiral spin symmetry should emerge.

    hep-phhep-lathep-thnucl-thEPJA(2024)·32 citations
25. 25*

    General bubble expansion at strong coupling

    Jun-Chen Wang🇨🇳 · Zi-Yan Yuwen🇨🇳 · Yu-Shi Hao🇨🇳 · Shao-Jiang Wang🇨🇳

    The strongly coupled system like the quark-hadron transition (if it is of first order) is becoming an active play yard for the physics of cosmological first-order phase transitions. However, the traditional field theoretic approach to strongly coupled first-order phase transitions is of great challenge, driving recent efforts from holographic dual theories with explicit numerical simulations. These holographic numerical simulations have revealed an intriguing linear correlation between the phase pressure difference (pressure difference away from the wall) to the nonrelativistic terminal velocity of an expanding planar wall, which has been reproduced analytically alongside both cylindrical and spherical walls from perfect-fluid hydrodynamics in our previous study but only for a bag equation of state. We also found, in our previous study, a universal quadratic correlation between the wall pressure difference (pressure difference near the bubble wall) to the nonrelativistic terminal wall velocity regardless of wall geometries. In this paper, we will generalize these analytic relations between the phase/wall pressure difference and terminal wall velocity into a more realistic equation of state beyond the simple bag model, providing the most general predictions so far for future tests from holographic numerical simulations of strongly coupled first-order phase transitions

    hep-phastro-ph.COPRD(2024)·19 citations
26. 26*

    Hydrodynamical approach to chirality production during axion inflation

    E. V. Gorbar🇺🇦 · A. I. Momot🇺🇦 · O. O. Prikhodko🇺🇦 · O. M. Teslyk🇺🇦

    We study chirality production in the pseudoscalar inflation model of magnetogenesis taking into account the Schwinger effect and particle collisions in plasma in the relaxation time approximation. We consider the Schwinger production of one Dirac fermion species by an Abelian gauge field in two cases: (i) the fermion carries only the weak charge with respect to the U(1) group and (ii) it is also charged with respect to another strongly coupled gauge group. While the gradient-expansion formalism is employed for the description of the evolution of gauge field, plasma is described by hydrodynamical approach which allows us to determine the number, energy density, and chirality of produced fermions. It is found that while chirality production is very efficient for both, weakly and strongly interacting fermions, the resulting gauge field is typically stronger in the case of strongly interacting fermions due to suppression of the Schwinger conductivity by particle collisions.

    hep-phastro-ph.COhep-thPRD(2024)·10 citations
27. 27*

    Renormalization group improved photon impact factors and the high energy virtual photon scattering

    Dimitri Colferai🇮🇹 · Wanchen Li🇺🇸 · Anna M. Stasto🇺🇸

    We perform the renormalization group improved collinear resummation of the photon-gluon impact factors. We construct the resummed cross section for virtual photon-photon (${\gamma }^{\ast }{\gamma }^{\ast }$) scattering which incorporates the impact factors and BFKL gluon Green's function up to the next-to-leading logarithmic accuracy in energy. The impact factors include important kinematical effects which are responsible for the most singular poles in Mellin space at next-to-leading order. Further conditions on the resummed cross section are obtained by requiring the consistency with the collinear limits. Our analysis is consistent with previous impact factor calculations at NLO, apart from a new term proportional to $C_F$ that we find for the longitudinal polarization. Finally, we use the resummed cross section to compare with the LEP data on the ${\gamma }^{\ast }{\gamma }^{\ast }$ cross section and with previous calculations. The resummed result is lower than the leading logarithmic approximation but higher than the pure next-to-leading one, and is consistent with the experimental data.

    hep-phJHEP(2024)·3 citations
28. 28*

    Quark production and thermalization of the quark-gluon plasma

    Sergio Barrera Cabodevila🇪🇸 · Carlos A. Salgado🇪🇸 · Bin Wu🇪🇸

    We first assemble a full set of the Boltzmann Equation in Diffusion Approximation (BEDA) for studying thermalization/hydrodynamization as well as the production of massless quarks and antiquarks in out of equilibrium systems. In the BEDA, the time evolution of a generic system is characterized by the following space-time dependent quantities: the jet quenching parameter, the effective temperature, and two more for each quark flavor that describe the conversion between gluons and quarks/antiquarks via the $2\leftrightarrow 2$ processes. Out of the latter two quantities, an effective net quark chemical potential is defined, which equals the net quark chemical potential after thermal equilibration. We then study thermalization and the production of three flavors of massless quarks and antiquarks in spatially homogeneous systems initially filled only with gluons. A parametric understanding of thermalization and quark production is obtained for either initially very dense or dilute systems, which are complemented by detailed numerical simulations for intermediate values of initial gluon occupancy $f_0$. For a wide range of $f_0$, the final equilibration time is determined to be about one order of magnitude longer than that in the corresponding pure gluon systems. Moreover, during the final stage of the thermalization process for $f_0\ge 10^{-4}$, gluons are found to thermalize earlier than quarks and antiquarks, undergoing the top-down thermalization.

    hep-phnucl-thJHEP(2024)·14 citations
29. 29*

    Goldberger-Treiman relation and Wu-type experiment in the decuplet sector

    Magnus Bertilsson (Uppsala U.)🇸🇪 · Stefan Leupold (Uppsala U.)🇸🇪

    The leading-order chiral Lagrangian for the baryon octet and decuplet states coupled to Goldstone bosons and external sources contains six low-energy constants. Five of them are fairly well known from phenomenology, but the sixth one is practically unknown. This coupling constant provides the strength of the (p-wave) coupling of Goldstone bosons to decuplet states. Its size and even sign are under debate. Quark model and QCD for a large number of colors provide predictions, but some recent phenomenological analyses suggest even an opposite sign for the Delta-pion coupling. The Goldberger-Treiman relation connects this coupling constant to the axial charge of the Delta baryon. This suggests a Wu-type experiment to determine the unknown low-energy constant. While this is not feasible in the Delta sector because of the large hadronic width of the Delta, there is a flavor symmetry related process that is accessible: the weak semileptonic decay of the Omega baryon to a spin 3/2 cascade baryon. A broad research program is suggested that can pin down at least the rough size and the sign of the last unknown low-energy constant of the leading-order Lagrangian. It encompasses experimental measurements, in particular the forward-backward asymmetry of the semileptonic decay, together with a determination of the quark-mass dependences using lattice QCD for the narrow decuplet states and chiral perturbation theory to extrapolate to the Delta sector. Besides discussing the strategy of the research program, the present work provides a feasibility check based on a simple leading-order calculation.

    hep-phhep-latnucl-thPRD(2024)·6 citations
30. 30*

    A novel phenomenological approach to total charm cross section measurements at the LHC

    Yewon Yang🇩🇪 · Achim Geiser🇩🇪

    Measuring the total charm cross section is important for the comparison to theoretical predictions of the highest precision available for charm today, which are completely known up to NNLO QCD for the total inclusive cross sections. These are also independent of charm fragmentation, while practical measurements of charm hadrons in a fiducial phase space are not. Recently the LHC experiments have reported non-universality of charm fragmentation, which shows that e.g. charm baryon-to-meson ratios are not universal in different collision systems, and that the related production fractions also depend on transverse momentum. This breaks the charm fragmentation universality that was assumed until recently for the extrapolation of experimental measurements to the full total charm cross section phase space. A proposal is made how to address this non-universality in a data driven way without the need to implement any particular non-universal fragmentation model. As a practical example, this method is applied to the extrapolation of published LHC measurements of $D^0$ production at $\sqrt{s}=5$ TeV to the corresponding total charm cross section, which fully accounts for charm fragmentation non-universality for the first time. The result, $8.43_{-1.16}^{+1.05}(\text{total})$ mb, differs substantially from the one assuming charm fragmentation universality, but still compares well to theoretical QCD predictions up to NNLO.

    hep-phPoS(2024)·7 citations
31. 31*

    Gauged Global Strings

    Xuce Niu🇺🇸 · Wei Xue🇺🇸 · Fengwei Yang🇺🇸

    We investigate the string solutions and cosmological implications of the gauge $\mathrm{U}(1{)}_{\mathrm{Z}}\times$ global $\mathrm{U}(1{)}_{\mathrm{PQ}}$ model. With two hierarchical symmetry-breaking scales, the model exhibits three distinct string solutions: a conventional global string, a global string with a heavy core, and a gauge string as a bound state of the two global strings. This model reveals rich phenomenological implications in cosmology. During the evolution of the universe, these three types of strings can form a Y-junction configuration. Intriguingly, when incorporating this model with the QCD axion framework, the heavy-core global strings emit more axion particles compared to conventional axion cosmic strings due to their higher tension. This radiation significantly enhances the QCD axion dark matter abundance, thereby opening up the QCD axion mass window. Consequently, axions with masses exceeding $\sim 10^{-5}\mathrm{eV}$ have the potential to constitute the whole dark matter abundance. Furthermore, in contrast to conventional gauge strings, the gauge strings in this model exhibit a distinctive behavior by radiating axions.

    hep-phastro-ph.COhep-thJHEP(2024)·15 citations
32. 32*

    Isolating perturbative QCD splittings in heavy-ion collisions

    Leticia Cunqueiro🇮🇹 · Daniel Pablos🇮🇹 · Alba Soto-Ontoso🇨🇭 · Martin Spousta🇨🇿 · Adam Takacs🇳🇴 · Marta Verweij🇳🇱

    We define a new strategy to scan jet substructure in heavy-ion collisions. The scope is multifold: (i) test the dominance of vacuum jet dynamics at early times, (ii) capture the transition from coherent to incoherent jet energy loss, and (iii) study elastic scatterings in the medium, which are either hard and perturbative or soft and responsible for jet thermalisation. To achieve that, we analyse the angular distribution of the hardest splitting, ${\theta }_{\mathrm{hard}}$, above a transverse momentum scale, $k_t^{\min }$, in high-$p_t$ jets. Sufficiently high values of $k_t^{\min }$ target the regime in which the observable is uniquely determined by vacuum-like splittings and energy loss, leaving the jet substructure unmodified compared to proton-proton collisions. Decreasing $k_t^{\min }$ enhances the sensitivity to the relation between energy loss and the intra-jet structure and, in particular, to observe signatures of colour decoherence at small angles. At wider angles it also becomes sensitive to hard elastic scatterings with the medium and, therefore, the perturbative regime of medium response. Choosing $k_t^{\min }\approx 0$ leads to order one effects of non-perturbative origin such as hadronisation and, potentially, soft scatterings responsible for jet thermalisation. We perform a comprehensive analysis of this observable with three state-of-the-art jet-quenching Monte Carlo event generators. Our study paves the way for defining jet observables in heavy-ion collisions dominated by perturbative QCD and thus calculable from first principles.

    hep-phhep-exnucl-exnucl-thPRD(2024)·28 citations
33. 33*

    Probing the CP Structure of the Top Quark Yukawa at the Future Muon Collider

    Morgan E. Cassidy🇺🇸 · Zhongtian Dong🇺🇸 · Kyoungchul Kong🇺🇸 · Ian M. Lewis🇺🇸 · Yanzhe Zhang🇺🇸 · Ya-Juan Zheng🇺🇸

    We study the top-Higgs coupling with a CP violating phase $\xi$ at a future multi-TeV muon collider. We focus on processes that are directly sensitive to the top quark Yukawa coupling: $t\bar{t}h$, $tbh\mu \nu$, and $t\bar{t}h\nu \bar{\nu }$ with $h\to b\bar{b}$ and semileptonic top decays. At different energies, different processes dominate the cross section, providing complementary information. At and above an energy of $\mathcal{O}(10)$ TeV, vector boson fusion processes dominate. As we show, in the Standard Model there is destructive interference in the vector boson fusion processes $t\bar{t}h\nu \bar{\nu }$ and $tbh\mu \nu$ between the top quark Yukawa and Higgs-gauge boson couplings. A CP-violating phase changes this interference, and the cross section measurement is very sensitive to the size of the CP-violating angle. Although we find that the cross sections are measured to $\mathcal{O}(50\%)$ statistical uncertainty at $1\sigma$, a 10 and 30 TeV muon collider can bound the CP-violating angle $|\xi |\lesssim 9.0^{\circ }$ and $|\xi |\lesssim 5.4^{\circ }$, respectively. However, cross section measurements are insensitive to the sign of the CP-violating angle. To determine that the coupling is truly CP violating, observables sensitive to CP-violation must be measured. We find in the $t\bar{t}h$ process the azimuthal angle between the $t+\bar{t}$ plane and the initial state muon+Higgs plane shows good discrimination for $\xi =\pm 0.1\pi$. For the $tbh\mu \nu$ and $t\bar{t}h\nu \bar{\nu }$ processes, the operator proportional to $\left({\vec{p}}_{\mu }\times {\vec{p}}_h\right)\cdot {\vec{p}}_t$ is sensitive to the sign of CP phase $\xi$. From these observables, we construct asymmetry parameters that show good distinction between different values and signs of the CP violating angle.

    hep-phJHEP(2024)·19 citations
34. 34*

    Coherent Self-Interactions of Dark Matter in the Bullet Cluster

    Zachary Bogorad🇺🇸 · Peter W. Graham🇺🇸 · Harikrishnan Ramani🇺🇸

    Many models of dark matter include self-interactions beyond gravity. A variety of astrophysical observations have previously been used to place limits on the strength of such self-interactions. However, previous works have generally focused either on short-range interactions resulting in individual dark matter particles scattering from one another, or on effectively infinite-range interactions which sum over entire dark matter halos. In this work, we focus on the intermediate regime: forces with range much larger than dark matter particles' inter-particle spacing, but still shorter than the length scales of known halos. We show that gradients in the dark matter density of such halos would still lead to observable effects. We focus primarily on effects in the Bullet Cluster, where finite-range forces would lead either to a modification of the collision velocity of the cluster or to a separation of the dark matter and the galaxies of each cluster after the collision. We also consider constraints from the binding of ultrafaint dwarf galaxy halos, and from gravitational lensing of the Abell 370 cluster. Taken together, these observations allow us to set the strongest constraints on dark matter self-interactions over many orders of magnitude in range below $\sim 10$ kpc, surpassing existing limits by orders of magnitude throughout.

    hep-phastro-ph.COastro-ph.GAJCAP(2025)·17 citations
35. 35*

    Safe but Incalculable: Energy-weighting is not all you need

    Samuel Bright-Thonney🇺🇸 · Benjamin Nachman🇺🇸 · Jesse Thaler🇺🇸

    Infrared and collinear (IRC) safety has long been used a proxy for robustness when developing new jet substructure observables. This guiding philosophy has been carried into the deep learning era, where IRC-safe neural networks have been used for many jet studies. For graph-based neural networks, the most straightforward way to achieve IRC safety is to weight particle inputs by their energies. However, energy-weighting by itself does not guarantee that perturbative calculations of machine-learned observables will enjoy small non-perturbative corrections. In this paper, we demonstrate the sensitivity of IRC-safe networks to non-perturbative effects, by training an energy flow network (EFN) to maximize its sensitivity to hadronization. We then show how to construct Lipschitz Energy Flow Networks (L-EFNs), which are both IRC safe and relatively insensitive to non-perturbative corrections. We demonstrate the performance of L-EFNs on generated samples of quark and gluon jets, and showcase fascinating differences between the learned latent representations of EFNs and L-EFNs.

    hep-phhep-exPRD(2024)·10 citations
36. 36*

    Constraints on Dark Matter from Dynamical Heating of Stars in Ultrafaint Dwarfs. Part 1: MACHOs and Primordial Black Holes

    Peter W. Graham🇺🇸 · Harikrishnan Ramani🇺🇸

    We place limits on dark matter made up of compact objects significantly heavier than a solar mass, such as MACHOs or primordial black holes (PBHs). In galaxies, the gas of such objects is generally hotter than the gas of stars and will thus heat the gas of stars even through purely gravitational interactions. Ultrafaint dwarf galaxies (UFDs) maximize this effect. Observations of the half-light radius in UFDs thus place limits on MACHO dark matter. We build upon previous constraints with an improved heating rate calculation including both direct and tidal heating, and consideration of the heavier mass range above $10^4{M}_{\odot }$. Additionally we find that MACHOs may lose energy and migrate in to the center of the UFD, increasing the heat transfer to the stars. UFDs can constrain MACHO dark matter with masses between about $10M_{\odot }$ and $10^8{M}_{\odot }$ and these are the strongest constraints over most of this range.

    hep-phastro-ph.COastro-ph.GAhep-thPRD(2024)·38 citations
37. 37*

    Probing positivity at the LHC with exclusive photon-fusion processes

    Jiayin Gu🇨🇳 · Chi Shu🇨🇳

    By tagging one or two intact protons in the forward direction, it is possible to select and measure exclusive photon-fusion processes at the LHC. The same processes can also be measured in heavy ion collisions, and are often denoted as ultraperipheral collisions (UPC) processes. Such measurements open up the possibility of probing certain dimension-8 operators and their positivity bounds at the LHC. As a demonstration, we perform a phenomenological study on the $\gamma \gamma \to {\ell }^{+}{\ell }^{-}$ processes, and find out that the measurements of this process at the HL-LHC provide reaches on a set of dimension-8 operator coefficients that are comparable to the ones at future lepton colliders. We also point out that the $\gamma q\to \gamma q$ process could potentially have better reaches on similar types of operators due to its larger cross section, but a more detailed experimental study is need to estimate the signal and background rates of this process. The validity of effective field theory (EFT) and the robustness of the positivity interpretation are also discussed.

    hep-phhep-exJHEP(2024)·9 citations
38. 38*

    Primordial Black Holes and Wormholes from Domain Wall Networks

    Yann Gouttenoire🇮🇱 · Edoardo Vitagliano🇮🇱

    Domain walls (DWs) are topological defects originating from phase transitions in the early universe. In the presence of an energy imbalance between distinct vacua, enclosed DW cavities shrink until the entire network disappears. By studying the dynamics of thin-shell bubbles in General Relativity, we demonstrate that closed DWs with sizes exceeding the cosmic horizon tend to annihilate later than the average. This delayed annihilation allows for the formation of large overdensities, which, upon entering the Hubble horizon, eventually collapse to form Primordial Black Holes (PBHs). We rely on 3D percolation theory to calculate the number density of these late-annihilating DWs, enabling us to infer the abundance of PBHs. A key insight from our study is that DW networks with the potential to emit observable Gravitational Waves are also likely to yield detectable PBHs. Additionally, we find that wormholes connected to baby-universes can be produced and conclude on the possibility to generate a multiverse.

    hep-phastro-ph.COgr-qchep-thPRD(2024)·55 citations
39. 39*

    $\mathcal{P},\mathcal{T}$-Odd Weak Neutral Current Interactions in the TlF Molecule

    Timo Fleig🇫🇷

    Leptoquark models may explain deviations from the Standard Model observed in decay processes involving heavy quarks at high-energy colliders. Such models give rise to low-energy parity- and time-reversal-violating phenomena in atoms and molecules. One of the leading effects among these phenomena is the nucleon-electron tensor-pseudotensor interaction when the low-energy experimental probe uses a quantum state of an atom or molecule predominantly characterized by closed electron shells. In the present paper the molecular interaction constant for the nucleon-electron tensor-pseudotensor interaction in the thallium-fluoride molecule -- used as such a sensitive probe by the CeNTREX collaboration [Quantum Sci. Technol., 6:044007, 2021] -- is calculated employing highly-correlated relativistic many-body theory. Accounting for up to quintuple excitations in the wavefunction expansion the final result is $W_T(\text{Tl)}=-6.25\pm 0.31$[$10^{-13}{⟨\Sigma ⟩}_A$ a.u.] Interelectron correlation effects on the tensor-pseudotensor interaction are studied for the first time in a molecule, and a common framework for the calculation of such effects in atoms and molecules is presented.

    ↳ physics.atom-phhep-phPRA(2024)·5 citations
40. 40*

    Quantization of Second Order Fermions

    Rodolfo Ferro-Hernández🇩🇪 · Julio Olmos🇲🇽 · Eduardo Peinado🇲🇽 · Carlos A. Vaquera-Araujo🇲🇽

    The quantization of a massive spin $1/2$ field that satisfies the Klein-Gordon equation is studied. The framework is consistent, provided it is formulated as a pseudo-hermitian quantum field theory by the redefinition of the field dual and the identification of an operator that modifies the inner product of states in Hilbert space to preserve a real energy spectrum and unitary evolution. Since the fermion field has mass dimension one, the theory admits renormalizable fermion self-interactions.

    ↳ hep-thhep-phPRD(2024)·7 citations
41. 41*

    Search for Highly-Ionizing Particles in pp Collisions During LHC Run-2 Using the Full MoEDAL Detector

    MoEDAL Collaboration

    This search for Magnetic Monopoles (MMs) and High Electric Charge Objects (HECOs) with spins 0, 1/2 and 1, uses for the first time the full MoEDAL detector, exposed to 6.6 fb^-1 proton-proton collisions at 13 TeV. The results are interpreted in terms of Drell-Yan and photon-fusion pair production. Mass limits on direct production of MMs of up to 10 Dirac magnetic charges and HECOs with electric charge in the range 5e to 350e were achieved. The charge limits placed on MM and HECO production are currently the strongest in the world. MoEDAL is the only LHC experiment capable of being directly calibrated for highly-ionizing particles using heavy ions and with a detector system dedicated to definitively measuring magnetic charge.

    ↳ hep-exhep-phPRL(2025)·28 citations
42. 42*

    TURBO: The Swiss Knife of Auto-Encoders

    Guillaume Quétant🇨🇭 · Yury Belousov · Vitaliy Kinakh · Slava Voloshynovskiy🇨🇭

    We present a novel information-theoretic framework, termed as TURBO, designed to systematically analyse and generalise auto-encoding methods. We start by examining the principles of information bottleneck and bottleneck-based networks in the auto-encoding setting and identifying their inherent limitations, which become more prominent for data with multiple relevant, physics-related representations. The TURBO framework is then introduced, providing a comprehensive derivation of its core concept consisting of the maximisation of mutual information between various data representations expressed in two directions reflecting the information flows. We illustrate that numerous prevalent neural network models are encompassed within this framework. The paper underscores the insufficiency of the information bottleneck concept in elucidating all such models, thereby establishing TURBO as a preferable theoretical reference. The introduction of TURBO contributes to a richer understanding of data representation and the structure of neural network models, enabling more efficient and versatile applications.

    ↳ cs.LGcs.CRcs.IThep-ph+1Entropy(2023)·2 citations
43. 43*

    Relativistic corrections to the static potential from generalized Wilson loops at finite flow time

    Michael Eichberg🇩🇪 · Marc Wagner🇩🇪

    We present results from an ongoing project concerned with the computation of $\mathcal{O}(1/m_Q)$ and $\mathcal{O}(1/m_Q^2)$ relativistic corrections to the static potential. These corrections are extracted from Wilson loops with two chromo-field insertions. We use gradient flow, which allows to renormalize the inserted fields and leads to a significantly improved signal-to-noise ratio, providing access to loops with large spatial and temporal extents.

    ↳ hep-lathep-phPoS(2024)·4 citations
44. 44*

    The topological susceptibility slope ${\chi }^{\prime }$ of the pure-gauge SU(3) Yang-Mills theory

    Claudio Bonanno🇪🇸

    We determine the pure-gauge $\mathrm{SU}(3)$ topological susceptibility slope ${\chi }^{\prime }$, related to the next-to-leading-order term of the momentum expansion of the topological charge density 2-point correlator, from numerical lattice Monte Carlo simulations. Our strategy consists in performing a double-limit extrapolation: first we take the continuum limit at fixed smoothing radius, then we take the zero-smoothing-radius limit. Our final result is ${\chi }^{\prime }=[17.1(2.1)\mathrm{MeV}{]}^2$. We also discuss a theoretical argument to predict its value in the large-$N$ limit, which turns out to be remarkably close to the obtained $N=3$ lattice result.

    ↳ hep-lathep-phhep-thJHEP(2024)·16 citations
45. 45*

    Dilepton production at next-to-leading order and intermediate invariant-mass observables

    Jessica Churchill🇨🇦 · Lipei Du🇨🇦 · Charles Gale🇨🇦 · Greg Jackson🇫🇷 · Sangyong Jeon🇨🇦

    The thermal QCD dilepton production rate is calculated at next-to-leading order in the strong coupling and at finite baryon chemical potential. The two-loop virtual photon self-energy is evaluated using finite temperature field theory and combined consistently with the self-energy in the Landau-Pomeranchuk-Migdal regime. We present new results for a dense baryonic plasma. The rates are then integrated using (3+1)-dimensional fluid-dynamical simulations calibrated to reproduce hadronic experimental results obtained at RHIC at energies ranging from those of the Beam Energy Scan to $\sqrt{s_{{}_{\mathrm{NN}}}}=200$ GeV. We elaborate on the ability for dileptons to relay information about the plasma baryonic content and temperature.

    ↳ nucl-thhep-exhep-phnucl-exPRC(2024)·40 citations
46. 46*

    Pion-sigma meson vortices in rotating systems

    D. N. Voskresensky🇷🇺

    Possibilities of the formation of the pion-sigma meson field vortices in a rotating empty vessel (in vacuum) and in the pion-sigma Bose-Einstein condensates at a dynamically fixed particle number are studied within the linear $\sigma$ model at zero temperature. The charged $\sigma {\pi }^{\pm }$ and neutral $\sigma {\pi }^0$ complex field ansatze (models 1 and 2) are studied. First it is analysed, which of these configurations is energetically favorable in case of the system at rest. Then conditions are found, at which a chiral field storm can arise in a rotating empty vessel. In the model 1 an important role played by the electric field is demonstrated. Its appearance may allow for formation of a supervortex (vortex with a large angular momentum) in case of the empty vessel rotating with an overcritical angular velocity. Influence of magnetic field is also studied. Field configurations in presence and absence of the meson self-interaction are found in both models. Then it is shown that description of the charged (in model 1) and neutral (in model 2) rotating pion-sigma Bose-Einstein condensates is analogous to that for the Bose-Einstein condensates in cold atomic gases. Various field configurations such as vortex lines, rings and spirals are discussed. Conditions for existence of the rigid-body rotation of the vortex lattice are then analysed. Observational effects for vortex fields in rotating vessels, energetic heavy-ion collisions and in rotating superheavy nuclei and nuclearites are discussed.

    ↳ nucl-thcond-mat.supr-conhep-phPRD(2024)·7 citations
47. 47*

    Virtual Photons Shed Light on the Early Temperature of Dense QCD Matter

    Jessica Churchill🇨🇦 · Lipei Du🇨🇦 · Charles Gale🇨🇦 · Greg Jackson🇺🇸 · Sangyong Jeon🇨🇦

    Dileptons produced during heavy-ion collisions represent a unique probe of the QCD phase diagram, and convey information about the state of the strongly interacting system at the moment their preceding off-shell photon is created. In this study, we compute thermal dilepton yields from Au+Au collisions performed at different beam energies, employing a (3+1)-dimensional dynamic framework combined with emission rates accurate at next-to-leading order in perturbation theory and which include baryon chemical potential dependencies. By comparing the effective temperature extracted from the thermal dilepton invariant mass spectrum with the average temperature of the fluid, we offer a robust quantitative validation of dileptons as effective probe of the early quark-gluon plasma stage.

    ↳ nucl-thhep-exhep-phnucl-exPRL(2024)·38 citations
48. 48*

    Phase Transition Study meets Machine Learning

    Yu-Gang Ma🇨🇳 · Long-Gang Pang🇨🇳 · Rui Wang🇨🇳 · Kai Zhou🇩🇪

    In recent years, machine learning (ML) techniques have emerged as powerful tools for studying many-body complex systems, and encompassing phase transitions in various domains of physics. This mini review provides a concise yet comprehensive examination of the advancements achieved in applying ML to investigate phase transitions, with a primary focus on those involved in nuclear matter studies.

    ↳ nucl-thhep-phChin.Phys.Lett.(2023)·57 citations
49. 49*

    Consistent first order action functional for gauge theories

    Priidik Gallagher🇪🇪 · Tomi S. Koivisto🇪🇪 · Luca Marzola🇪🇪 · Ludovic Varrin🇵🇱 · Tom Zlosnik🇵🇱

    A novel first order action principle has been proposed as the possible foundation for a more fundamental theory of General Relativity and the Standard Model. It is shown in this article that the proposal consistently incorporates gravity and matter fields, and guides to a new and robust path towards unification of fundamental interactions.

    ↳ hep-thgr-qchep-phPRD(2024)·9 citations
50. 50*

    Backreaction of axion-SU(2) dynamics during inflation

    Oksana Iarygina🇸🇪 · Evangelos I. Sfakianakis🇪🇸 · Ramkishor Sharma🇸🇪 · Axel Brandenburg🇸🇪

    We consider the effects of backreaction on axion-SU(2) dynamics during inflation. We use the linear evolution equations for the gauge field modes and compute their backreaction on the background quantities numerically using the Hartree approximation. We show that the spectator chromo-natural inflation attractor is unstable when back-reaction becomes important. Working within the constraints of the linear mode equations, we find a new dynamical attractor solution for the axion field and the vacuum expectation value of the gauge field, where the latter has an opposite sign with respect to the chromo-natural inflation solution. Our findings are of particular interest to the phenomenology of axion-SU(2) inflation, as they demonstrate the instability of the usual trajectory due to large backreaction effects. The viable parameter space of the model becomes significantly altered, provided future non-Abelian lattice simulations confirm the existence of the new dynamical attractor. In addition, the backreaction effects lead to characteristic oscillatory features in the primordial gravitational wave background that are potentially detectable with upcoming gravitational wave detectors.

    ↳ astro-ph.COhep-phhep-thJCAP(2024)·36 citations
51. 51*

    Chiral Symmetry Restoration and the Ultraquantum limit of Axionic Charge Density Waves in Weyl Semimetals

    Joan Bernabeu🇪🇸 · Alberto Cortijo🇪🇸

    A new mechanism for chiral symmetry restoration at extreme high magnetic fields is proposed in the context of the Magnetic Catalysis scenario in Weyl Semimetals. Contrary to previous proposals, here we show that, at very large magnetic fields, the transverse velocity of the axion field, the phase mode of the chiral condensate $⟨\bar{\Psi }\Psi ⟩$, becomes effectively one-dimensional and its fluctuations destroy a possible nonzero value of this fermionic condensate. We also show that, despite of the $U(1)$ chiral symmetry not being broken at extremely large magnetic fields, the spectrum of the system is comprised by a well defined gapless bosonic excitation, connected to the axion mode, and a correlated insulating fermionic liquid that is neutral to $U(1)$ chiral transformations. When the theory is supplemented with the inclusion of dynamical electromagnetic fields, the chiral symmetry is broken again, and the conventional scenario of magnetic catalysis can be recovered.

    ↳ cond-mat.str-elhep-phhep-thJHEP(2024)·4 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.