Tue·Feb 21, 2023Tuesday·February 21, 2023

1. 01*

   Gravitational waves from $\mathrm{SU}($$N$$)/Sp($$N$$)$ composite Higgs models

   Mads T. Frandsen🇩🇰 · Matti Heikinheimo🇫🇮 · Martin Rosenlyst🇬🇧 · Mattias E. Thing🇩🇰 · Kimmo Tuominen🇫🇮

   We study possible strong first-order electroweak phase transitions in Composite Higgs models and we quantify the part of parameter space that can be probed with future gravitational Wave experiments. We focus on models where the Composite Higgs sector arises from underlying four-dimensional strongly interacting gauge theories with fermions, and where the Standard Model fermion masses are induced via linear mixing terms with composite fermions -- the so-called fermion partial compositeness framework. We perform our analysis for the general class of Composite Higgs models arising from $N$ Weyl fermions in a pseudo-real representation of the new strongly interacting gauge group that dynamically triggers the global chiral symmetry breaking pattern $\mathrm{SU}($$N$$)\to \mathrm{Sp}($$N$$)$. The minimal model has $N=4$ and for $N>4$ the models feature complex scalar dark matter candidates arising as pseudo-Nambu-Goldstone bosons. We find a large number of points in the models parameter space which yield strong first-order electroweak phase transitions and identify the most important operators characterizing the strength of the phase transition. Almost all of these points are testable with future GW detectors such as LISA, Taiji, Tianqin, BBO, DECIGO and Ultimate-DECIGO.

   hep-phJHEP(2023)·15 citations
2. 02*

   Light front synchronization and rest frame densities of the proton: Electromagnetic densities

   Adam Freese🇺🇸 · Gerald A. Miller🇺🇸

   We clarify the physical origin and meaning of the two-dimensional relativistic densities of the light front formalism. The densities are shown to originate entirely from the use of light front time instead of instant form time, which physically corresponds to using an alternative synchronization convention. This is shown by using tilted light front coordinates, which consist of light front time and ordinary spatial coordinates, and which are also used to show that the obtained densities describe a system at rest rather than at infinite momentum. These coordinates allow all four components of the electromagnetic current density to be given clear physical meanings. We explicate the formalism for spin-half targets, obtaining charge and current densities of the proton and neutron using empirical form factor parametrizations, as well as up and down quark densities and currents. Angular modulations in the densities of transversely-polarized states are explained as originating from redshifts and blueshifts due to quarks moving in different longitudinal directions.

   hep-phnucl-thPRD(2023)·13 citations
3. 03*

   Dark Matter and $(g-2{)}_{e,\mu }$ in ISS(2,3) based Gauged $U(1{)}_{L_e-L\mu }$ Symmetric Model

   Rishu Verma🇮🇳 · Ankush🇮🇳 · B. C. Chauhan🇮🇳

   We proposed a model which can explain the neutrino phenomenology, dark matter and anomalous magnetic moment$(g-2)$ in a common framework. The inverted sea saw (ISS)(2,3) mechanism has been incorporated, in which we get an extra sterile state and this state act as a viable dark matter candidate. The right handed neutrino mass is obtained in TeV scale, which is accessible at LHC. The anomaly free $U(1{)}_{L_e-L\mu }$ gauge symmetry is introduced to explain the anomalous magnetic moment of electron and muon because it provides a natural origin of $(g-2)$ in a very minimal setup. The corresponding MeV scale gauge boson successfully explain the anomalous magnetic moment of electron and muon$(g-2{)}_{e,\mu }$, simultaneously. Thus obtained neutrino phenomenology and relic abundance of dark matter are compatible with experimental results.

   hep-phPhys.Dark Univ.(2023)·3 citations
4. 04*

   Sterile neutrino dark matter: relativistic freeze-out

   Oleg Lebedev🇫🇮 · Takashi Toma🇯🇵

   Long-lived sterile neutrinos can play the role of dark matter. We consider the possibility that such neutrinos form a thermal bath with a singlet scalar, while not being in thermal equilibrium with the Standard Model fields. Eventually, the neutrino dark matter undergoes freeze-out in the dark sector, which can occur in both non-relativistic and relativistic regimes. To account for the latter possibility, we use the full Fermi-Dirac and Bose-Einstein distribution functions with effective chemical potential in the reaction rate computation. This allows us to study the freeze-out process in detail and also obtain the necessary thermalization conditions. We find that relativistic freeze-out occurs in a relatively small part of the parameter space. In contrast to the standard weakly-interacting-massive-particle (WIMP) scenario, the allowed dark matter masses extend to $10^4$ TeV without conflicting perturbativity.

   hep-phastro-ph.COJHEP(2023)·11 citations
5. 05*

   Discernible NSI Effects in Long-Baseline Neutrino Experiments

   Barnali Brahma🇮🇳 · Anjan Giri🇮🇳

   Neutrino oscillation in the matter could get affected by the sub-dominant, yet unknown, non-standard interactions. The upcoming long-baseline (LBL) neutrino experiments will be sensitive to these effects and can provide information on the unknown oscillation parameter values. In this article, we study the parameter degeneracies that can occur in DUNE, T2HK experiments, and a combination of both due to nonstandard interactions (NSI), arising simultaneously, from two different off-diagonal sectors, i.e., $e-\mu$ and $e-\tau$. We derive constraints on both the NSI sectors using the combined datasets of NO$\nu$A and T2K. Our analysis reveals a significant impact that dual NSIs may have on the sensitivity of atmospheric mixing angle ${\theta }_{23}$ in the normal ordering (NO) case. Furthermore, when non-standard interaction from the $e-\mu$ and $e-\tau$ sectors are included, we see significant changes in the probabilities for DUNE, T2HK, and as well as a combined analysis involving both. Moreover, the CP sensitivity gets affected significantly due to the presence of dual NSIs, and, in addition, the CP asymmetry also exhibits an appreciable difference.

   hep-ph9 citations
6. 06*

   Lepton $g-2$ and $W$-boson mass anomalies in the DFSZ axion model

   Moslem Ahmadvand🇮🇷 · Fazlollah Hajkarim🇮🇹

   With regard to the leptonic magnetic dipole moment anomaly as well as the $W$-boson mass excess, we study the DFSZ axion model. Considering theoretical and experimental constraints, we show that the muon and electron $g-2$ anomalies can be explained within the parameter space of the model for extra Higgs bosons with mass spectra around the electroweak scale and for an almost equivalent contribution of one- and two-loop diagrams. A negative electron $g-2$ could be achieved by introducing heavy neutrinos. Furthermore, the $W$ boson mass excess can be consistently addressed within the mass range of the matter content testable at collider experiments.

   hep-phEPJC(2023)·5 citations
7. 07*

   Event-activity dependent production of strange and non-strange charmed baryons in the enhanced color-reconnection scheme

   Zoltán Varga🇭🇺 · Anett Misák🇭🇺 · Róbert Vértesi🇭🇺

   We investigated the production of charmed baryons with different isospin and strangeness content, compared to both charmed $D^0$ mesons and to the ${\Lambda }_c^{+}$ baryon in proton--proton collisions at LHC energies. We used the PYTHIA 8 Monte Carlo event generator with color-reconnection beyond leading color approximation and proposed methods based on event-activity classifiers to probe the source of the charm baryon enhancement. We conclude that in the considered model class, the isospin of the charmed baryon state has a strong impact on the enhancement pattern. Using the observables we propose, upcoming high-precision experimental data will be able to differentiate between mechanisms of strangeness and charm enhancement.

   hep-phJ.Phys.G(2023)·3 citations
8. 08*

   Fermi-LAT GeV excess and muon $g-2$ in a modular $A_4$ symmetry

   Jongkuk Kim🇰🇷 · Hiroshi Okada🇰🇷

   The recent measurement of muon anomalous magnetic dipole moment (muon $g-2$) suggests that there might exist new physics that dominantly interacts with muons. The observed gamma-ray excess from Fermi-LAT indicates that dark matter annihilates into a specific charged fermions. We propose a successful model simultaneously to explain the Fermi-LAT GeV gamma-ray excess and sizable muon $g-2$ with a modular $A_4$ symmetry. Due to nature of this symmetry, our DM only interacts with pairs of muon and we explain sizable muon $g-2$ without suffering from constraints of any lepton flavor violations. We numerically show our allowed spaces on each measurements of Fermi-LAT, relic density of DM and muon $g-2$, randomly scanning our input parameters.

   hep-ph15 citations
9. 09*

   Boosting indirect detection of a secluded dark matter sector

   Jinmian Li🇨🇳 · Takaaki Nomura🇨🇳 · Junle Pei🇨🇳 · Xiangwei Yin🇨🇳 · Cong Zhang🇨🇳

   Dark Matter (DM) residing in a secluded sector with suppressed portal interaction could evade direct detections and collider searches. The indirect detections provide the most robust probe to this scenario. Depending on the structure of the dark sector, novel DM annihilation spectra are possible. The dark shower is a common phenomenon for particles in the dark sector which take part in strong interactions and are boosted. In terms of simplified two-component DM models with vector portal interaction and pseudoscalar portal interaction, we study the dark showering effects for DM indirect detection. In those models, the heavier DM component which dominates the relic density annihilates into boosted lighter species. Together with the large coupling through which the lighter DM annihilates away in the early universe, the showered spectra provide as the smoking gun for the DM existence. Considering bounds obtained by the AMS-02 positron data and Fermi-LAT measurement of gamma-ray from the dwarf galaxies, we find the dark shower could open a new region of sensitivity that can not be probed before.

   hep-phhep-exPRD(2023)·6 citations
10. 10*

    KeV dark matter in minimal extended seesaw model and its predictions in neutrinoless double beta decay and baryogenesis

    Mayengbam Kishan Singh🇮🇳 · S. Robertson Singh🇮🇳 · N. Nimai Singh🇮🇳

    We develop an $A_4\times Z_4\times Z_2$ symmetry extension of Standard Model under the minimal extended seesaw (MES) mechanism which successfully predicts neutrino masses and mixings patterns. This model breaks $\mu -\tau$ symmetry of neutrino mass matrix and explains leptonic mixing with non-zero ${\theta }_{13}$. We study the phenomenological results of the keV-scale sterile neutrino as a dark matter candidate along with other phenomenologies such as neutrino oscillation observables, neutrinoless double beta decay, baryogenesis via leptogenesis, etc. Dirac CP-violating phase ${\delta }_{CP}$ and two Majorana phases $\alpha$ and $\beta$ are also calculated from the leptonic mixing matrix. Best-fit values of the model parameters and neutrino observables are calculated from ${\chi }^2$ analysis. The model predicts best-fit values of neutrino mixing angles to be ${\sin }^2{\theta }_{23}=0.555,{\sin }^2{\theta }_{12}=0.301$ and ${\sin }^2{\theta }_{13}=0.022$ for normal hierarchy. Significant results consistent with experimental data are also observed for effective neutrino mass $m_{\beta \beta }\sim (0.97-5.02)$ meV, effective electron mass $m_{\beta }\sim (0.084-0.41)$eV and sum of active neutrino masses $\sum m_i<0.12$ eV. The model does not favour Inverted hierarchy at the 3$\sigma$ level with the given parameter space.

    hep-ph0 citations
11. 11*

    One-loop Lipatov vertex in QCD with higher $ϵ$-accuracy

    Victor S. Fadin🇷🇺 · Michael Fucilla🇮🇹 · Alessandro Papa🇮🇹

    The effective Reggeon-Reggeon-gluon vertex, known as Lipatov vertex, is the key ingredient that allows to develop the BFKL approach in QCD. Within the next-to-leading logarithmic approximation, it is sufficient to know its one-loop corrections, in dimensional regularization ($D=4+2ϵ$), up to the constant term in the $ϵ$-expansion. In the next-to-next-to-leading approximation, however, the one-loop Lipatov vertex is needed up to the order ${ϵ}^2$. In this paper we present the expression for this vertex in dimensional regularization up to the required accuracy.

    hep-phhep-thJHEP(2023)·28 citations
12. 12*

    Low Energy Neutrino and Mass Dark Matter Detection Using Freely Falling Atoms

    Alim Ruzi🇨🇳 · Sitian Qian🇨🇳 · Tianyi Yang🇨🇳 · Qiang Li🇨🇳

    We propose a new method to detect low-energy neutrinos and low-mass dark matter at or below the MeV scale, through their coherent scatterings from freely falling heavy atoms and the resulting kinematic shifts. We start with a simple calculation for illustration: for $10^7$ heavy atoms of a mass number around 100 with a small recoil energy of 1 meV, the corresponding velocities can reach $0.01,m/s$ and produce significant kinematic shifts that can be detected. We then show that the proposed device should be able to probe vast low-energy regions of neutrinos from meV to MeV and can surpass previous limits on sub-MeV dark matter by several orders of magnitude. Such a proposal can be useful to (1) detect sub-MeV-scale dark matter: with $10^2$ atom guns shooting downwards, for example, CsI or lead clusters consisting of $10^7$ atoms with a frequency around $10^3$ Hz, it can already be sensitive to scattering cross-sections at the level of $10^{-33(-34)}{\mathrm{cm}}^2$ for 1 (0.1) MeV dark matter and surpass current limits. Technological challenges include high-quality atom cluster production and injections. (2) Measure coherent neutrino-nuclei scatterings at the 0.1-1 MeV region for the first time: with $10^4$ atom guns shooting downwards CsI clusters consisting of $10^{11}$ atoms and a frequency of $10^6$ Hz. One can expect 10 events from MeV solar neutrinos to be observed per year. Furthermore, (3) this method can be extended to probe very low-energy neutrinos down to the eV-KeV region and may be able to detect the cosmic neutrino background, although it remains challenging.

    hep-phastro-ph.HEcond-mat.mes-hallhep-ex+14 citations
13. 13*

    Isospin symmetry of $\omega$ meson in the soft-wall model of holographic QCD at finite temperature

    Narmin Nasibova🇦🇿

    Coupling constants of $\rho$- and $\omega$- meson-nucleon are related with each other by isospin relation. In present work, it is aimed at studying the violation (if it exists) of isospin symmetry of the $\omega$-meson and to study the temperature dependence of $\omega$-meson-nucleon-delta and $\omega$-meson-delta coupling constants using the soft-wall model of holographic QCD. Firstly, the coupling constants are obtained by applying the profile functions of the vector and fermion fields to the model at a finite temperature. The interaction Lagrangian is written, including the minimum and magnetic interactions of vector and fermion fields which is defined in the bulk of the 5-dimensional AdS space-time. Secondly, the temperature dependence of the coupling constants $g_{\omega NN}(T)$, $g_{\omega \Delta \Delta }(T)$ and $g_{\omega N\Delta }(T)$ has been plotted. Comparing $g_{\omega NN}(T)$ with the coupling constant $g_{\rho NN}(T)$, it obtained that the isospin symmetry of the omega meson is not violated at the finite temperature. It is also observed that the coupling constants of the $\omega$ vector meson with baryons decreases with increasing temperature, and this coupling constant becomes zero near the Hawking phase transition temperature.

    hep-phFew Body Syst.(2025)·2 citations
14. 14*

    The result of the Neutrino-4 experiment, sterile neutrinos and dark matter, the fourth neutrino and the Hubble constant

    A.P. Serebrov🇷🇺 · R.M. Samoilov🇷🇺 · M.E. Chaikovskii🇷🇺 · O.M. Zherebtsov🇷🇺

    A brief analysis of the result of the Neutrino-4 experiment and the results of other experiments on the search for a sterile neutrino is presented. It is noted that a joint analysis of the results of the Neutrino-4 experiment and the data of the GALLEX, SAGE and BEST experiments confirms the parameters of neutrino oscillations declared by the Neutrino-4 experiment ($\Delta m_{14}^2=7.3{\text{eV}}^2$ and ${\sin }^{2}2{\theta }_{14}\approx 0.36$) and increases the confidence level to $5.8\sigma$. An estimate of the contribution of sterile neutrinos with these parameters to the energy density of the Universe is made. It amounted to 5.3%. It is discussed that the extension of the neutrino model by introducing two more heavy sterile neutrinos in accordance with the number of types of active neutrinos will make it possible to explain the large-scale structure of the Universe and bring the contribution of sterile neutrinos to the dark matter of the Universe to the level of 27%. Possible contradictions between the measured sterile neutrino parameters and cosmological constraints are analyzed. It is shown that, based on modern astrophysical data, it is impossible to draw a definite conclusion in favor of the model of three or four neutrinos. It is noted that the introduction of the fourth neutrino removes the Hubble tension problem without contradictions with cosmic microwave background observed by the Planck collaboration. The influence of lepton asymmetry on the comparison of models of three or four neutrinos is considered. An estimate was made for the upper limit of the lepton asymmetry $L_e<0.02$. The possibility of the appearance of lepton asymmetry due to CP violation during oscillations into sterile neutrinos is discussed.

    hep-ph7 citations
15. 15*

    A vacuum transition in the FSM with a possible new take on the horizon problem in cosmology

    Jose Bordes (1)🇪🇸 · HM Chan (2)🇬🇧 · ST Tsou (3) ((1) Departament Fisica Teorica and IFIC, CSIC-Universitat de Valencia (Spain), (2) Rutherford Appleton Laboratory (UK) (3) Mathematical Institute, University of Oxford (UK))🇬🇧

    The framed standard model (FSM), constructed to explain the empirical mass and mixing patterns of quarks and leptons, gives the same result as the standard model in almost all areas in particle physics where it has been successfully applied, except for a few deviations such as the W mass and the g-2 of muons, where experiment is showing departures from what SM predicts. It predicts further the existence of a hidden sector of particles which may function as dark matter. In this paper, we first note that the above results involve the FSM undergoing a vacuum transition at a scale of around 17 MeV, where the vev's of the colour framons which are all nonzero above that scale acquire some vanishing components below it. This implies that the metric pertaining to these vanishing components would vanish also. Consequences should then ensue, mostly in the unknown hidden sector where empirical confirmation is hard at present to come by, but they give small reflections in the standard sector, some of which may have already been seen. However, one notes that if one imagines colour to be embedded, Kaluza-Klein fashion, into a higher dimensional space-time, then this VTR1 would cause 2 of the compactified dimensions to collapse. This might mean that when the universe cooled to the corresponding temperature of $10^{11}$K when it was about $10^{-3}$s old, this VTR1 collapse would cause the 3 spatial dimensions of the universe to expand to compensate. The resultant expansion is estimated, using FSM parameters previously determined from particle physics, to be capable, when extrapolated backwards in time, of bringing the present universe back inside the then horizon, solving thus formally the horizon problem. Besides, VTR1 being a global phenomenon in the FSM, it would switch on and off automatically and simultaneously over all space, thus requiring no additional strategy for a graceful exit.

    hep-phastro-ph.COInt.J.Mod.Phys.A(2023)·3 citations
16. 16*

    Pionic transitions from $Z_c(4020)$ to $D$ wave charmonia

    Xiao-Yu Qi🇨🇳 · Qi Wu🇨🇳 · Dian-Yong Chen🇨🇳

    In the present work, we investigate the charmed meson loops contributions to the pionic transitions from $Z_c(4020{)}^{+}$ to the $D$ wave triplets charmonia by using an effective Lagrangian approach. Our estimations indicate that the predicted branching fraction of $Z_c(4020{)}^{+}\to {\pi }^{+}\psi (1^3{D}_J),J=(1,2,3)$ are much smaller than the one of $Z_c(4020{)}^{+}\to {\pi }^{+}{h}_c$. Thus, searching $Z_c(4020{)}^{\pm }$ in the ${\pi }^{\pm }\psi (1^3{D}_J)$ invariant mass distributions is impossible. Thus, the observed peak structures at 4.04 and 4.13 GeV in the ${\pi }^{\pm }\psi (3770)$ invariant mass distributions should not come from the contributions of $Z_c(4020{)}^{\pm }$, and further precise experimental measurements of the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}\psi (3770)$ process are needed to decode the nature of these two peak structures.

    hep-phhep-exEPJC(2023)·3 citations
17. 17*

    Electromagnetic instability of compact axion stars

    Liina M. Chung-Jukko🇬🇧 · Eugene A. Lim🇬🇧 · David J. E. Marsh🇬🇧 · Josu C. Aurrekoetxea🇬🇧 · Eloy de Jong🇬🇧 · Bo-Xuan Ge🇬🇧

    If the dark matter is composed of axions, then axion stars are expected to be abundant in the Universe. We demonstrate in fully non-linear (3+1) numerical relativity the instability of compact axion stars due to the electromagnetic Chern-Simons term. We show that above the critical coupling constant $g_{a\gamma }^{\mathrm{crit}}\propto M_s^{-1.35}$, compact axion stars of mass $M_s$ are unstable. The instability is caused by parametric resonance between the axion and the electromagnetic field. The existence of stable compact axion stars requires approximately Planck-suppressed couplings to photons. If the coupling exceeds the critical value, then all stable axion stars are necessarily non-compact. Unstable axion stars decay leaving behind a less massive, less compact, remnant. The emitted radiation peaks at frequency $\omega \sim 1/R_s$, where $R_s$ is the axion star radius.

    hep-phastro-ph.COgr-qchep-thPRD(2023)·23 citations
18. 18*

    Implementation of Cluster expansion for hot QCD matter

    Niels-Uwe Friedrich Bastian🇵🇱 · Pasi Huovinen🇵🇱 · Elizaveta Nazarova🇷🇺

    We present a cluster expansion EoS model for strongly-interacting matter based on the generalized Beth-Uhlenbeck formalism to describe hadrons as bound clusters of quarks. This formalism can describe both confined and deconfined phases. Our emphasis is on the region of vanishing baryon densities, where numerical solutions available from Lattice QCD predict a smooth crossover transition from hadron to quark matter. Medium effects are taken into account as self energies, which are motivated from both perturbative QCD calculations and phenomenological models. Parameters are tuned to Lattice QCD data and result in a good agreement of the thermodynamics.

    hep-phnucl-thNPA(2023)·2 citations
19. 19*

    Neutrino oscillation caused by spacetime geometry

    Indrajit Ghose🇮🇳 · Riya Barick🇮🇳 · Amitabha Lahiri🇮🇳

    Effects of gravitational interaction are generally neglected in particle physics. A first order formulation of gravity is presented to include gravity in Quantum Mechanical Lagrangian of fermions. It is seen that fermions minimally coupled to gravity gives rise to a torsionless effective theory with a quartic interaction. After passing through a thermal background the most generic form of contortion contributes to neutrino effective mass. This effective mass can change the current oscillation parameters.

    hep-phLHEP(2023)·9 citations
20. 20*

    Axion Star Explosions: A New Source for Axion Indirect Detection

    Miguel Escudero🇨🇭 · Charis Kaur Pooni🇬🇧 · Malcolm Fairbairn🇬🇧 · Diego Blas🇪🇸 · Xiaolong Du🇺🇸 · David J. E. Marsh🇬🇧

    If dark matter is composed of axions, then axion stars form in the cores of dark matter halos. These stars are unstable above a critical mass, decaying to radio photons that heat the intergalactic medium, offering a new channel for axion indirect detection. We recently provided the first accurate calculation of the axion decay rate due to axion star mergers. In this work we show how existing data concerning the CMB optical depth leads to strong constraints on the axion photon coupling in the mass range $10^{-14}\mathrm{eV}\lesssim m_a\lesssim 10^{-8}\mathrm{eV}$. Axion star decays lead to efficient reionization of the intergalactic medium during the dark ages. By comparing this non-standard reionization with Planck legacy measurements of the Thompson optical width, we show that couplings in the range $10^{-14}{\mathrm{GeV}}^{-1}\lesssim g_{a\gamma \gamma }\lesssim 10^{-10}{\mathrm{GeV}}^{-1}$ are excluded for our benchmark model of axion star abundance. Future measurements of the 21cm emission of neutral hydrogen at high redshift could improve this limit by an order of magnitude or more, providing complementary indirect constraints on axion dark matter in parameter space also targeted by direct detection haloscopes.

    hep-phastro-ph.COastro-ph.HEPRD(2024)·62 citations
21. 21*

    Model-Independent Radiative Symmetry Breaking and Gravitational Waves

    Alberto Salvio🇮🇹

    Models where symmetries are predominantly broken (and masses are then generated) through radiative corrections typically produce strong first-order phase transitions with a period of supercooling, when the temperature dropped by several orders of magnitude. Here it is shown that a model-independent description of these phenomena and the consequent production of potentially observable gravitational waves is possible in terms of few parameters (which are computable once the model is specified) if enough supercooling occurred. It is explicitly found how large the supercooling should be in terms of those parameters, in order for the model-independent description to be valid. It is also explained how to systematically improve the accuracy of such description by computing higher-order corrections in an expansion in powers of a small quantity, which is a function of the above-mentioned parameters. Furthermore, the corresponding gravitational wave spectrum is compared with the existing experimental results from the latest observing run of LIGO and VIRGO and the expected sensitivities of future gravitational wave experiments to find regions of the parameter space that are either ruled out or can lead to a future detection.

    hep-phastro-ph.COgr-qchep-thJCAP(2023)·25 citations
22. 22*

    The LPM effect in sequential bremsstrahlung: gluon shower development

    Peter Arnold🇺🇸 · Omar Elgedawy🇺🇸 · Shahin Iqbal🇵🇰

    We give details of our study of whether high-energy gluon showers inside a QCD medium can be treated as a sequence of individual splitting processes $g\to gg$, or whether there is significant quantum overlap between where one splitting ends and the next begins (neglecting effects that can be absorbed into an effective value of the jet quenching parameter $\hat{q}$ that characterizes the medium). The study is carried out by imagining in-medium gluon shower development in the simplest theoretical situation, which includes imagining a very large, static, homogeneous medium and taking the large $N_{\mathrm{c}}$ limit. Along the way, we also show how in-medium shower evolution can be written in terms of a "net" splitting rate $[d\Gamma /dx{]}_{\mathrm{net}}$, and we provide a moderately simple analytic fit to our numerical results for the overlap effects included in that rate, which we hope may be of use to others wishing to study possible consequences of overlapping splittings.

    hep-phnucl-thPRD(2023)·28 citations
23. 23*

    Unified tetraquark equations

    A. N. Kvinikhidze🇬🇪 · B. Blankleider🇦🇺

    We derive covariant equations describing the tetraquark in terms of an admixture of two-body states $D\bar{D}$ (diquark-antidiquark), $MM$ (meson-meson), and three-body-like states $q\bar{q}(T_{q\bar{q}})$, $qq(T_{\bar{q}\bar{q}})$, and $\bar{q}\bar{q}(T_{qq})$ where two of the quarks are spectators while the other two are interacting (their t matrices denoted correspondingly as $T_{q\bar{q}}$, $T_{\bar{q}\bar{q}}$, and $T_{qq}$). This has been achieved by describing the $qq\bar{q}\bar{q}$ system using the Faddeev-like four-body equations of Khvedelidze and Kvinikhidze [Theor. Math. Phys. 90, 62 (1992)] while retaining all two-body interactions (in contrast to previous works where terms involving isolated two-quark scattering were neglected). As such, our formulation, is able to unify seemingly unrelated models of the tetraquark, like, for example, the $D\bar{D}$ model of the Moscow group [Faustov et al., Universe 7, 94 (2021)] and the coupled channel $D\bar{D}-MM$ model of the Giessen group [Heupel et al., Phys. Lett. B718, 545 (2012)].

    hep-phnucl-thPRD(2023)·6 citations
24. 24*

    A Search for Low-mass Dark Matter via Bremsstrahlung Radiation and the Migdal Effect in SuperCDMS

    M.F. Albakry · I. Alkhatib · D. Alonso · D.W.P. Amaral · T. Aralis · T. Aramaki · I.J. Arnquist · I. Ataee Langroudy · E. Azadbakht · S. Banik · C. Bathurst · R. Bhattacharyya and 121 other authors

    We present a new analysis of previously published of SuperCDMS data using a profile likelihood framework to search for sub-GeV dark matter (DM) particles through two inelastic scattering channels: bremsstrahlung radiation and the Migdal effect. By considering these possible inelastic scattering channels, experimental sensitivity can be extended to DM masses that are undetectable through the DM-nucleon elastic scattering channel, given the energy threshold of current experiments. We exclude DM masses down to $220\text{MeV}/c^2$ at $2.7\times 10^{-30}{\text{cm}}^2$ via the bremsstrahlung channel. The Migdal channel search provides overall considerably more stringent limits and excludes DM masses down to $30\text{MeV}/c^2$ at $5.0\times 10^{-30}{\text{cm}}^2$.

    ↳ hep-exhep-phPRD(2023)·62 citations
25. 25*

    QCD Thermodynamics and Neutral Pion in a Uniform Magnetic Field: Finite Volume Effects

    Prabal Adhikari🇺🇸 · Brian C. Tiburzi🇺🇸

    We address finite volume effects of lattice QCD calculations in background magnetic fields. Using chiral perturbation theory at next-to-leading order, volume effects are calculated for thermodynamic quantities: the chiral condensate, pressure anisotropy, and magnetization. The neutral pion effective action in a finite volume is additionally derived. For these charge neutral observables, volume and source averaging are shown to capitalize on magnetic periodicity, which is the remnant translational invariance of the finite-volume theory. For a fixed magnetic field strength, certain volume and source averaged quantities are independent of the size of the lattice transverse to the magnetic field. Despite this simplifying feature, finite volume corrections to the magnetic field dependence of the chiral condensate and neutral pion magnetic polarizability can be non-negligible. The pressure anisotropy at fixed magnetic flux, moreover, appears acutely sensitive to the lattice volume.

    ↳ hep-lathep-phnucl-thPRD(2023)·16 citations
26. 26*

    Positronium Physics and Biomedical Applications

    Steven D. Bass🇵🇱 · Sebastiano Mariazzi🇮🇹 · Pawel Moskal🇵🇱 · Ewa Stepien🇵🇱

    Positronium is the simplest bound state, built of an electron and a positron. Studies of positronium in vacuum and its decays in medium tell us about Quantum Electrodynamics, QED, and about the structure of matter and biological processes of living organisms at the nanoscale, respectively. Spectroscopic measurements constrain our understanding of QED bound state theory. Searches for rare decays and measurements of the effect of gravitation on positronium are used to look for new physics phenomena. In biological materials positronium decays are sensitive to the inter- and intra-molecular structure and to the metabolism of living organisms ranging from single cells to human beings. This leads to new ideas of positronium imaging in medicine using the fact that during positron emission tomography (PET) as much as 40% of positron annihilation occurs through the production of positronium atoms inside the patient's body. A new generation of the high sensitivity and multi-photon total-body PET systems opens perspectives for clinical applications of positronium as a biomarker of tissue pathology and the degree of tissue oxidation.

    ↳ physics.med-phhep-phphysics.ins-detRMP(2023)·57 citations
27. 27*

    Bayesian quantification of strongly-interacting matter with color glass condensate initial conditions

    Matthew R. Heffernan🇨🇦 · Charles Gale🇨🇦 · Sangyong Jeon🇨🇦 · Jean-François Paquet🇺🇸

    A global Bayesian analysis of relativistic Pb + Pb collisions at ${\sqrt{s}}_{\mathrm{NN}}$ = 2.76 TeV is performed, using a multistage model consisting of an IP-Glasma initial state, a viscous fluid dynamical evolution, and a hadronic transport final state. The observables considered are from the soft sector hadronic final state. Posterior and Maximum a Posteriori parameter distributions that pertain to the IP-Glasma and hydrodynamic phases are obtained, including the shear and bulk specific viscosity of strong interacting matter. The first use of inference with transfer learning in heavy-ion analyses is presented, together with Bayes Model Averaging.

    ↳ nucl-thhep-phnucl-exPRC(2024)·55 citations
28. 28*

    Phenomenological Relativistic Second-Order Hydrodynamics for Multiflavor Fluids

    Arus Harutyunyan🇦🇲 · Armen Sedrakian🇩🇪

    In this work, we perform a phenomenological derivation of the first- and second-order relativistic hydrodynamics of dissipative fluids. To set the stage, we start with a review of the ideal relativistic hydrodynamics from energy-momentum and particle number conservation equations. We then go on to discuss the matching conditions to local thermodynamical equilibrium, symmetries of the energy-momentum tensor, decomposition of dissipative processes according to their Lorentz structure, and finally, the definition of the fluid velocity in the Landau and Eckart frames. With this preparatory work, we first formulate the first-order (Navier-Stokes) relativistic hydrodynamics from the entropy flow equation, keeping only the first-order gradients of thermodynamical forces. A generalized form of diffusion terms is found with a matrix of diffusion coefficients describing the relative diffusion between various flavors. The procedure of finding the dissipative terms is then extended to the second order to obtain the most general form of dissipative function for multiflavor systems up to the second order in dissipative fluxes. The dissipative function now includes in addition to the usual second-order transport coefficients of Israel-Stewart theory also second-order diffusion between different flavors. The relaxation-type equations of second-order hydrodynamics are found from the requirement of positivity of the dissipation function, which features the finite relaxation times of various dissipative processes that guarantee the causality and stability of the fluid dynamics. These equations contain a complete set of nonlinear terms in the thermodynamic gradients and dissipative fluxes arising from the entropy current, which are not present in the conventional Israel-Stewart theory.

    ↳ nucl-thastro-ph.HEhep-phSymmetry(2023)·6 citations
29. 29*

    Constraint on the minimally extended varying speed of light using time dilations in type Ia supernovae

    Seokcheon Lee🇰🇷

    The Friedmann-Lemaître-Robertson-Walker model establishes the correlation between redshifts and distances. It has a metric expansion of space. As a result, the wavelength of photons propagating through the expanding space is stretched, creating the cosmological redshift, $z$. It also relates the frequency of light detected by a local observer to that emitted from a distant source. In standard cosmology (\textit{i.e.}, a constant speed light model), this relation is given by a factor $1/(1+z)$. However, this ratio is modified in the minimally extended varying speed of light model (meVSL, $c=c_0{a}^{b/4}$) as $1/(1+z{)}^{1-b/4}$. This time dilation effect is detected as the observed rate of the time variation in the intensity of emitted radiation. The spectra of type Ia supernovae (SNe Ia) provide a reliable way to measure the apparent aging rate of distant objects. We use data on 13 high-redshift ($0.28\le z\le 0.62$) SNe Ia to obtain $b=0.198\pm 0.415$ at the $1$-$\sigma$ confidence interval. The current data is too sparse to give meaningful constrain on the meVSL and cannot distinguish the meVSL model from the standard model.

    ↳ astro-ph.COgr-qchep-phMNRAS(2023)·19 citations
30. 30*

    Energy recovery twin linear $e^{+}{e}^{-}$, $e^{-}{e}^{-}$ colliders (ERLC ) with high luminosities and accelerating gradients

    V.I. Telnov (1 and 2) ((1) Budker Institute of Nuclear Physics, Novosibirsk, Russia, (2) Novosibirsk State University, Novosibirsk, Russia)🇷🇺

    A recently proposed superconducting linear collider with energy recovery (ERLC) and multiple beam reuse employs twin RF structures to eliminate parasitic collisions in the linacs. Such a collider can operate in either pulsed or continuous-wave (CW) mode, achieving a luminosity of $\mathcal{O}(10^{36})$ cm${}^{-2}$s${}^{-1}$ at $2E_0$ = 250--500 GeV. This paper demonstrates that in pulsed mode, the ERLC luminosity is independent of the accelerating gradient for a fixed total power, enabling operation at the highest available gradients. A similar independence holds for the CW mode when the available power significantly exceeds the operational threshold. The luminosity scales with the cavity quality factor as $L\propto Q_0^{1/2}$. We also present, for the first time, a study of a twin $e^{-}{e}^{-}$ ERLC and estimate its performance. This configuration is simpler than the $e^{+}{e}^{-}$ version as it eliminates the need for beam recirculation; electrons can be generated anew for each cycle. In this case, the luminosity scales as $L\propto Q_0^{1/4}$. Furthermore, the use of traveling-wave (TW) RF structures allows for higher gradients and reduced thermal loading. We show that an ERLC with $G$ = 40 MeV/m can operate in CW mode, reaching luminosities of $L_{e^{+}{e}^{-}}$= (1-2.5)$\times 10^{36}$ and $L_{e^{-}{e}^{-}}$= (3-7)$\times 10^{36}$ cm${}^{-2}$s${}^{-1}$ at $2E_0$ = 250 and 500 GeV, respectively, with a total power consumption of 150-300 MW. These results position the ERLC as a highly promising candidate for a future Higgs factory.

    ↳ physics.acc-phhep-exhep-phNucl.Instrum.Meth.A(2026)·1 citation
31. 31*

    Exploring the hidden Universe: A novel phenomenological approach for recovering arbitrary gravitational-wave millilensing configurations

    Anna Liu🇨🇳 · Isaac C. F. Wong🇨🇳 · Samson H. W. Leong🇨🇳 · Anupreeta More🇮🇳 · Otto A. Hannuksela🇨🇳 · Tjonnie G. F. Li🇨🇳

    Since the first detection of gravitational waves in 2015, gravitational-wave astronomy has emerged as a rapidly advancing field that holds great potential for studying the cosmos, from probing the properties of black holes to testing the limits of our current understanding of gravity. One important aspect of gravitational-wave astronomy is the phenomenon of gravitational lensing, where massive intervening objects can bend and magnify gravitational waves, providing a unique way to probe the distribution of matter in the universe, as well as finding applications to fundamental physics, astrophysics, and cosmology. However, current models for gravitational-wave millilensing - a specific form of lensing where small-scale astrophysical objects can split a gravitational wave signal into multiple copies - are often limited to simple isolated lenses, which is not realistic for complex lensing scenarios. In this paper, we present a novel phenomenological approach to incorporate millilensing in data analysis in a model-independent fashion. Our approach enables the recovery of arbitrary lens configurations without the need for extensive computational lens modeling, making it a more accurate and computationally efficient tool for studying the distribution of matter in the universe using gravitational-wave signals. When gravitational-wave lensing observations become possible, our method can provide a powerful tool for studying complex lens configurations, including dark matter subhalos and MACHOs.

    ↳ gr-qcastro-ph.HEhep-phMNRAS(2023)·54 citations
32. 32*

    Multi-frequency test of dark matter annihilation into long-lived particles in Sirius

    Yu-Xuan Chen🇨🇳 · Lei Zu🇨🇳 · Zi-Qing Xia🇨🇳 · Yue-Lin Sming Tsai🇨🇳 · Yi-Zhong Fan🇨🇳

    New long-lived particles produced at the colliders may escape from conventional particle detectors. Using satellites or ground telescopes, we can detect the photons generated from the annihilation of the star-captured dark matter into a pair of long-lived particles. When the propagation length of these long-lived particles surpasses the interplanetary distance between the Sun and Jupiter, it becomes unfeasible to detect such dark matter signals originating from the Sun or Jupiter on Earth. Our analysis of the dark matter-induced photons produced by prompt radiation, inverse Compton scattering, and synchrotron radiation mechanisms reveals that a decay length of about $10^{-3}$ pc for long-lived particles is required for maximum detectability. We investigate the parameters that allow the long-lived particle's lifetime to be consistent with Big Bang nucleosynthesis while also allowing it to escape the confines of our solar system. The Sirius system is proposed as a promising target for the indirect detection of such long-lived particles. Utilizing the prompt, inverse Compton scattering, and synchrotron radiation, upper limits on the dark matter-proton spin-independent and spin-dependent cross section are estimated with the Fermi-LAT null-signal observation and the capabilities of the upcoming Square Kilometre Array radio telescope.

    ↳ astro-ph.HEhep-phJCAP(2023)·8 citations
33. 33*

    Transverse-Momentum-Dependent Wave Functions of Pion from Lattice QCD

    Min-Huan Chu🇨🇳 · Jin-Chen He🇨🇳 · Jun Hua🇨🇳 · Jian Liang🇨🇳 · Xiangdong Ji🇺🇸 · Andreas Schafer🇩🇪 · Hai-Tao Shu🇩🇪 · Yushan Su🇺🇸 · Ji-Hao Wang🇨🇳 · Wei Wang🇨🇳 · Yi-Bo Yang🇨🇳 · Jun Zeng🇨🇳 · Jian-Hui Zhang🇨🇳 · Qi-An Zhang🇨🇳

    We present a first lattice QCD calculation of the transverse-momentum-dependent wave functions (TMDWFs) of the pion using large-momentum effective theory. Numerical simulations are based on one ensemble with 2+1+1 flavors of highly improved staggered quarks action with lattice spacing $a=0.121$~fm from the MILC Collaboration, and one with 2 +1 flavor clover fermions and tree-level Symanzik gauge action generated by the CLS Collaboration with $a=0.098$~fm. As a key ingredient, the soft function is first obtained by incorporating the one-loop perturbative contributions and a proper normalization. Based on this and the equal-time quasi-TMDWFs simulated on the lattice, we extract the light-cone TMDWFs. The results are comparable between the two lattice ensembles and a comparison with phenomenological parametrization is made. Our studies provide a first attempt of $ab$ $initio$ calculation of TMDWFs which will eventually lead to crucial theory inputs for making predictions for exclusive processes under QCD factorization.

    ↳ hep-lathep-phPRD(2024)·49 citations
34. 34*

    Bubble expansion at strong coupling

    Li Li🇨🇳 · Shao-Jiang Wang🇨🇳 · Zi-Yan Yuwen🇨🇳

    The cosmological first-order phase transition (FOPT) can be of strong dynamics but with its bubble wall velocity difficult to be determined due to lack of detailed collision terms. Recent holographic numerical simulations of strongly coupled theories with a FOPT prefer a relatively small wall velocity linearly correlated with the phase pressure difference between false and true vacua for a planar wall. In this Letter, we have analytically revealed the non-relativistic limit of a planar/cylindrical/spherical wall expansion of a bubble strongly interacting with the thermal plasma. The planar-wall result reproduces the linear relation found previously in the holographic numerical simulations. The results for cylindrical and spherical walls can be directly tested in future numerical simulations. Once confirmed, the bubble wall velocity for a strongly coupled FOPT can be expressed purely in terms of the hydrodynamics without invoking the underlying microphysics.

    ↳ hep-thastro-ph.COhep-phPRD(2023)·32 citations
35. 35*

    Fayet-Iliopoulos D-Term in Non-Supersymmetric Heterotic String Orbifolds

    Alonzo R. Diaz Avalos🇬🇧 · Alon E. Faraggi🇬🇧 · Viktor G. Matyas🇬🇧 · Benjamin Percival🇬🇧

    The Fayet-Iliopoulos $D$-term is a common feature in $\mathcal{N}=1$ string vacua that contain an anomalous $U(1)$ gauge symmetry, and arises from a one--loop diagram in string perturbation theory. The same diagram is generated in string vacua in which supersymmetry is broken directly at the string scale, either via spontaneous Scherk-Schwarz breaking, in which case the gravitino mass is determined by the radius of the circle used in the Scherk-Schwarz mechanism, or via explicit supersymmetry breaking by the GSO projections. We analyse the resulting would-be Fayet-Illiopoulos $D$-term in the non-supersymmetric string vacua and its contribution to the vacuum energy. A numerical estimate in an explicit tachyon-free string-derived model suggests that the would-be $D$-term contribution may uplift the vacuum energy to a positive value.

    ↳ hep-thhep-phEPJC(2023)·17 citations
36. 36*

    Energy of the symmetrization entanglement

    Mehmet Emre Tasgin🇹🇷

    When a measurement is carried out on one of the entangled parties, the second party can extract work owing to the reduction in its entropy. Here we inquire the amount of work/energy corresponding to the symmetrization entanglement of identical particles (bosons) in a condensate. One measures the quantum state of a particular boson which can be performed only under some certain conditions. We learn that the extracted work comes out to be the \textit{complete} thermodynamical energy present in the condensate. %We learn that the work extracted by the remaining part of the condensate is equal to the excitation energy of the measured boson times the thermodynamical probability of being in the excited state, i.e., $\hslash {\omega }_{eg}\times \exp (-\hslash {\omega }_{eg}/k_{B}T)$. We study the phenomenon in an interacting Bose-Einstein condensate. Then, we discuss that the results may also have fundamental implications on the pair creation in QED vacuum.

    ↳ quant-phgr-qchep-ph1 citation
37. 37*

    A Dirac-material-inspired non-linear electrodynamic model

    M. J. Neves🇧🇷 · Patricio Gaete · L. P. R. Ospedal🇧🇷 · J. A. Helayël-Neto🇧🇷

    We propose and study the properties of a non-linear electrodynamics that emerges inspired on the physics of Dirac materials. This new electrodynamic model is an extension of the one-loop corrected non-linear effective Lagrangian computed in the work of ref. [3]. In the particular regime of a strong magnetic and a weak electric field, it reduces to the photonic non-linear model worked out by the authors of ref. [3]. We pursue our investigation of the proposed model by analyzing properties of the permittivity and permeability tensors, the energy-momentum tensor and wave propagation effects in presence of a uniform magnetic background. It is shown that the electrodynamics here presented exhibits the vacuum birefringence phenomenon. Subsequently, we calculate the lowest-order modifications to the interaction energy, considering still the presence of a uniform external magnetic field. Our analysis is carried out within the framework of the gauge-invariant but path-dependent variables formalism. The calculation reveals a screened Coulomb-like potential with an effective electric charge that runs with the external magnetic field but, as expected for Dirac-type materials, the screening disappears whenever the external magnetic field is switched off.

    ↳ cond-mat.mtrl-scihep-phhep-thphysics.opticsJ.Phys.A(2023)·7 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.