Tue·Nov 28, 2023Tuesday·November 28, 2023

1. 01*

   Pion and kaon electromagnetic and gravitational form factors

   Yin-Zhen Xu🇪🇸 · Minghui Ding🇩🇪 · Khépani Raya🇪🇸 · Craig D. Roberts🇨🇳 · José Rodríguez-Quintero🇪🇸 · Sebastian M. Schmidt🇩🇪

   A unified set of predictions for pion and kaon elastic electromagnetic and gravitational form factors is obtained using a symmetry-preserving truncation of each relevant quantum field equation. A key part of the study is a description of salient aspects of the dressed graviton + quark vertices. The calculations reveal that each meson's mass radius is smaller than its charge radius, matching available empirical inferences; and meson core pressures are commensurate with those in neutron stars. The analysis described herein paves the way for a direct calculation of nucleon gravitational form factors.

   hep-phhep-exhep-latnucl-ex+1EPJC(2024)·60 citations
2. 02*

   Electroweak corrections to Higgs boson production via Z Z fusion at the future LHeC

   Hanying Xiong🇨🇳 · Hongsheng Hou🇨🇳 · Zhuoni Qian🇨🇳 · Qingjun Xu🇨🇳 · Bowen Wang🇨🇳

   An important mechanism for production of the Higgs boson at the prospective Large Hadron-electron Collider (LHeC) is via neutral current (NC) weak boson fusion (WBF) processes. Aside from its role in measurements of Higgs couplings within the standard model, this production mode is particularly useful in searchings of Higgs decays into invisble particles in various models for the Higg portal dark matter. In this work we compute the electroweak corrections for the NC WBF at the LHeC up to the 1-loop level. For a center-of-mass energy of 1.98 TeV, the magnitudes of the relative corrections for the total cross section at next-to-leading (NLO) order are respectively 8% and 17%, in the two renormalization schemes we use. The NLO terms also distort various distributions (notably, those for Higgs and electron observables) computed at the leading order. Along with our previous treatment of the charge current processes, this paper completes the calulation of the NLO EW effects for the dominant Higgs production modes at the LHeC.

   hep-phPRD(2024)·2 citations
3. 03*

   Uncovering Secret Neutrino Interactions at Tau Neutrino Experiments

   Pouya Bakhti🇰🇷 · Meshkat Rajaee🇰🇷 · Seodong Shin🇰🇷

   We investigate the potential of future tau neutrino experiments for identifying the ${\nu }_{\tau }$ appearance in probing secret neutrino interactions. The reference experiments include the DUNE far detector utilizing the atmospheric data, which is for the first time in probing the secret interactions, the Forward Liquid Argon Experiment (FLArE100) detector at the Forward Physics Facility (FPF), and emulsion detector experiments such as SND@LHC, AdvSND, FASER$\nu$2, and SND@SHiP. For concreteness, we consider a reference scenario in which the hidden interactions among the neutrinos are mediated by a single light gauge boson $Z^{\prime }$ with a mass at most below the sub-GeV scale and an interaction strength $g_{\alpha \beta }$ between the active neutrinos. We confirm that these experiments have the capability to significantly enhance the current sensitivities on $g_{\alpha \beta }$ for $m_{Z^{\prime }}\lesssim 500$ MeV due to the production of high energy neutrinos and excellent ability to detect tau neutrinos. Our analysis highlights the crucial role of downward-going DUNE atmospheric data in the search for secret neutrino interactions because of the rejection of backgrounds dominated in the upward-going events. Specifically, 10 years of DUNE atmospheric data can provide the best sensitivities on $g_{\alpha \beta }$ which is about two orders of magnitude improvement. In addition, the beam-based experiments such as FLArE100 and FASER$\nu$2 can improve the current constraint on $g_{e\tau }$ and $g_{\mu \tau }$ by more than an order of magnitude after the full running of the high luminosity LHC with the integrated luminosity of 3 ab${}^{-1}$. For $g_{e\mu }$ and $g_{ee}$ the SHiP experiment can play the most important role in the high energy region of $E>few100$ MeV.

   hep-phhep-exPRD(2024)·5 citations
4. 04*

   Precise QCD predictions for W-boson production in association with a charm jet

   A. Gehrmann-De Ridder🇨🇭 · T. Gehrmann🇨🇭 · E. W. N. Glover🇬🇧 · A. Huss🇨🇭 · A. Rodriguez Garcia🇨🇭 · G. Stagnitto🇮🇹

   The production of a $W$-boson with a charm quark jet provides a highly sensitive probe of the strange quark distribution in the proton. Employing a novel flavour dressing procedure to define charm quark jets, we compute $W$+charm-jet production up to next-to-next-to-leading order (NNLO) in QCD. We study the perturbative stability of production cross sections with same-sign and opposite-sign charge combinations for the $W$ boson and the charm jet. A detailed breakdown according to different partonic initial states allows us to identify particularly suitable observables for the study of the quark parton distributions of different flavours.

   hep-phhep-exEPJC(2024)·9 citations
5. 05*

   Our Dark Matter Stopping in the Earth

   H.B. Nielsen (Niels Bohr Institut)🇩🇰 · Colin D. Froggatt (Glasgow University)🇬🇧

   We have worked for some time on a model for dark matter, in which dark matter consists of small bubbles of a new speculated type of vacuum, which are pumped up by some ordinary matter such as diamond, so as to resist the pressure of the domain wall separating the two vacua. Here we put forward thoughts on, how such macroscopic pearls would have their surrounding dust cleaned off passing through the atmosphere and the Earth, and what their distribution would be as a function of the depth of their stopping point and the distribution of the radiation emitted from them. In our model we assume that they radiate 3.5 keV electrons and photons, after having been excited during their passage into the Earth. The purpose of such an estimation of the radiation distribution is to explain the truly mysterious fact that, among all the underground experiments seeking dark matter colliding with the Earth material, only the DAMA-LIBRA experiment has seen any evidence of dark matter. This is an experiment based on solid NaI scintillators and is rather deep at 1400 m. It is our point that we can arrange the main radiation to appear in the relatively deep DAMA- LIBRA site, and explain that the dark matter pearls cannot stop in a fluid, such as xenon in the xenon based experiments.

   hep-phastro-ph.HE2 citations
6. 06*

   Combining chromomagnetic and four-fermion operators with leading SMEFT operators for $gg\to hh$ at NLO QCD

   Gudrun Heinrich🇩🇪 · Jannis Lang🇩🇪

   We present the calculation of the contribtuions from the chromomagnetic and four-top-quark-operators within Standard Model Effective Field Theory (SMEFT) to Higgs boson pair production in gluon fusion, combined with full NLO QCD corrections. We study the effects of these operators on the total cross section and the invariant mass distribution of the Higgs-boson pair, at $\sqrt{s}=13.6$ TeV. These subleading operators are implemented in the generator ggHH_SMEFT, in the same Powheg-Box-V2 framework as the leading operators, such that their effects can be easily studied in a unified setup.

   hep-phJHEP(2024)·33 citations
7. 07*

   Why do we not see the radiative decays of Ds1(2536)?

   Alex Bondar🇷🇺

   This article is an attempt to extract information about the radiative width of the Ds1(2536)->Ds gamma decay from the results available in the literature and to discuss the consequences of such an attempt.

   hep-phhep-ex1 citation
8. 08*

   CP violation in lepton-number-conserving processes through heavy Majorana neutrinos at future lepton colliders

   Zhe Wang🇨🇳 · Xing-Hua Yang🇨🇳 · Xin-Yi Zhang🇨🇳

   Small neutrino masses confirmed in the neutrino oscillation experiments indicate the need for new physics beyond the standard model. Seesaw mechanism is an interesting way to extend the standard model for explaining the neutrino masses. In a low-scale type-I seesaw mechanism, the tiny masses of neutrinos can be explained by heavy Majorana neutrino masses. Heavy Majorana neutrinos can lead to lepton-number-violating processes and the induced CP violation can contribute to the baryon asymmetry in the Universe. Heavy Majorana neutrinos can also lead to lepton-number-conserving processes and in this paper, we study the CP violation in lepton-number-conserving processes through heavy Majorana neutrinos at future lepton colliders. New possible observations of CP violation can also be connected to evidences of new physics beyond the standard model.

   hep-phPLB(2024)·8 citations
9. 09*

   Spin polarization and spin alignment from quantum kinetic theory with self-energy corrections

   Shuo Fang🇨🇳 · Shi Pu🇨🇳 · Di-Lun Yang🇹🇼

   We derive the quantum kinetic theory for massive fermions with collision terms and self-energy corrections based on quantum field theory. We adopt an effective power counting scheme with $\hslash$ expansion to obtain the leading-order perturbative solutions of the vector and axial Wigner functions and the corresponding kinetic equations. We observe that both the onshell relation and the structure of Wigner functions, along with the kinetic equations, are modified due to the presence of self-energies and their space-time gradients. We further apply our formalism to investigate the spin polarization phenomena in relativistic heavy ion collisions and derive the modification to the spin polarization spectrum of massive quarks. We find that the gradient of vector self-energy plays a similar role to the background electromagnetic fields, which induces a more dominant contribution than the collisional effects by a naive power counting in the gradient expansion and weak coupling. Our findings could further modify the spin polarization of strange quarks and spin alignment of $\varphi$ mesons beyond local thermal equilibrium.

   hep-phhep-thnucl-thPRD(2024)·38 citations
10. 10*

    Radiative decays \$D^*_{(s)}\to D_{(s)}\gamma$ in covariant confined quark model

    Chien-Thang Tran🇻🇳 · Mikhail A. Ivanov🇷🇺 · Pietro Santorelli🇮🇹 · Quang-Chau Vo🇻🇳

    Radiative decays $D_{(s)}^{\ast }\to D_{(s)}\gamma$ are revisited in light of new experimental data from the \textit{BABAR} and BESIII collaborations. The radiative couplings $g_{D^{\ast }D\gamma }$ encoding nonperturbative QCD effects are calculated in the framework of the covariant confined quark model developed by us. We compare our results with other theoretical studies and experimental data. The couplings (in ${\text{GeV}}^{-1}$) $|g_{D^{\ast +}{D}^{+}\gamma }|=0.45(9)$ and $|g_{D^{\ast 0}{D}^0\gamma }|=1.72(34)$ calculated in our model agree with the corresponding experimental data $|g_{D^{\ast +}{D}^{+}\gamma }|=0.47(7)$ and $|g_{D^{\ast 0}{D}^0\gamma }|=1.77(16)$. The most interesting case is the decay $D_s^{\ast }\to D_s\gamma$, for which a recent prediction based on light-cone sum rules at next-to-leading order $|g_{D_s^{\ast }{D}_s\gamma }|=0.60(19)$ deviates from the first (and only to date) lattice QCD result $|g_{D_s^{\ast }{D}_s\gamma }|=0.11(2)$ at nearly $3\sigma$. Our calculation yields $|g_{D_s^{\ast }{D}_s\gamma }|=0.29(6)$, which falls somehow between the two mentioned results, although it is larger than those predicted in other studies using quark models or QCD sum rules.

    hep-phhep-exCPC(2024)·15 citations
11. 11*

    Non-perturbative quantum Yang--Mills at finite temperature beyond lattice: a Dyson--Schwinger approach

    Marco Frasca🇮🇹 · Anish Ghoshal🇵🇱 · Stefan Groote🇪🇪

    Using a Dyson--Schwinger approach, we perform an analysis of the non-trivial ground state of thermal $SU(N)$ Yang--Mills theory in the non-perturbative regime where chiral symmetry is dynamically broken by a mass gap. Basic thermodynamic observables such as energy density and pressure are derived analytically, using Jacobi elliptic functions. The results are compared with lattice results. Good agreement is found at low temperatures, providing a viable scenario of a gas of massive glue states populating higher levels of the spectrum of the theory. At high temperatures a scenario without glue states consistent with a massive scalar field is observed, showing an interesting agreement with lattice data. The possibility is discussed that the results derived in this analysis open up a novel pathway beyond lattice to precision studies of phase transitions with false vacuum and cosmological relics that depend on the equations of state in strong coupled gauge theories of the type of Quantum Chromodynamics (QCD).

    hep-phgr-qchep-lathep-thSymmetry(2025)·3 citations
12. 12*

    Optimize the event selection strategy to study the anomalous quartic gauge couplings at muon colliders using the support vector machine and quantum support vector machine

    Shuai Zhang🇨🇳 · Yu-Chen Guo🇨🇳 · Ji-Chong Yang🇨🇳

    The search of the new physics~(NP) beyond the Standard Model is one of the most important topics in current high energy physics. With the increasing luminosities at the colliders, the search for NP signals requires the analysis of more and more data, and the efficiency in data processing becomes particularly important. As a machine learning algorithm, support vector machine~(SVM) is expected to to be useful in the search of NP. Meanwhile, the quantum computing has the potential to offer huge advantages when dealing with large amounts of data, which suggests that quantum SVM~(QSVM) is a potential tool in future phenomenological studies of the NP. How to use SVM and QSVM to optimize event selection strategies to search for NP signals are studied in this paper. Taking the tri-photon process at a muon collider as an example, it can be shown that the event selection strategies optimized by the SVM and QSVM are effective in the search of the dimension-8 operators contributing to the anomalous quartic gauge couplings.

    hep-phEPJC(2024)·9 citations
13. 13*

    Charged Higgs decay to $W^{\pm }$ and heavy neutral Higgs decaying into ${\tau }^{+}{\tau }^{-}$ in Georgi Machacek Model at LHC

    Swagata Ghosh🇮🇳

    The CMS collaboration at the Large Hadron Collider (LHC) searched for a charged Higgs boson, in the mass range of 300 to 700 GeV, decaying into a $W^{\pm }$ boson and a heavy neutral Higgs boson of mass $200$ GeV, which successively decays into a pair of tau leptons, in proton-proton collisions at $\sqrt{s}=13$ TeV. In this letter, focusing on the Georgi-Machacek (GM) model, I discuss the parameter space, allowed by the theoretical and experimental constraints, for which the limits on this process obtained by the CMS can be accommodated. The study in this letter also shows that, for the choice of the parameters, the decay of the charged Higgs boson $H_3^{\pm }$ to $W^{\pm }$ and a heavy neutral Higgs boson H is preferred over the decay to any gauge boson and any other neutral or charged Higgs bosons. I also present the values of production cross-section times branching ratio for the decay of H to a pair of b-quarks at $\sqrt{s}=14$ TeV.

    hep-phLHEP(2024)·6 citations
14. 14*

    Automated Ring-Diagram Framework for Classifying CP Invariants

    Neda Darvishi🇬🇧 · Yining Wang🇨🇳 · Jiang-Hao Yu🇨🇳

    In this study, we introduce a transformative, automated framework for classifying basis invariants in generic field theories. Utilising a novel ring-diagram methodology accompanied by the well-known Cayley-Hamilton theorem, our approach uniquely enables the identification of basic invariants and their CP-property characterisation. Critically, our framework also unveils previously concealed attributes of established techniques reliant on the Hilbert-Poincaré series and its associated Plethystic logarithm. This paradigm shift has broad implications for the deeper understanding and more accurate classification of CP invariants in generic field theories.

    hep-phhep-thPRD(2023)·5 citations
15. 15*

    Detection prospects of long-lived quirk pairs at the LHC far detectors

    Jinmian Li🇨🇳 · Xufei Liao🇨🇳 · Jian Ni🇨🇳 · Junle Pei🇨🇳

    We examine the sensitivity reaches of several LHC far detectors, such as FASER2, MATHUSLA, ANUBIS, SND@LHC, and FACET, to five simplified quirk scenarios. We include the next-to-leading order QCD corrections in our simulation of quirk events, which enhance the total production rate and increase the fraction of events in the forward direction for most cases. We calculate the time scales for the quirk pair to lose energy through radiations and for the quirk pair annihilation. Our results show that these far detectors can offer promising probes to the quirk scenario, complementing the searches at the main detectors. Especially, FACET and FASER2 detectors can surpass the majority of searches conducted at the LHC main detector, with the exception of the HSCP search, for the color-neutral quirk $\mathcal{E}$.

    hep-phPRD(2024)·9 citations
16. 16*

    Hunting for $X_b$ via hidden bottomonium decays $X_b\to \pi \pi {\chi }_{bJ}$

    Zhao-Sai Jia🇨🇳 · Zhen-Hua Zhang🇨🇳 · Wen-Hua Qin🇨🇳 · Gang Li🇨🇳

    In this work, we investigate the isospin breaking decay $X_b\to {\pi }^0{\chi }_{bJ}$ and the isospin conserved decay $X_b\to \pi \pi {\chi }_{bJ}$, where $X_b$ is taken to be the heavy quark flavor symmetry counterpart of $X(3872)$ in the bottomonium sector as a $B^{\ast }\bar{B}$ molecule candidate. Since the mass of this state may be far below the $B{\bar{B}}^{\ast }$ threshold and the mass difference between the neutral and charged bottom meson is small compared to the binding energy of the $X_b$, the isospin-violating decay channel $X_b\to {\pi }^0{\chi }_{bJ}$ would be highly suppressed. The calculated partial width of $X_b\to \pi \pi {\chi }_{b1}$ is found to be about tens of $\mathrm{keVs}$, $1\sim 2$ order(s) of magnitude larger than those of $X_b\to \pi \pi {\chi }_{b2}$ and $X_b\to \pi \pi {\chi }_{b0}$. Taking into account the fact that the total width of $X_b$ may be smaller than a few MeV like $X(3872)$, the calculated branching ratios $X_b\to \pi \pi {\chi }_{b1}$ may reach to orders of $10^{-2}$, which makes it a possible channel for the experimental searching of the $X_b$.

    hep-phPRD(2024)·7 citations
17. 17*

    Bounds on ALP-Mediated Dark Matter Models from Celestial Objects

    Tanech Klangburam🇹🇭 · Chakrit Pongkitivanichkul🇹🇭

    We have studied the signals from axion-like particles (ALPs) as dark matter mediators from celestial objects such as neutron stars, brown dwarfs or white dwarfs. We consider the accumulation of dark matter inside the celestial objects using the multiscatter capturing process. The production of ALP from the dark matter annihilation can escape the celestial object and decay into gamma-rays and neutrinos before reaching the Earth. We investigate our model using gamma-ray observations from Fermi and H.E.S.S. and neutrino observations from IceCube and ANTARES. The effective Lagrangian approach allows us to place constraints on the ALP-photon and ALP-fermion couplings. In the gamma-ray channel, our results are able to rule out the existence of ALP with mass up to $\sim \mathcal{O}(10)$ GeV. On the other hand, the neutrino observations can be used to probe a higher mass range with ALP mass up to $\sim \mathcal{O}(100)$ GeV.

    hep-phastro-ph.HEJHEP(2024)·4 citations
18. 18*

    Semirelativistic study on the semileptonic decays of $B_q$ mesons to orbital excited heavy Tensors

    Wen-Yuan Ke🇨🇳 · Su-Yan Pei🇨🇳 · Tianhong Wang🇨🇳 · Guo-Li Wang🇨🇳

    Based on the method of solving the complete Salpeter equation, we study the semileptonic decays of a $0^{-}$ heavy meson to $1P$, $2P$, or $3P$ heavy tensor mesons, $B_q\to (\bar{c}q)(nP){\ell }^{+}{\nu }_{\ell }$ $(q=u,d,s,c;n=1,2,3)$. The obtained branching ratio of $\mathcal{B}(B\to D_2^{\star }(2460){\ell }^{+}{\nu }_{\ell })$ agrees with the experimental data. We predict $\mathcal{B}\left(B_s^0\to D_{s2}^{\star -}(1P){\ell }^{+}{\nu }_{\ell }\right)$$=$$3.76\times 10^{-3}$ and $\mathcal{B}\left(B_c^{+}\to {\chi }_{c2}(1P){\ell }^{+}{\nu }_{\ell }\right)$$=$$1.82\times 10^{-3}$. The branching ratios of decays to $2P$ and $3P$ final states are found to be very small. The ratios $\mathcal{R}({\bar{D}}_2^{\star 0})=0.045$, $\mathcal{R}(D_{s2}^{\star })=0.048$ and $\mathcal{R}({\chi }_{c2})=0.059$ are also obtained. This study focuses on the contribution of relativistic corrections. The wave function of the pseudoscalar includes non-relativistic $S$-wave and relativistic $P$-wave. While for a tensor, it contains non-relativistic $P$-wave and relativistic $P$, $D$ and $F$ waves in its wave function. We find the individual contributions of relativistic partial waves are significant in the decay $B\to D_2^{\star }(2460){\ell }^{+}{\nu }_{\ell }$, but the overall contribution of the relativistic effect is $24.4\%$, which is small due to cancellation. Similarly, for the decay $B_s^0\to D_{s2}^{\star -}(1P){\ell }^{+}{\nu }_{\ell }$, the contribution of the relativistic effect is $28.8\%$. While for $B_c^{+}\to {\chi }_{c2}(1P){\ell }^{+}{\nu }_{\ell }$, the individual contributions of relativistic partial waves and the overall relativistic correction are both small, the later of which is $22.1\%$.

    hep-phhep-exPRD(2024)·0 citations
19. 19*

    Impact of shell model interactions on nuclear responses to WIMP elastic scattering

    Raghda Abdel Khaleq🇦🇺 · Giorgio Busoni🇦🇺 · Cedric Simenel🇦🇺 · Andrew E. Stuchbery🇦🇺

    Background: Nuclear recoil from scattering with weakly interacting massive particles (WIMPs) is a signature searched for in direct detection of dark matter. The underlying WIMP-nucleon interactions could be spin and/or orbital angular momentum (in)dependent. Evaluation of nuclear recoil rates through these interactions requires accounting for nuclear structure, e.g., through shell model calculations. Purpose: To evaluate nuclear response functions induced by these interactions for ${}^{19}$F, ${}^{23}$Na, ${}^{28,29,30}$Si, ${}^{40}$Ar, ${}^{70,72,73,74,76}$Ge, ${}^{127}$I, and ${}^{128,129,130,131,132,134,136}$Xe nuclei that are relevant to current direct detection experiments, and to estimate their sensitivity to shell model interactions. Methods: Shell model calculations are performed with the NuShellX solver. Nuclear response functions from non-relativistic effective field theory (NREFT) are evaluated and integrated over transferred momentum for quantitative comparisons. Results: Although the standard spin independent response is barely sensitive to the structure of the nuclei, large variations with the shell model interaction are often observed for the other channels. Conclusions: Significant uncertainties may arise from the nuclear components of WIMP-nucleus scattering amplitudes due to nuclear structure theory and modelling. These uncertainties should be accounted for in analyses of direct detection experiments.

    hep-phnucl-thPRD(2024)·7 citations
20. 20*

    Relative contributions of cross-even and cross-odd parts to the spin dependent elastic hadron scattering amplitudes at high energies

    O.V. Selyugin🇷🇺

    The form and energy dependence of different terms of the cross-even and cross-odd parts of the elastic nucleon-nucleon scattering amplitude is determined in the framework of the High Energy Generalize Structure (HEGS) model. In the framework of the HEGS model, using the electromagnetic and gravitomagnetic form factors, the differential cross sections in the Coulomb Nuclear Interference (CNI) region and at large momentum transfer are described well in a wide energy region simultaneously. It is shown that the cross-even part includes the soft pomeron growing like Log(s)2 and an additional term with a large slope and with Log(s) growth. The cross-odd part includes the maximal odderon term and an additional oscillation term Log(s) growth. It is shown that both additional terms are proportional to charge distributions, but the maximal odderon term is proportional to matter distributions

    hep-phhep-exPhys.Atom.Nucl.(2024)·0 citations
21. 21*

    Chiral hydrodynamics of expanding systems

    Nora Weickgenannt🇫🇷 · Jean-Paul Blaizot🇫🇷

    We obtain equations of motion for the boost-invariant expansion of a system of chiral particles. Our analysis is based on the Boltzmann equation for left- and right-handed massless particles in the relaxation time approximation. We assume Bjorken symmetry, but allow for parity breaking. We generalize the relaxation time approximation to take into account the so-called side-jump effect, but we show that the ensuing correction happens to vanish for Bjorken symmetry. After expressing the conserved currents in terms of chiral moments, we derive equations of motion for these moments from the Boltzmann equation. After a suitable truncation, these equations allow us to study the transition from the early-time collisionless regime to the hydrodynamic regime at late time, where the parity-violating chiral moments decay exponentially. The truncation that we use for the parity-violating moments is shown to be identical to Israel-Stewart's 14-moment approximation. Our final set of equations can be used to calculate the energy-momentum tensor, vector-, and axial-vector currents with chiral degrees of freedom for possible applications in heavy-ion collisions.

    hep-phnucl-thPRD(2024)·23 citations
22. 22*

    Structure of $cc\bar{c}\bar{c}$ tetraquarks and interpretation of LHC states

    Muhammad Naeem Anwar🇬🇧 · Timothy J. Burns🇬🇧

    Motivated by recent experimental evidence for apparent $cc\bar{c}\bar{c}$ states at LHCb, CMS and ATLAS, we consider how the mass spectrum and decays of such states can be used to discriminate among their possible theoretical interpretations, with a particular focus on identifying whether quarks or diquarks are the most relevant degrees of freedom. Our preferred scenario is that $X(6600)$ and its apparent partner state $X(6400)$ are the tensor $(2^{++})$ and scalar $(0^{++})$ states of an S-wave multiplet of $cc\bar{c}\bar{c}$ states. Using tetraquark mass relations which are independent of (or only weakly dependent on) model parameters, we give predictions for the masses of additional partner states with axial and scalar quantum numbers. Additionally, we give predictions for relations among decay branching fractions to $J/\psi J/\psi$, $J/\psi {\eta }_c$, ${\eta }_c{\eta }_c$ and $D^{(\ast )}{\bar{D}}^{(\ast )}$ channels. The scenario we consider is consistent with existing experimental data on $J/\psi J/\psi$, and our predictions for partner states and their decays can be confronted with future experimental data, to discriminate between quark and diquark models.

    hep-phhep-exhep-latPRD(2024)·12 citations
23. 23*

    H-COUP Version 3: A program for one-loop corrected decays of any Higgs bosons in non-minimal Higgs models

    Masashi Aiko🇯🇵 · Shinya Kanemura🇯🇵 · Mariko Kikuchi🇯🇵 · Kodai Sakurai🇯🇵 · Kei Yagyu🇯🇵

    The H-COUP program is provided as a package of Fortran codes, which can compute observables related to Higgs bosons including radiative corrections in various extended Higgs sectors. We give a manual for the latest version of H-COUP (H-COUP_3.0), in which decay rates and branching ratios of all the Higgs bosons can be calculated at one-loop level in EW and Higgs interactions with QCD corrections in the Higgs singlet model, four types of the two Higgs doublet model with a softly-broken $Z_2$ symmetry, and the inert doublet model. The previous version (H-COUP_2.0) can evaluate those only for the standard model like Higgs boson with the mass of 125 GeV ($h$). In H-COUP_3.0, renormalized quantities are computed based on the gauge independent on-shell renormalization scheme. The source code of H-COUP_3.0 can be downloaded via the following link: \url{http://www-het.phys.sci.osaka-u.ac.jp/~hcoup}. By using H-COUP_3.0, we can compare the precise measurements of the properties of $h$ and direct searches for additional Higgs bosons with their predictions at one-loop level, by which we can reconstruct the structure of the Higgs sector.

    hep-phComput.Phys.Commun.(2024)·24 citations
24. 24*

    Quantum kinetic approach to the Schwinger production of scalar particles in an expanding universe

    Anastasia V. Lysenko🇺🇦 · Oleksandr O. Sobol🇩🇪

    We study the Schwinger pair creation of scalar charged particles by a homogeneous electric field in an expanding universe in the quantum kinetic approach. We introduce an adiabatic vacuum for the scalar field based on the Wentzel-Kramers-Brillouin solution to the mode equation in conformal time and apply the formalism of Bogolyubov coefficients to derive a system of quantum Vlasov equations for three real kinetic functions. Compared to the analogous system of equations previously reported in the literature, the new one has two advantages. First, its solutions exhibit a faster decrease at large momenta which makes it more suitable for numerical computations. Second, it predicts no particle creation in the case of conformally coupled massless scalar field in the vanishing electric field, i.e., it respects the conformal symmetry of the system. We identify the ultraviolet divergences in the electric current and energy-momentum tensor of produced particles and introduce the corresponding counterterms in order to cancel them.

    hep-phastro-ph.COGen.Rel.Grav.(2024)·7 citations
25. 25*

    Extraction of the microscopic properties of quasi-particles using deep neural networks

    Olga Soloveva🇩🇪 · Andrea Palermo🇺🇸 · Elena Bratkovskaya🇩🇪

    We use deep neural networks (DNN) to obtain the microscopic characteristics of partons in terms of dynamical degrees of freedom on the basis of an off-shell quasiparticle description. We aim to infer masses and widths of quasi-gluons, up/down, and strange quarks using constraints on the macroscopic thermodynamic observables obtained by the first-principles calculations lattice QCD. In this work, we use 3 independent dimensionless thermodynamic observables from lQCD for minimization. First, we train our DNN using the DQPM (Dynamical QuasiParticle Model) Ansatz for the masses and widths. Furthermore, we use the DNN capabilities to generalize this Ansatz, to evaluate which quasiparticle characteristics are desirable to describe different thermodynamic functions simultaneously. To evaluate consistently the microscopic properties obtained by the DNN in the case of off-shell quarks and gluons, we compute transport coefficients using the spectral function within Kubo-Zubarev formalism in different setups. In particular, we make a comprehensive comparison in the case of the dimensionless ratios of shear viscosity over entropy density $\eta /s$ and electric conductivity over temperature ${\sigma }_Q/T$, which provide additional constraints for the parameter generalization of the considered models.

    hep-phnucl-thPRC(2024)·10 citations
26. 26*

    Phenomenology of the flavor symmetric scoto-seesaw model with dark matter and TM${}_1$ mixing

    Joy Ganguly🇮🇳 · Janusz Gluza🇵🇱 · Biswajit Karmakar🇵🇱 · Satyabrata Mahapatra🇰🇷

    We propose a hybrid scoto-seesaw model based on the $A_4$ non-Abelian discrete flavor symmetry. Light neutrino masses come from the tree-level type-I seesaw mechanism and from the one-loop scotogenic contribution accommodating viable dark matter candidates responsible for observed relic abundance of dark matter (DM). Respectively, both these contributions restore the atmospheric and solar neutrino mass scales. With only one right-handed neutrino, the model features specific predictions with the normal ordering of light neutrino masses, the lightest neutrino being massless, and only one relevant CP Majorana phase. The flavor symmetric setup helps us to realize the TM${}_1$ mixing scheme with concrete correlations and constraints on the mixing angles and associated CP phases. The framework predicts the atmospheric mixing angle to be in the upper octant with specific ranges $0.531(0.580)\le {\sin }^2{\theta }_{23}\le 0.544(0.595)$ and the Dirac CP phase is restricted within the range $\pm (1.44-1.12)$ radian. The Majorana phase is also tightly constrained with a range of $0.82-0.95$ and $1.58-1.67$ radian, which is otherwise unconstrained from neutrino oscillations. Strict predictions on the Majorana phases also yield an accurate prediction for the effective mass parameter for neutrinoless double beta within the range of $1.61-3.85$ meV. The model offers a rich phenomenology regarding DM relic density and direct search constraints, and the fermionic DM scenario has been discussed in detail, estimating its possible connection with the neutrino sector. As an example of the model studies at colliders, the SM Higgs in the diphoton decay channel is examined. The model predicts strictly vanishing $\tau \to e\gamma$, $\tau \to 3e$ decays and testable signals by MEG-II and SINDRUM/Mu3e experiments for the $\mu \to e\gamma$ and $\mu \to 3e$ decays, respectively.

    hep-phPRD(2024)·13 citations
27. 27*

    Energy loss of a fast moving parton in Gribov-Zwanziger plasma

    Manas Debnath🇮🇳 · Ritesh Ghosh🇺🇸 · Mohammad Yousuf Jamal🇮🇳 · Manu Kurian🇺🇸 · Jai Prakash🇮🇳

    The Gribov-Zwanziger prescription applied within Yang-Mills theory is demonstrated to be an efficient method for refining the theory's infrared dynamics. We study the collisional energy loss experienced by a high-energetic test parton as it traverses through the Grivov plasma at finite temperature. To achieve this, we employ a semi-classical approach that considers the parton's energy loss while accounting for the back-reaction induced by the polarization effects due to its motion in the medium. The polarization tensor of the medium is estimated within a non-perturbative resummation considering the Gribov-Zwanziger approach. The modification of the gluon and ghost loops due to the presence of the Gribov parameter plays a vital role in our estimation. We observe that the non-perturbative interactions have a sizable effect on the parton energy loss. Further, we discuss the implications of our findings in the context of relativistic heavy-ion collisions.

    hep-phnucl-thPRD(2024)·16 citations
28. 28*

    NLO EW corrections to polarised W${}^{+}$W${}^{-}$ production and decay at the LHC

    Ansgar Denner🇩🇪 · Christoph Haitz🇩🇪 · Giovanni Pelliccioli🇩🇪

    In this letter we present results for next-to-leading-order electroweak corrections to doubly polarised W${}^{+}$W${}^{-}$ production at the LHC in the fully leptonic decay channel. We model the production and the decay of two polarised W bosons in the double-pole approximation, including factorisable real and virtual electroweak corrections, and separating polarisation states at amplitude level. We obtain integrated and differential predictions for polarised signals in a realistic fiducial setup.

    hep-phhep-exPLB(2024)·35 citations
29. 29*

    Top-philic ALP phenomenology at the LHC: the elusive mass-window

    Simone Blasi🇩🇪 · Fabio Maltoni🇧🇪 · Alberto Mariotti🇧🇪 · Ken Mimasu🇬🇧 · Davide Pagani🇮🇹 · Simone Tentori🇧🇪

    We study the LHC phenomenology of an Axion Like Particle (ALP) that couples only derivatively with the top quark at tree level. We inspect the radiatively induced couplings with the SM fermions and (gauge) bosons and the associated production and decay mechanisms of the ALP. We focus on the most challenging mass window that remains open for a top-philic ALP, i.e., the range between tens and hundreds of GeV. Not only ALP production processes but also virtual ALP contributions to final states with top quarks are considered in detail. We show how searches through resonant production, such as ALP production in association with a $t\bar{t}$ pair, are complementary to precision measurements of $t\bar{t}$ and $t\bar{t}t\bar{t}$ final states, the latter being competitive or even more powerful for a top-philic ALP in this mass window. Finally, we explore the scenario where the top-philic ALP acts as a mediator to a dark-matter sector, resulting in missing energy signatures at the LHC. We find that the LHC constraints from $t\bar{t}$, $t\bar{t}t\bar{t}$ and ALP + jet production, together with those from $t\bar{t}$ + ALP production, can already exclude a large fraction of the parameter space leading to the correct relic abundance.

    hep-phhep-exJHEP(2024)·41 citations
30. 30*

    Exploring CP violation in $H\to {\tau }^{+}{\tau }^{-}\gamma$

    Erlend Aakvaag🇳🇴 · Nikolai Fomin🇳🇴 · Anna Lipniacka🇳🇴 · Stefan Pokorski🇵🇱 · Janusz Rosiek🇵🇱 · Dibyakrupa Sahoo🇵🇱

    We propose a method of measuring the CP-odd part of the Yukawa interaction of Higgs boson and $\tau$ leptons by observing the forward-backward asymmetry in the decay $H\to {\tau }^{+}{\tau }^{-}\gamma$. The source of such asymmetry is the interference of the CP-even loop-level contribution coming from $H\to Z\gamma \to {\tau }^{+}{\tau }^{-}\gamma$ decay channel with the contribution from tree-level CP-odd Yukawa interaction. We find that the CP violating effect is maximum when the invariant mass of the ${\tau }^{+}{\tau }^{-}$ pair is equal to the mass of the $Z$ boson. We propose and utilise various Dalitz plot asymmetries to quantify the maximal size of the asymmetry and perform Monte Carlo simulations to study the feasibility of measuring it in the high luminosity phase of the Large Hadron Collider (HL-LHC).

    hep-phEPJC(2024)·3 citations
31. 31*

    Region analysis of QED massive fermion form factor

    Jaco ter Hoeve🇳🇱 · Eric Laenen🇳🇱 · Coenraad Marinissen🇳🇱 · Leonardo Vernazza🇮🇹 · Guoxing Wang🇫🇷

    We perform an analysis of the one- and two-loop massive quark form factor in QED in a region expansion, up to next-to-leading power in the quark mass. This yields an extensive set of regional integrals, categorized into three topologies, against which factorization theorems at next-to-leading power could be tested. Our analysis reveals a number of subtle aspects involving rapidity regulators, as well as additional regions that manifest themselves only beyond one loop, at the level of single diagrams, but which cancel in the form factor.

    hep-phJHEP(2024)·17 citations
32. 32*

    Finite Bubble Statistics Constrain Late Cosmological Phase Transitions

    Gilly Elor🇺🇸 · Ryusuke Jinno🇯🇵 · Soubhik Kumar🇺🇸 · Robert McGehee🇺🇸 · Yuhsin Tsai🇺🇸

    We consider first order cosmological phase transitions (PT) happening at late times, below Standard Model (SM) temperatures $T_{\mathrm{PT}}\lesssim$ GeV. The inherently stochastic nature of bubble nucleation and the finite number of bubbles associated with a late-time PT lead to superhorizon fluctuations in the PT completion time. We compute how such fluctuations eventually source curvature fluctuations with universal properties, independent of the microphysics of the PT dynamics. Using Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) measurements, we constrain the energy released in a dark-sector PT. For 0.1 eV $\lesssim T_{\mathrm{PT}}\lesssim$ keV this constraint is stronger than both the current bound from additional neutrino species $\Delta N_{\mathrm{eff}}$, and in some cases, even CMB-S4 projections. Future measurements of CMB spectral distortions and pulsar timing arrays will also provide competitive sensitivity for keV $\lesssim T_{\mathrm{PT}}\lesssim$ GeV.

    hep-phastro-ph.COPRL(2024)·46 citations
33. 33*

    Status of Direct Determination of Solar Neutrino Fluxes after Borexino

    M. C. Gonzalez-Garcia🇺🇸 · Michele Maltoni🇪🇸 · João Paulo Pinheiro🇪🇸 · Aldo M. Serenelli🇪🇸

    We determine the solar neutrino fluxes from the global analysis of the most up-to-date terrestrial and solar neutrino data including the final results of the three phases of Borexino. The analysis are performed in the framework of three-neutrino mixing with and without accounting for the solar luminosity constraint. We discuss the independence of the results on the input from the Gallium experiments. The determined fluxes are then compared with the predictions provided by the latest Standard Solar Models. We quantify the dependence of the model comparison with the assumptions about the normalization of the solar neutrino fluxes produced in the CNO-cycle as well as on the particular set of fluxes employed for the model testing.

    hep-phastro-ph.SRhep-exJHEP(2024)·25 citations
34. 34*

    Traversing a kinetic pole during inflation: primordial black holes and gravitational waves

    Anish Ghoshal🇵🇱 · Alessandro Strumia🇮🇹

    We consider an inflationary kinetic function with an integrable pole that is traversed during inflation. This scenario leads to enhanced spectra of primordial scalar inhomogeneities with detectable signals: formation of primordial black holes (that could explain Dark Matter) and scalar-induced gravitational waves (that could reproduce the recent Pulsar Timing Array observation, or predict signals in future detectors such as LISA or ET). Spectral signatures depend on whether the inflaton mass dimension at the pole is above or below 2. Values mildly below 2 allow a big power spectrum enhancement with a mild tuning. Finally, we discuss the possibility that a kinetic pole can arise as anomalous dimension of the inflaton due to quantum effects of Planckian particles that become light at some specific inflaton field value.

    hep-phastro-ph.COhep-thJCAP(2024)·14 citations
35. 35*

    Accessing CKM suppressed top decays at the LHC

    Manuel Szewc🇺🇸

    We present an strategy for measuring the off-diagonal elements of the third row of CKM matrix $|V_{tq}|$ through the branching fractions of top quark decays $t\to qW$, where $q$ is a light quark jet. This strategy is an extension of existing measurements, with the improvement rooted in the use of orthogonal $b$- and $q$-taggers that add a new observable, the number of light-quark-tagged jets, to the already commonly used observable, the fraction of $b$-tagged jets in an event. Careful inclusion of the additional complementary observable significantly increases the expected statistical power of the analysis, with the possibility of excluding a null $|V_{td}{|}^2+|V_{ts}{|}^2$ at $95\%$ C.L. at the HL-LHC.

    hep-phhep-ex0 citations
36. 36*

    Off-shell modifications of bound nucleons and parton distributions

    S. I. Alekhin🇩🇪 · S. A. Kulagin🇷🇺 · R. Petti🇺🇸

    We discuss results from our global QCD analyses including nuclear data off deuterium from various measurements, as well as off ${}^3$H and ${}^3$He targets from the MARATHON experiment. We simultaneously determine the parton distribution functions of the proton, the higher-twist terms, and the nucleon off-shell correction functions responsible for the modifications of the partonic structure in bound protons and neutrons. In particular, we study the neutron-proton asymmetry of the off-shell correction and its interplay with the treatment of the higher-twist terms. We observe that the data on the ${}^3$He/${}^3$H cross section ratio are consistent with a single isoscalar off-shell function. We also provide our predictions on the ratio $F_2^n/F_2^p$ and on the $d$ and $u$ quark distributions in the proton and in the ${}^3$H and ${}^3$He nuclei.

    hep-ph0 citations
37. 37*

    Theories of Relativistic Dissipative Fluid Dynamics

    Gabriel S. Rocha🇺🇸 · David Wagner🇩🇪 · Gabriel S. Denicol🇧🇷 · Jorge Noronha🇺🇸 · Dirk H. Rischke🇩🇪

    Relativistic dissipative fluid dynamics finds widespread applications in high-energy nuclear physics and astrophysics. However, formulating a causal and stable theory of relativistic dissipative fluid dynamics is far from trivial; efforts to accomplish this reach back more than 50 years. In this review, we give an overview of the field and attempt a comparative assessment of (at least most of) the theories for relativistic dissipative fluid dynamics proposed until today and used in applications.

    ↳ nucl-thhep-phhep-thphysics.flu-dynEntropy(2024)·77 citations
38. 38*

    Untangling PBH overproduction in $w$-SIGWs generated by Pulsar Timing Arrays for MST-EFT of single field inflation

    Sayantan Choudhury🇮🇳 · Kritartha Dey🇮🇳 · Ahaskar Karde🇮🇳

    Our work highlights the crucial role played by the equation of state (EoS) parameter $w$ within the context of single field inflation with Multiple Sharp Transitions (MSTs) to untangle the current state of the PBH overproduction issue. We examine the situation for a broad interval of EoS parameter that remains most favourable to explain the recent data released by the pulsar timing array (PTA) collaboration. Our analysis yields the interval, $0.2\le w\le 1/3$, to be the most acceptable window from the SIGW interpretation of the PTA signal and where sizeable PBHs abundance, $f_{\mathrm{PBH}}\in (10^{-3},1)$, is observed. We also obtain $w=1/3$, radiation-dominated era, to be the best scenario to explain the early stages of the Universe and address the overproduction problem. Within the range of $1\le c_s\le 1.17$, we construct a regularized-renormalized-resummed scalar power spectrum whose amplitude obeys the perturbativity criterion while being substantial enough to generate EoS dependent scalar induced gravitational waves ($w$-SIGWs) consistent with NANOGrav-15 data. Working for both $c_s=1\mathrm{and}1.17$, we find the $c_s=1.17$ case more favourable for generating large mass PBHs, $M_{\mathrm{PBH}}\sim \mathcal{O}(10^{-6}-10^{-3})M_{\odot }$, as potential dark matter candidates with substantial abundance after constraints coming from microlensing experiments.

    ↳ astro-ph.COgr-qchep-phhep-thFortsch.Phys.(2026)·54 citations
39. 39*

    Corrections to Landau Fermi-liquid fixed-point approximation in nonlinear bosonized theory: Application to $g_A^L$ in nuclei

    Long-Qi Shao🇨🇳 · Mannque Rho🇫🇷

    We calculated in nonlinear bosonized theory $1/\bar{N}$ corrections to the Landau Fermi-liquid fixed-point (FLFP) axial-vector coupling constant in nuclear matter $g_A^L\approx 1$ to which the Landau parameter $F_1^{\omega }$ predominantly contributes. We obtain the correction to $F_1^{\omega }$ to calculate the correction $\delta g_A^L$ to the axial-vector coupling constant $g_A^L$ at the nuclear saturation density. It comes out to be extremely small, $\delta g_A^L\sim O(10^{-4})$. We discuss how the "dilaton-limit fixed-point (DLFP)" result $g_A=1$ can be preserved from finite nuclei to high densities relevant to massive neutron stars and its possible impact on $0\nu \beta \beta$ decay processes involved in going beyond the Standard Model.

    ↳ nucl-thhep-phPRC(2024)·6 citations
40. 40*

    Speed of sound exceeding the conformal bound in dense 2-color QCD

    Etsuko Itou🇯🇵 · Kei Iida🇯🇵

    We review recent works on the Monte Carlo simulations of dense two-color QCD (QC${}_2$D) by focusing on the phase diagram, the equation of state, and the sound velocity at nonzero quark chemical potential. A possible upper bound of the sound velocity is known as the conformal bound, namely, $c_s^2/c^2\le 1/3$. The sound velocity is below the bound at least in the case of finite-temperature QCD. However, our recent work~\cite{Iida:2022hyy} shows the breaking of this bound in dense QC${}_2$D. This phenomenon was previously unknown from any lattice calculations. We also discuss recent related works including lattice studies on QCD at nonzero isospin chemical potential, some effective model analyses, and an analysis based on recent neutron star observations. These works also suggest the breaking of the conformal bound.

    ↳ hep-lathep-phhep-thnucl-thPoS(2024)·5 citations
41. 41*

    Universal relations for compact stars with exotic degrees of freedom

    Anil Kumar · Manoj Kumar Ghosh · Pratik Thakur · Vivek Baruah Thapa · Monika Sinha

    The nature of the highly dense matter inside the supernova remnant compact star is not constrained by terrestrial experiments and hence modeled phenomenologically to accommodate the astrophysical observations from compact stars. The observable properties of the compact stars are highly sensitive to the microscopic model of highly dense matter. However, some universal relations exist between some macroscopic properties of compact stars independent of the matter model. We study the universal relation including the stars containing exotic degrees of freedom such as heavier strange and non-strange baryons, strange quark matter in normal and superconducting phases, etc. We examine the universal relations for quantities moment of inertia - tidal love number - quadrupole moment. We also study the correlation of non-radial f-mode and p-mode frequencies with stellar properties. We find the f-mode frequency observes the universal relation with dimensionless tidal deformability but the p-mode frequency does not show a good correlation with stellar properties. The p-mode frequency is sensitive to the composition of the matter. We find that universal relation is also applicable for stars with exotic matter in the core of the star with several models of exotic matter.

    ↳ astro-ph.HEhep-phnucl-thEPJC(2024)·16 citations
42. 42*

    New evidence of multiple channels for the origin of gamma-ray bursts with extended emission

    Q. M.Li🇨🇳 · Q. B. Sun🇨🇳 · Z. B. Zhang🇨🇳 · K. J. Zhang · G. Long🇨🇳

    Gamma-ray bursts (GRBs) are the most intense explosions in the universe. GRBs with extended emission (GRB EE) constitute a small subclass of GRBs. GRB EE are divided into EE-I GRBs and EE-II GRBs, according to the Amati empirical relationship rather than duration. We test here if these two types of GRB have different origins based on their luminosity function (and formation rate). Therefore, we use Lynden-Bell's c^- method to investigate the LF and FR of GRBs with EE without any assumption. We calculate the formation rate of two types of GRBs. For EE-I GRBs, the fitting function can be written as \rho (z) \propto {(1 + z)^{ - 0.34 \pm 0.04} for z < 2.39 and \rho (z) \propto {(1 + z)^{ - 2.34 \pm 0.24}} for z>2.39. The formation rate of EE-II can describe as \rho (z) \propto {(1 + z)^{ - 1.05 \pm 1.10}} for z<0.43 and \rho (z) \propto {(1 + z)^{ - 8.44 \pm 1.10}} for z>0.43. The local formation rate are \rho (0) = 0.03 Gpc^{-3}yr^{-1} for some EE-I GRBs and \rho (0) = 0.32 Gpc^{-3}yr^{-1} for EE-II GRBs. Based on these results, we provide a new evidence that the origins of EE-I GRBs are different from EE-II GRBs from the perspective of event rate. The EE-I GRB could be produced from the death of the massive star, but EE-II GRB bursts may come from other processes that are unrelated to the SFR. Our findings indicate that the GRB with EE could have multiple production channels.

    ↳ astro-ph.HEhep-phMNRAS(2023)·9 citations
43. 43*

    Massless fermions and superconductivity of string-wall composites

    Minoru Eto🇯🇵 · Yuito Suzuki🇯🇵

    An axion cosmic string is known to be a chiral superconductor when the axion couples to an electrically charged fermion. After the QCD phase transition, a QCD axion string is attached by $N$ domain walls. We would like to elucidate the fate of massless fermions on a global string after domain walls attached not only in the axion model but also in general models having string-wall composites. We investigate the Dirac equation under various string-wall composite backgrounds both in the axion(-like) models and in the $\mathcal{N}=2$ supersymmetry inspired Abelian-Higgs models. We give an answer to the elementary question of whether massless fermions exist, and if so, where they are localized. The answer depends on fermion/boson masses in the models, and the massless fermion can be localized either on the string, on one of the domain walls, or in one of the vacua. We find analytic solutions for the fermion zero mode function by which we prove the existence of the massless fermion on the string-wall composites. We also show supercurrents flowing along the string-wall composites and anomalous electric currents flowing in from outside.

    ↳ hep-thhep-phJHEP(2024)·1 citation
44. 44*

    Mixed scalarization of charged black holes: from spontaneous to non-linear scalarization

    Zakaria Belkhadria🇨🇭 · Alexandre M. Pombo🇨🇿

    Scalarized black holes (BH) have been shown to form dynamically in extended-scalar-tensor theories, either through spontaneous scalarization -- when the BH is unstable against linear perturbations -- or through a non-linear scalarization. In the latter, linearly stable BHs can ignite scalarization when sufficiently perturbed. These phenomena are, however, not incompatible and mixed scalarization is also possible. We explore two aspects of the Einstein-Maxwell-Scalar model: solutions containing, simultaneously, linear (\textit{aka} standard) and non-linear scalarization; and the effects of having one of the coupling constants with an 'opposite sign' to the one leading to scalarization. Both points are addressed by constructing and examining the mixed scalarization's domain of existence. An overall dominance of the spontaneous scalarization over the non-linear scalarization is observed. Thermodynamically, an entropical preference for mixed over the standard scalarization (spontaneous or non-linear) exists. In the presence of counter scalarization, a quench of the scalarization occurs, mimicking the effect of a scalar particle's mass/positive self-interaction term.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2024)·16 citations
45. 45*

    Light fermions in color: why the quark mass is not the Planck mass

    Gustavo P. de Brito🇩🇰 · Astrid Eichhorn🇩🇰 · Shouryya Ray🇩🇰

    We investigate whether quantum gravity fluctuations can break chiral symmetry for fermions that are charged under a $U(1)$ and an $SU(N_{\text{c}})$ gauge symmetry and thus closely resemble Standard-Model fermions. Unbroken chiral symmetry in the quantum-gravity regime is a necessary prerequisite to recover the Standard Model from a joint gravity-matter theory; if chiral symmetry is broken by quantum gravity, fermions cannot generically be much lighter than the Planck mass and the theory is ruled out. To answer this, we work in a Fierz-complete basis of four-fermion interactions and explore whether they are driven to criticality. We discover that the interplay of quantum gravity with the non-Abelian gauge theory results in chiral symmetry breaking, because gravitational and gauge field fluctuations act together to produce bound states. Chiral symmetry breaking is triggered by four-fermion channels that first appear when non-Abelian charges are introduced and that become critical if the non-Abelian symmetry is gauged. Extrapolating our result to the Standard Model fermions, we conjecture that the non-Abelian gauge coupling, Abelian gauge coupling and Newton coupling are all bounded from above, if Standard Model fermions are to remain much lighter than the Planck mass. In contrast, fermions that are charged under a global non-Abelian group can remain light for arbitrarily large values of the Newton coupling. We find that different chiral symmetries are emergent at low energies, depending on the strength of the gravitational coupling. This is an example of fixed points with different degrees of enhanced global symmetry trading stability in fixed-point collisions driven by gravitational fluctuations.

    ↳ hep-thgr-qchep-phPRD(2025)·13 citations
46. 46*

    Cutkosky representation and direct integration

    C. Vergu🇩🇰

    We present a new method of direct integration of Feynman integrals based on the Cutkosky representation of the integrals. In this representation we are able to explicitly compute the integrals which yield square root singularities and leave only the integrals which yield logarithmic singularities, thus making the transcendentality weight manifest. The method is elementary, algorithmic, does not introduce spurious non-physical singularities and does not require a reduction to a basis of pure integrals.

    ↳ hep-thhep-phJHEP(2024)·4 citations
47. 47*

    Dark Matter Scattering Constraints from Observations of Stars Surrounding Sgr A*

    Isabelle John🇸🇪 · Rebecca K. Leane🇺🇸 · Tim Linden🇸🇪

    High resolution infrared data has revealed several young stars in close proximity to Sgr A*. These stars may encounter extremely high dark matter densities. We examine scenarios where dark matter scatters on stellar gas, accumulates in stellar cores, and then annihilates. We study the stars S2, S62, S4711 and S4714 and find three observable effects. First, dark matter interactions can inhibit in situ star-formation close to Sgr A*, favoring scenarios where these stars migrate into the Galactic Center. Second, dark matter interactions can delay main sequence evolution, making stars older than they appear. Third, very high dark matter densities can inject enough energy to disrupt main sequence stars, allowing S-star observations to constrain the dark matter density near Sgr A*.

    ↳ astro-ph.HEastro-ph.SRhep-phPRD(2024)·31 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.