Thu·Dec 14, 2023Thursday·December 14, 2023

1. 01*

   Electroweak Scattering at the Muon Shot

   Tao Han🇺🇸 · Da Liu🇺🇸 · Ian Low🇺🇸 · Xing Wang🇺🇸

   It has long been recognized that the scattering of electroweak particles at very high energies is dominated by vector boson fusion, which probes the origin of electroweak symmetry breaking and offers a unique window into the ultraviolet regime of the SM. Previous studies assume SM-like couplings and rely on the effective $W$ approximation (or electroweak parton distribution), whose validity is well-established within the SM but not yet studied in the presence of anomalous Higgs couplings. In this work, we critically examine the electroweak production of two Higgs bosons in the presence of anomalous $VVh$ and $VVhh$ couplings. We compute the corresponding helicity amplitudes and compare the cross section results in the effective $W$ approximation with the full fixed-order calculation. In particular, we identify two distinct classes of anomalous Higgs couplings, whose effects are not captured by vector boson fusion and effective $W$ approximation. Such very high energy electroweak scatterings can be probed at the Muon Shot, a multi-TeV muon collider upon which we base our study, although similar considerations apply to other high energy colliders.

   hep-phhep-exPRD(2024)·14 citations
2. 02*

   Appraising constrained second-order power corrections in HQET with ${\Lambda }_b\to {\Lambda }_{c}l\nu$

   Florian U. Bernlochner🇩🇪 · Michele Papucci🇺🇸 · Dean J. Robinson🇺🇸

   We derive the ${\Lambda }_b\to {\Lambda }_c$ form factors for the Standard Model and beyond at second order in Heavy Quark Effective Theory (HQET), applying the recently-proposed Residual Chiral Expansion (RCE) to reduce the set of unknown subsubleading hadronic functions to a single, highly-constrained function, that is fully determined by hadron mass parameters at zero recoil. We fit a form factor parametrization based on these results to all available Lattice QCD (LQCD) predictions and experimental data. We find that the constrained and predictive structure of the form factors under the RCE is in excellent agreement with LQCD predictions and experimental data, as well as prior HQET-based fits.

   hep-phPRD(2025)·6 citations
3. 03*

   The Right-Handed Slepton Bulk Regions for Dark Matter in the Generalized Minimal Supergravity (GmSUGRA)

   Imtiaz Khan🇨🇳 · Waqas Ahmed🇨🇳 · Tianjun Li🇨🇳 · Shabbar Raza🇵🇰

   We study the light right-handed slepton bulk regions for dark matter from the Generalized Minimal Supergravity (GmSUGRA) in the Minimal Supersymmetric Standard Model (MSSM). In our comprehensive numerical studies, we show that ${\mathcal{R}}_{\tilde{\varphi }}\gtrsim 10\%$ is a conservative criteria to formulate bulk region, where ${\mathcal{R}}_{\tilde{\varphi }}\equiv (m_{\tilde{\varphi }}-m_{{\tilde{\chi }}_1^0})/m_{{\tilde{\chi }}_1^0}$. For right-handed stau as the Next to the Lightest Supersymmetric Partcile (NLSP), we find a large viable parameter space, consistent with the current LHC constraints, Planck2018 dark matter relic density bounds, and direct bounds on neutralino-nucleons scattering cross-section that naturally supports the right-handed stau bulk regions for dark matter. In particular, the upper bounds on the masses of the Lightest Supersymmetric Particle (LSP) neutralino and right-handed stau are about 120.4 GeV and 138 GeV, respectively. This bulk region may be beyond the current LHC reach and could be probed at LUX-ZEPLIN, a next-generation dark matter direct detection experiment, the Future Circular Collider (FCC-ee) at CERN, and the Circular Electron Positron Collider (CEPC). However, the scenario with the right-handed selectron as the NLSP is excluded by the LHC supersymmetry searches.

   hep-phPRD(2024)·5 citations
4. 04*

   A new understanding of nuclei spectra properties with propagation model

   Xu-Lin Dong🇨🇳 · Yu-Hua Yao🇨🇳 · Yi-Qing Guo🇨🇳 · Shu-Wang Cui🇨🇳

   The AMS-02 experiment has observed new properties of primary cosmic rays (CRs) categorized into two groups: He-C-O-Fe and Ne-Mg-Si-S, which are independent of CR propagation. In this study, we investigate the unexpected properties of these nuclei using a spatial propagation model. All nuclei spectra are accurately reproduced and separated into primary and secondary contributions. Our findings include: 1. Primary CR spectra are identical. 2. Our calculations align with AMS-02 results for primary-dominated nuclei within a 10\% difference, but show significant discrepancies for the secondary-dominated nuclei. 3. The primary element abundance is presented for the first time. We anticipate that the DAMPE and future HERD experiments will provide observations of nuclei spectra above TeV energy.

   hep-phastro-ph.HE0 citations
5. 05*

   Logarithmic EW corrections at one-loop

   Jonas M. Lindert🇬🇧 · Lorenzo Mai🇬🇧

   We present a fully automated implementation of next-to-leading order electroweak (NLO EW) corrections in the logarithmic approximation in OpenLoops. For energies above the electroweak scale NLO EW corrections are logarithmically enhanced and in tails of kinematic distributions of crucial LHC processes yield correction factors of several tens of percent. The implementation of the logarithmic Sudakov EW approximation in the amplitude generator OpenLoops is fully general, largely model independent, it supports the computation of EW corrections to resonant processes, and it is suitable for extensions to the two-loop NNLO EW level. The implementation is based on an efficient representation of the logarithmic approximation in terms of an effective vertex approach. Investigating a set of representative LHC processes we find excellent agreement between the logarithmic approximation and full one-loop results in observables where the assumptions of the EW Sudakov approximation are fulfilled.

   hep-phhep-exEPJC(2024)·19 citations
6. 06*

   Gluon Wigner distributions in a light-cone spectator model

   Chentao Tan🇨🇳 · Zhun Lu🇨🇳

   We study the gluon Wigner distributions of the proton which are the phase-space distributions containing the most general one-parton information. Using the proton wave functions deduced from a light-cone spectator model that contains the gluonic degree of freedom, we calculate the Wigner distributions of the unpolarized and longitudinally polarized gluon inside the unpolarized/longitudinally polarized proton via the Fock-state overlap representation, respectively. We present the numerical results of the transverse Wigner distributions in which the longitudinal momentum fraction is integrated out. The mixed Wigner distributions as functions of $b_y$ and $k_x$ are also presented. We also provide the canonical gluon orbital angular momentum and spin-orbit correlations deduced from the gluon Wigner distribution.

   hep-phEPJC(2025)·7 citations
7. 07*

   Theories Without Models: Uncontrolled Idealizations in Particle Physics

   Antonis Antoniou🇩🇪 · Karim P. Y. Thébault🇬🇧

   The perturbative treatment of realistic quantum field theories, such as quantum electrodynamics, requires the use of mathematical idealizations in the approximation series for scattering amplitudes. Such mathematical idealisations are necessary to derive empirically relevant models from the theory. Mathematical idealizations can be either controlled or uncontrolled, depending on whether current scientific knowledge can explain whether the effects of the idealization are negligible or not. Drawing upon negative formal results in asymptotic analysis (failure of Borel summability) and renormalization group theory (failure of asymptotic safety), we argue that the mathematical idealizations applied in perturbative quantum electrodynamics should be understood as uncontrolled. This, in turn, leads to the problematic conclusion that such theories do not have theoretical models in the standard understanding of this term. The existence of unquestionable empirically successful theories without theoretical models has significant implications both for our understanding of the theory-model relationship in physics and the concept of empirical adequacy.

   hep-phhep-thphysics.hist-phSynthese(2025)·0 citations
8. 08*

   Precise Estimate of Charged Higgsino/Wino Decay Rate

   Masahiro Ibe🇯🇵 · Yuhei Nakayama🇯🇵 · Satoshi Shirai🇯🇵

   Higgsinos and Winos in the supersymmetric Standard Model are prime candidates for dark matter due to their weakly interacting nature. The mass differences between their charged components (charginos) and neutral components (neutralinos) become degenerate when other superparticles are heavy, resulting in long-lived charginos. In the case of the Winos, the mass difference is approximately 160 MeV across a wide range of the parameter space. Consequently, the chargino decays into the lightest neutralino, emitting a single charged pion. For Higgsinos, however, mass differences ranging from O(0.1) GeV to O(1) GeV are possible, leading to a variety of decay channels. In this paper, we extend our previous analysis of Wino decay to the chargino with a larger mass difference. We emphasize characterizing its decay signatures through leptonic and hadronic modes. By utilizing the latest experimental data, we perform a comprehensive study of the decay rate calculations incorporating these hadronic modes to determine the impact on the predicted chargino lifetime. Additionally, we conduct next-to-leading order (NLO) calculations for the leptonic decay modes. Our NLO results can be applied to the case of more general fermionic electroweak multiplets, e.g., quintuplet dark matter.

   hep-phhep-exJHEP(2024)·19 citations
9. 09*

   Scotogenic generation of realistic neutrino mixing with D5

   Soumita Pramanick🇮🇳

   A mechanism of radiative generation of realistic neutrino mixing at one-loop level with $D5\times Z_2$ is presented in this paper. The process is demonstrated in two set-ups using $D5\times Z_2$ symmetry viz. Model 1 and Model 2. Two right-handed neutrinos are present in both the models. In both Model 1 and Model 2, when mixing between these two right-handed neutrinos are maximal, one can produce the form of the left-handed Majorana neutrino mass matrix corresponding to ${\theta }_{13}=0$, ${\theta }_{23}=\pi /4$ and any value of ${\theta }_{12}^0$ associated with Tribimaximal (TBM), Bimaximal (BM), Golden Ratio (GR) or other mixings. Small shift from maximal mixing between the two right-handed neutrino states can generate non-zero ${\theta }_{13}$, deviation of ${\theta }_{23}$ from $\pi /4$ and corrections to the solar mixing ${\theta }_{12}$ in one step for both Model 1 and Model 2. In both the models, two $Z_2$ odd inert $SU(2{)}_L$ doublet scalars are present. The lightest between these two scalars can be a viable dark matter candidate for both Model 1 and Model 2.

   hep-ph1 citation
10. 10*

    Has Telescope Array Discovered Electroweak Monopole?

    Y.M. Cho🇰🇷 · Franklin H. Cho🇰🇷

    We propose the ultra high energy cosmic ray recently detected by Telescope Array to be the electroweak monopole, and present theoretical arguments which support this. This strongly motivates the necessity for the ``cosmic" MoEDAL experiment which could back up our proposal. To confirm this we propose Telescope Array to measure the magnetic charge of the ultra high energy cosmic ray particles with SQUID.

    hep-phPLB(2024)·11 citations
11. 11*

    Two-Loop Master Integrals for Leading-Color $pp\to t\bar{t}H$ Amplitudes with a Light-Quark Loop

    F. Febres Cordero🇺🇸 · G. Figueiredo🇺🇸 · M. Kraus🇲🇽 · B. Page🇨🇭 · L. Reina🇺🇸

    We compute the two-loop master integrals for leading-color QCD scattering amplitudes including a closed light-quark loop in $t\bar{t}H$ production at hadron colliders. Exploiting numerical evaluations in modular arithmetic, we construct a basis of master integrals satisfying a system of differential equations in $ϵ$-factorized form. We present the analytic form of the differential equations in terms of a minimal set of differential one-forms. We explore properties of the function space of analytic solutions to the differential equations in terms of iterative integrals which can be exploited for studying the analytic form of related scattering amplitudes. Finally, we solve the differential equations using generalized series expansions to numerically evaluate the master integrals in physical phase space. As the first computation of a set of two-loop seven-scale master integrals, our results provide valuable input for analytic studies of scattering amplitudes in processes involving massive particles and a large number of kinematic scales.

    hep-phhep-thJHEP(2024)·60 citations
12. 12*

    Quantum tachyonic preheating, revisited

    Anders Tranberg🇳🇴 · Gerhard Ungersbäck🇳🇴

    In certain models of inflation, the postinflationary reheating of the Universe is not primarily due to perturbative decay of the inflaton field into particles, but proceeds through a tachyonic instability. In the process, long-wavelength modes of an unstable field, which is often distinct from the inflaton itself, acquire very large occupation numbers, which are subsequently redistributed into a thermal equilibrium state. We investigate this process numerically through quantum real-time lattice simulations of the Kadanoff-Baym equation, using a 1/N-NLO truncation of the 2PI-effective action. We identify the early-time maximum occupation number, the "classical" momentum range, the validity of the classical approximation and the effective IR temperature, and study the kinetic equilibration of the system and the equation of state.

    hep-phastro-ph.COhep-latJHEP(2024)·6 citations
13. 13*

    Geometrical Interpretation of Neutrino Oscillation with decay

    Rajrupa Banerjee (IIT Bhilai)🇮🇳 · Kiran Sharma (IIT Bhilai, KIT Germany)🇮🇳 · Sudhanwa Patra (IIT Bhilai)🇮🇳 · Prasanta K. Panigrahi (IISER Kolkata)🇮🇳

    The geometrical representation of two-flavor neutrino oscillation represents the neutrino's flavor eigenstate as a magnetic moment-like vector that evolves around a magnetic field-like vector that depicts the Hamiltonian of the system. In the present work, we demonstrate the geometrical interpretation of neutrino in a vacuum in the presence of decay, which transforms this circular trajectory of neutrino into a helical track that effectively makes the neutrino system mimic a classical damped driven oscillator. We show that in the absence of the phase factor $\xi$ in the decay Hamiltonian, the neutrino exactly behaves like the system of nuclear magnetic resonance(NMR); however, the inclusion of the phase part introduces a $CP$ violation, which makes the system deviate from NMR. Finally, we make a qualitative discussion on under-damped, critically-damped, and over-damped scenarios geometrically by three different diagrams. In the end, we make a comparative study of geometrical picturization in vacuum, matter, and decay, which extrapolates the understanding of the geometrical representation of neutrino oscillation in a more straightforward way.

    hep-ph4 citations
14. 14*

    Spin relaxation rate for baryons in thermal pion gas

    Yoshimasa Hidaka🇯🇵 · Masaru Hongo🇯🇵 · Mikhail Stephanov🇺🇸 · Ho-Ung Yee🇺🇸

    We study the relaxation dynamics of the spin polarization of baryons (nucleon and $\Lambda$-baryon), in a thermal pion gas as a simple model of the hadronic phase of the QCD plasma produced in relativistic heavy-ion collisions. For this purpose, we formulate the quantum kinetic theory for the spin density matrix of baryons in the leading order of the gradient expansion. Considering the baryon-pion elastic scattering processes as the dominant interaction between baryons and thermal pions, we compute the spin relaxation rate of nucleons and $\Lambda$-baryons in a pion gas up to temperature 200 MeV. In the case of nucleons, we evaluate the spin relaxation rate in the $s$-channel resonance approximation, based on the known experimental data on $\Delta$-resonances. We also estimate the spin relaxation rate for $\Lambda$-baryons, based on experimental inputs and theoretical models for the low-energy $\Lambda$$\pi$ scattering, including the chiral perturbation theory.

    hep-phhep-thnucl-thPRC(2024)·25 citations
15. 15*

    On low-scale baryogenesis from three-body decays

    F. Domínguez🇪🇸 · J. Racker🇦🇷

    Baryogenesis at the TeV scale from CP-violating decays of a massive particle requires some way to avoid the washouts from processes closely related to the existence of CP violation. It has been proposed that one way can be baryogenesis from three-body decays (instead of two-body decays). In this work we revisit this statement and show that, similarly to two-body-decay models, successful baryogenesis from three-body decays requires that the mass of the decaying particle be well above 10-100 TeV unless some other mechanism to avoid washouts is implemented.

    hep-phPRD(2024)·1 citation
16. 16*

    Exploring the conformal transition from above and below

    Alex Pomarol🇪🇸 · Lindber Salas🇪🇸

    We consider conformal transitions arising from the merging of IR and UV fixed points, expected to occur in QCD with a large enough number of flavors. We study the smoothness of physical quantities across this transition, being mostly determined by the logarithmic breaking of conformal invariance. We investigate this explicitly using holography where approaching the conformal transition either from outside or inside the conformal window (perturbed by a mass term) is characterized by the same dynamics. The mass of spin-1 mesons and $F_{\pi }$ are shown to be continuous across the transition, as well as the dilaton mass. This implies that the lightness of the dilaton cannot be a consequence of the spontaneous breaking of scale invariance when leaving the conformal window. Our analysis suggests that the light scalar observed in QCD lattice simulations is a $q\bar{q}$ meson that becomes light since the $q\bar{q}$-operator dimension reaches its minimal value.

    hep-phhep-lathep-thJHEP(2024)·13 citations
17. 17*

    Nonrelativistic nuclear reduction for tensor couplings in dark matter direct detection and $\mu \to e$ conversion

    Ayala Glick-Magid🇺🇸

    The nonrelativistic effective field theory (NRET) is widely used in dark matter direct detection and charged-lepton flavor violation studies through $\mu \to e$ conversion. However, existing literature has not fully considered tensor couplings. This study fills this gap by utilizing an innovative tensor decomposition method, extending NRET to incorporate previously overlooked tensor interactions. This development is expected to have a significant impact on ongoing experiments seeking physics beyond the Standard Model and on our understanding of the new-physics interactions. Notably, we identify additional operators in $\mu \to e$ conversion that are absent in scalar and vector couplings. To support further research and experimental analyses, comprehensive tables featuring tensor matrix elements and their corresponding operators are provided.

    hep-phnucl-exnucl-thPRD(2024)·5 citations
18. 18*

    Leptogenesis in the minimal flipped $SU(5)$ unification

    Renato Fonseca🇪🇸 · Michal Malinský🇨🇿 · Václav Miřátský🇨🇿 · Martin Zdráhal🇨🇿

    We study the prospects of thermal leptogenesis in the framework of the minimal flipped $SU(5)$ unified model in which the RH neutrino mass scale emerges as a two-loop effect. Despite its strong suppression with respect to the unification scale which tends to disfavor leptogenesis in the standard Davidson-Ibarra regime (and a notoriously large washout of the $N_1$-generated asymmetry owing to a top-like Yukawa entry in the Dirac neutrino mass matrix) the desired ${\eta }_B\sim 6\times 10^{-10}$ can still be attained in several parts of the parameter space exhibiting interesting baryon and lepton number violation phenomenology. Remarkably enough, in all these regions the mass of the lightest LH neutrino is so low that it yields $m_{\beta }\lesssim 0.03$ eV for the effective neutrino mass measured in beta-decay, i.e., an order of magnitude below the design sensitivity limit of the KATRIN experiment. This makes the model potentially testable in the near future.

    hep-phPRD(2024)·3 citations
19. 19*

    The Cosmological Dynamics of String Theory Axion Strings

    Joshua N. Benabou🇺🇸 · Quentin Bonnefoy🇺🇸 · Malte Buschmann🇺🇸 · Soubhik Kumar🇺🇸 · Benjamin R. Safdi🇺🇸

    The quantum chromodynamics (QCD) axion may solve the strong CP problem and explain the dark matter (DM) abundance of our Universe. The axion was originally proposed to arise as the pseudo-Nambu Goldstone boson of global $\mathrm{U}(1{)}_{\mathrm{PQ}}$ Peccei-Quinn (PQ) symmetry breaking, but axions also arise generically in string theory as zero modes of higher-dimensional gauge fields. In this work we show that string theory axions behave fundamentally differently from field theory axions in the early Universe. Field theory axions may form axion strings if the PQ phase transition takes place after inflation. In contrast, we show that string theory axions do not generically form axion strings. In special inflationary paradigms, such as D-brane inflation, string theory axion strings may form; however, their tension is parametrically larger than that of field theory axion strings. We then show that such QCD axion strings overproduce the DM abundance for all allowed QCD axion masses and are thus ruled out, except in scenarios with large warping. A loop-hole to this conclusion arises in the axiverse, where an axion string could be composed of multiple different axion mass eigenstates; a heavier eigenstate could collapse the network earlier, allowing for the QCD axion to produce the correct DM abundance and also generating observable gravitational wave signals.

    hep-phastro-ph.COhep-thPRD(2024)·40 citations
20. 20*

    Using the effective weak mixing angle as an input parameter in SMEFT

    Anke Biekötter🇩🇪 · Benjamin D. Pecjak🇬🇧 · Tommy Smith🇬🇧

    We implement electroweak renormalisation schemes involving the effective weak mixing angle to NLO in Standard Model Effective Field Theory (SMEFT). After developing the necessary theoretical machinery, we analyse a select set of electroweak precision observables in such input schemes. An attractive feature is that large corrections from top-quark loops appearing in other schemes are absorbed into the definition of the effective weak mixing angle. On the other hand, the renormalisation condition which achieves this involves a large number of flavour-specific SMEFT couplings between the $Z$ boson and charged leptons, motivating simple flavour assumptions such as minimal flavour violation for practical applications. The results of this paper provide a valuable new component for estimating systematic uncertainties in SMEFT fits by performing analyses in multiple input schemes.

    hep-phJHEP(2024)·10 citations
21. 21*

    Integrating Particle Flavor into Deep Learning Models for Hadronization

    Jay Chan🇺🇸 · Xiangyang Ju🇺🇸 · Adam Kania🇵🇱 · Benjamin Nachman🇺🇸 · Vishnu Sangli🇺🇸 · Andrzej Siodmok🇵🇱

    Hadronization models used in event generators are physics-inspired functions with many tunable parameters. Since we do not understand hadronization from first principles, there have been multiple proposals to improve the accuracy of hadronization models by utilizing more flexible parameterizations based on neural networks. These recent proposals have focused on the kinematic properties of hadrons, but a full model must also include particle flavor. In this paper, we show how to build a deep learning-based hadronization model that includes both kinematic (continuous) and flavor (discrete) degrees of freedom. Our approach is based on Generative Adversarial Networks and we show the performance within the context of the cluster hadronization model within the Herwig event generator.

    hep-phhep-exphysics.data-anPRD(2025)·17 citations
22. 22*

    Evaporating Kerr black holes as probes of new physics

    Marco Calzà🇵🇹 · João G. Rosa🇵🇹

    In the string axiverse scenario, primordial black holes (PBHs) can sustain non-negligible spin parameters as they evaporate. We show that tracking both the mass and spin evolution of a PBH in its final hour can yield a purely gravitational probe of new physics beyond the TeV scale, allowing one to determine the number of new scalars, fermions, vector bosons, and spin-3/2 particles. Furthermore, we propose a multi-messenger approach to accurately measure the mass and spin of a PBH from its Hawking photon and neutrino primary emission spectra, which is independent of putative interactions between the new degrees of freedom and the Standard Model particles, as well as from the Earth-PBH distance.

    hep-phastro-ph.HEgr-qcJHEP(2025)·17 citations
23. 23*

    Dynamical friction in self-interacting ultralight dark matter

    Noah Glennon🇺🇸 · Nathan Musoke🇺🇸 · Ethan O. Nadler🇺🇸 · Chanda Prescod-Weinstein🇺🇸 · Risa H. Wechsler🇺🇸

    We explore how dynamical friction in an ultralight dark matter (ULDM) background is affected by dark matter self-interactions. We calculate the force of dynamical friction on a point mass moving through a uniform ULDM background with self-interactions, finding that the force of dynamical friction vanishes for sufficiently strong repulsive self-interactions. Using the pseudospectral solver $\text{UltraDark.jl}$, we show with simulations that reasonable values of the ULDM self-interaction strength and particle mass cause $\mathcal{O}(1)$ differences in the acceleration of an object like a supermassive black hole (SMBH) traveling near the center of a soliton, relative to the case with no self-interactions. For example, repulsive self-interactions with $\lambda =10^{-90}$ yield a deceleration due to dynamical friction $\approx 70\%$ smaller than a model with no self-interactions. We discuss the observational implications of our results for SMBHs near soliton centers and for massive satellite galaxies falling into ultralight axion halos and show that outcomes are dependent on whether a self-interaction is present or not.

    ↳ astro-ph.COhep-phPRD(2024)·22 citations
24. 24*

    Axion String Source Modelling

    Amelia Drew🇬🇧 · Tomasz Kinowski🇬🇧 · E. P. S. Shellard🇬🇧

    In this paper, we perform an investigation into the effect of the string radius of curvature $R_{\mathrm{Gaussian}}$ on the magnitude and relative magnitude of the massive and massless radiation from axion (global) string configurations, motivated by qualitative observations from string network simulations. We construct initial conditions from travelling wave solutions on a global string for two colliding Gaussians, performing parameter scans over amplitude $A$ and standard deviation ${\sigma }_{\mathrm{d}}$. We show that the energy emitted via massless radiation obeys a power law $E_{\mathrm{massless}}\propto A^{\gamma }$, where the coefficient $\gamma$ depends on the curvature regime. Massive radiation is exponentially suppressed approximately as $E_{\mathrm{massive}}\propto e^{-\zeta R_{\mathrm{Gaussian}}}$ in the quasi-linear regime ${\sigma }_{\mathrm{d}}\gg \delta$ and exhibits power-law decay $E_{\mathrm{massive}}\propto (R_{\mathrm{Gaussian}}{)}^{-\gamma }$ in the nonlinear regime where ${\sigma }_{\mathrm{d}}\lesssim 2\delta$, with different $\gamma$ in different regimes of $R_{\mathrm{Gaussian}}$. In certain regions of the nonlinear regime, massive particle radiation comprises up to 50% of the total energy emitted. Drawing on a known parallel between axion radiation from global strings and gravitational radiation from Abelian-Higgs strings, this suggests that massive particle radiation channel may become of equal significance to the massless (gravitational) channel for nonlinear burst signals where $R<{\sigma }_{\mathrm{d}}$, unless we are in the regime where additional loops are generated. We also estimate the spectral index $q$ of the axion radiation for different amplitudes, showing that a higher proportion of radiation is emitted in high frequency modes as the curvature increases, bounded by $q\gtrsim 1$ for the configurations studied.

    ↳ astro-ph.COgr-qchep-phPRD(2024)·23 citations
25. 25*

    Lorentz invariance violation and the CPT-odd electromagnetic response of a tilted anisotropic Weyl semimetal

    Andrés Gómez🇲🇽 · R. Martínez von Dossow🇲🇽 · A. Martín-Ruiz🇲🇽 · Luis F. Urrutia🇲🇽

    We derive the electromagnetic response of a particular fermionic sector in the minimal QED contribution to the Standard Model Extension (SME), which can be physically realized in terms of a model describing a tilted and anisotropic Weyl semimetal (WSM). The contact is made through the identification of the Dirac-like Hamiltonian resulting from the SME with that corresponding to the WSM in the linearized tight-binding approximation. We first calculate the effective action by computing the non-perturbative vacuum polarization tensor using thermal field theory techniques, focusing upon the corrections at finite chemical potential and zero temperature. Next, we confirm our results by a direct calculation of the anomalous Hall current within a chiral kinetic theory approach. In an ideal Dirac cone picture of the WSM (isotropic and non-tilted) such response is known to be governed by axion electrodynamics, with the space-time dependent axion angle $\Theta (\mathbf{r},t)=2(\mathbf{b}\cdot \mathbf{r}-b_{0}t)$, being $2\mathbf{b}$ and $2b_0$ the separation of the Weyl nodes in momentum and energy, respectively. In this paper we demonstrate that the node tilting and the anisotropies induce novel corrections at a finite density which however preserve the structure of the axionic field theory. We apply our results to the ideal Weyl semimetal ${\mathrm{EuCd}}_2{\mathrm{As}}_2$ and to the highly anisotropic and tilted monopnictide $\mathrm{TaAs}$.

    ↳ hep-thcond-mat.mes-hallhep-phPRD(2024)·18 citations
26. 26*

    Theoretical developments on the initial state in relativistic particle collisions

    Heikki Mäntysaari🇫🇮

    We discuss recent progress towards developing accurate initial state descriptions for heavy ion collisions focusing on weak coupling based approaches, that enable one to constrain the high-energy structure of nuclei from deep inelastic scattering or proton-nucleus collisions. We review recent developments to determine the event-by-event fluctuating nuclear geometry, to describe gluon saturation phenomena at next-to-leading order accuracy, and to include longitudinal dynamics to the initial state descriptions.

    ↳ nucl-thhep-phEPJ Web Conf.(2024)·2 citations
27. 27*

    Stealth dark matter spectrum using LapH and Irreps

    Richard C. Brower🇺🇸 · Christopher Culver🇬🇧 · Kimmy K. Cushman🇺🇸 · George T. Fleming🇺🇸 · Anna Hasenfratz🇺🇸 · Dean Howarth🇺🇸 · James Ingoldby🇬🇧 · Xiao Yong Jin🇺🇸 · Graham D. Kribs🇺🇸 · Aaron S. Meyer🇺🇸 · Ethan T. Neil🇺🇸 · James C. Osborn🇺🇸 and 8 other authors

    We present non-perturbative lattice calculations of the low-lying meson and baryon spectrum of the SU(4) gauge theory with fundamental fermion constituents. This theory is one instance of stealth dark matter, a class of strongly coupled theories, where the lowest mass stable baryon is the dark matter candidate. This work constitutes the first milestone in the program to study stealth dark matter self-interactions. Here, we focus on reducing excited state contamination in the single baryon channel by applying the Laplacian Heaviside method, as well as projecting our baryon operators onto the irreducible representations of the octahedral group. We compare our resulting spectrum to previous work involving Gaussian smeared non-projected operators and find good agreement with reduced statistical uncertainties. We also present the spectrum of the low-lying odd-parity baryons for the first time.

    ↳ hep-lathep-phPRD(2024)·6 citations
28. 28*

    Low-Scale Inflationary Magnetogenesis without Baryon Isocurvature Problem

    Kazuki Yanagihara🇯🇵 · Fumio Uchida🇯🇵 · Tomohiro Fujita🇯🇵 · Shinji Tsujikawa🇯🇵

    Primordial magnetogenesis is an intriguing possibility to explain the origin of intergalactic magnetic fields (IGMFs). However, the baryon isocurvature problem has recently been pointed out, ruling out all magnetogenesis models operating above the electroweak scale. In this letter, we show that lower-scale inflationary scenarios with a Chern-Simons coupling can evade this problem. We propose concrete inflationary models whose reheating temperatures are lower than the electroweak scale and numerically compute the amount of magnetic fields generated during inflation and reheating. We find that, for lower reheating temperatures, the magnetic helicity decreases significantly. It is also possible to generate fully helical magnetic fields by modifying the inflaton potential. In both cases, the produced magnetic fields can be strong enough to explain the observed IGMFs, while avoiding the baryon isocurvature problem.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2024)·12 citations
29. 29*

    Elliptic and triangular flow of light nuclei in Au+Au collisions in the BES-II energies using the STAR detector

    Rishabh Sharma🇮🇳

    Light nuclei might be formed in heavy-ion collisions by the coalescence of produced (anti-)nucleons or transported nucleons. Due to their low binding energies, they are more likely to form at later stages of the hadronic fireball. In this proceedings, we report the transverse momentum and centrality dependence of elliptic ($v_2$) and triangular ($v_3$) flow of $d$, $t$, and ${}^3$He in Au+Au collisions at $\sqrt{s_{NN}}$ = 14.6 -- 54.4 GeV. The mass number scaling of $v_2(p_T)$ and $v_3(p_T)$ of light nuclei is discussed. We also report the comparison of $v_2(p_T)$ and $v_3(p_T)$ of light nuclei with a transport-plus-coalescence model calculation.

    ↳ nucl-exhep-exhep-phEPJ Web Conf.(2024)·1 citation
30. 30*

    Non-hydrodynamic response in QCD-like plasma

    Weiyao Ke🇨🇳 · Yi Yin🇨🇳

    Quark-gluon plasma's (QGP) properties at non-hydrodynamic and non-perturbative regimes remain largely unexplored. Here, we examine the response functions describing how a QGP-like plasma responds to initial energy-momentum disturbance in both static and Bjorken-expanding plasma at non-hydrodynamic gradient using the Boltzmann equation in the relaxation-time approximation (RTA). We show that the resulting response functions are remarkably similar in both static and expanding backgrounds at non-hydrodynamic gradients. While non-hydrodynamic response can not be described by the conventional first-order and second-order theories, its behavior is reasonably captured by the extended version of hydrodynamics proposed by us (arXiv: 2208.01046). The potential sensitivity of the Euclidean correlator to non-hydrodynamic response is also illustrated.

    ↳ nucl-thhep-phhep-thJHEP(2024)·4 citations
31. 31*

    The Milky Way shines in high-energy neutrinos

    Mauricio Bustamante🇩🇰

    The most energetic astrophysical sources in the Milky Way, cosmic accelerators capable of producing high-energy cosmic rays, have resisted discovery for over a century. Up to now, astrophysicists sought these sources mainly by scouring the Galaxy for the gamma rays they are expected to emit. In 2023, the IceCube Neutrino Observatory discovered high-energy neutrinos from the Milky Way, inaugurating a telltale stream of evidence of cosmic-ray production and interaction in the Galaxy.

    ↳ astro-ph.HEhep-exhep-phNature Rev.Phys.(2024)·10 citations
32. 32*

    Efficient parameter inference for gravitational wave signals in the presence of transient noises using temporal and time-spectral fusion normalizing flow

    Tian-Yang Sun🇺🇸 · Chun-Yu Xiong🇺🇸 · Shang-Jie Jin🇺🇸 · Yu-Xin Wang🇺🇸 · Jing-Fei Zhang🇺🇸 · Xin Zhang🇺🇸

    Glitches represent a category of non-Gaussian and transient noise that frequently intersects with gravitational wave (GW) signals, exerting a notable impact on the processing of GW data. The inference of GW parameters, crucial for GW astronomy research, is particularly susceptible to such interference. In this study, we pioneer the utilization of temporal and time-spectral fusion normalizing flow for likelihood-free inference of GW parameters, seamlessly integrating the high temporal resolution of the time domain with the frequency separation characteristics of both time and frequency domains. Remarkably, our findings indicate that the accuracy of this inference method is comparable to traditional non-glitch sampling techniques. Furthermore, our approach exhibits greater efficiency, boasting processing times on the order of milliseconds. In conclusion, the application of normalizing flow emerges as pivotal in handling GW signals affected by transient noises, offering a promising avenue for enhancing the field of GW astronomy research.

    ↳ gr-qcastro-ph.COastro-ph.IMhep-phCPC(2024)·26 citations
33. 33*

    Highly anisotropic lattices for Yang-Mills theory

    Kirill Boguslavski🇦🇹 · Paul Hotzy🇦🇹 · David I. Müller🇦🇹 · Dénes Sexty🇦🇹

    In this conference proceeding, we investigate the physical anisotropy in terms of the temporal and spatial lattice spacings in relation to the bare parameters of SU(2) pure gauge theory using Wilson gradient flow. Anisotropic lattices have a wide range of applications, from thermodynamic calculations in QCD to very recent real-time simulations using the complex Langevin method. We find an almost linear relationship between the bare and renormalized anisotropy. Using a parametrization that includes nonlinear effects and was earlier proposed for SU(3) theory, we obtain a good description of the coupling dependence of the anisotropy with only two fitting parameters. Our observation of an approximately linear relationship and this parametrization should strongly reduce the computational effort of anisotropic lattice calculations in the future.

    ↳ hep-lathep-phPoS(2024)·1 citation
34. 34*

    Updates on the glitching pulsar monitoring campaign performed from IAR

    Ezequiel Zubieta🇦🇷 · Santiago del Palacio🇦🇷 · Federico García🇦🇷 · Susana Beatriz Araujo Furlan · Guillermo Gancio · Carlos Oscar Lousto🇺🇸 · Jorge Ariel Combi

    Pulsars are known for their exceptionally stable rotation. However, this stability can be disrupted by glitches, sudden increases in rotation frequency whose cause is poorly understood. In this study, we present some preliminary results from the pulsar monitoring campaign conducted at the IAR since 2019. We present measurements from timing solution fits of the parameters of five glitches: one glitch in the Vela pulsar, one in PSR J0742-2822, one in PSR J1740-3015, and two mini-glitches in PSR J1048-5832. Finally, we applied the vortex creep model to characterize the inter-glitch period of Vela. However, the preliminary results yielded highly degenerate and loosely constrained parameters.

    ↳ astro-ph.HEhep-ph1 citation
35. 35*

    Revisiting the stochastic QCD axion window: departure from equilibrium during inflation

    Vadim Briaud🇫🇷 · Kenji Kadota🇨🇳 · Shinji Mukohyama🇯🇵 · Alireza Talebian🇮🇷 · Vincent Vennin🇫🇷

    If dark matter is made of QCD axions, its abundance is determined by the vacuum expectation value acquired by the axion field during inflation. The axion is usually assumed to follow the equilibrium distribution arising from quantum diffusion during inflation. This leads to the so-called stochastic window under which the QCD axion can make up all the dark matter. It is characterised by $10^{10.4}\mathrm{GeV}\le f\le 10^{17.2}\mathrm{GeV}$ and $H_{\mathrm{end}}>10^{-2.2}\mathrm{GeV}$, where $f$ is the axion decay constant and $H_{\mathrm{end}}$ is the Hubble expansion rate at the end of inflation. However, in realistic inflationary potentials, we show that the axion never reaches the equilibrium distribution at the end of inflation. This is because the relaxation time of the axion is much larger than the typical time scale over which $H$ varies during inflation. As a consequence, the axion acquires a quasi-flat distribution as long as it remains light during inflation. This leads us to reassessing the stochastic axion window, and we find that $10^{10.3}\mathrm{GeV}\le f\le 10^{14.1}\mathrm{GeV}$ and $H_{\mathrm{end}}>10^{-13.8}\mathrm{GeV}$.

    ↳ astro-ph.COhep-phJCAP(2024)·4 citations
36. 36*

    Early Dark Energy and Dark Photon Dark Matter from Waterfall Symmetry Breaking

    Alireza Talebian🇮🇷

    We investigate a cosmological model wherein a waterfall symmetry breaking occurs during the radiation-dominated era. The model comprises a complex waterfall field, an axion field, and the gauge field (dark photon) generated through a tachyonic instability due to the Chern-Simons interaction. Prior to symmetry breaking, the total energy density incorporates a vacuum energy from the waterfall field, establishing a novel scenario for Early Dark Energy (EDE). Subsequent to the symmetry breaking, the dark photon dynamically acquires mass via the Higgs mechanism, potentially contributing to the dark matter abundance. Hence, our model can simultaneously address the $H_0$ tension and the origin of dark matter.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2024)·7 citations
37. 37*

    Neural networks for boosted di-$\tau$ identification

    Nadav Tamir🇮🇱 · Ilan Bessudo🇮🇱 · Boping Chen🇮🇱 · Hely Raiko🇮🇱 · Liron Barak🇮🇱

    We train several neural networks and boosted decision trees to discriminate fully-hadronic boosted di-$\tau$ topologies against background QCD jets, using calorimeter and tracking information. Boosted di-$\tau$ topologies consisting of a pair of highly collimated $\tau$-leptons, arise from the decay of a highly energetic Standard Model Higgs or Z boson or from particles beyond the Standard Model. We compare the tagging performance for different neural-network models and a boosted decision tree, the latter serving as a simple benchmark machine learning model.

    ↳ hep-exhep-phJINST(2024)·4 citations
38. 38*

    Gluonic evanescent operators: negative-norm states and complex anomalous dimensions

    Qingjun Jin🇨🇳 · Ke Ren🇨🇳 · Gang Yang🇨🇳 · Rui Yu🇨🇳

    In this paper, we build on our previous work to further investigate the role of evanescent operators in gauge theories, with a particular focus on their contribution to violations of unitarity. We develop an efficient method for calculating the norms of gauge-invariant operators in Yang-Mills (YM) theory by employing on-shell form factors. Our analysis, applicable to general spacetime dimensions, reveals the existence of negative norm states among evanescent operators. We also explore the one-loop anomalous dimensions of these operators and find complex anomalous dimensions. We broaden our analysis by considering YM theory coupled with scalar fields and we observe similar patterns of non-unitarity. The presence of negative norm states and complex anomalous dimensions across these analyses provides compelling evidence that general gauge theories are non-unitary in non-integer spacetime dimensions.

    ↳ hep-thhep-phJHEP(2024)·6 citations
39. 39*

    The Cosmological Constant, Dark Matter and the ElectroWeak Scale meet in the Swampland

    Kazem Bitaghsir Fadafan🇮🇷 · Giacomo Cacciapaglia🇫🇷

    The Swampland program, which looks for low energy theories consistent with quantum gravity, has led to the introduction of a dark dimension stemming from the cosmological constant. We show that the same argument leads to the emergence of the electroweak scale, once the dark dimension is realised in a warped background. A second warped extra dimension at the TeV scale is, therefore, postulated, where the long-standing problem of the hierarchy between the electroweak and the Planck scales can be addressed. Furthermore, standard model contributions to the cosmological constant are tamed, together with the gravitational ones. In the emergent holistic picture of gravity and gauge interactions, both Planck and the electroweak scales are emergent from a theory with two fundamental scales: $10^{-2}$ eV and $10^{10}$ GeV, which are of geometric origin and, following the Distance Conjecture, natural. Hence, a bridge is established between the two standard models of particle physics and cosmology.

    ↳ hep-thhep-phJHEP(2025)·3 citations
40. 40*

    Electron and Muon Dynamics in Neutron Stars Beyond Chemical Equilibrium

    Joachim Kopp (CERN and JGU Mainz)🇨🇭 · Toby Opferkuch (UC Berkeley and LBL)🇺🇸

    A neutron star harbors of order $10^{56}$ electrons in its core, and almost the same number of muons, with muon decay prohibited by Pauli blocking. However, as macroscopic properties of the star such as its mass, rotational velocity, or magnetic field evolve over time, the equilibrium lepton abundances (dictated by the weak interactions) change as well. Scenarios where this can happen include spin-down, accretion, magnetic field decay, and tidal deformation. We discuss the mechanisms by which a star disrupted in one of these ways re-establishes lepton chemical equilibrium. In most cases, the dominant processes are out-of-equilibrium Urca reactions, the rates of which we compute for the first time. If, however, the equilibrium muon abundance decreases, while the equilibrium electron abundance increases (or decreases less than the equilibrium muon abundance), outward diffusion of muons plays a crucial role as well. This is true in particular for stars older than about 10,000 yrs whose core has cooled to $\lesssim 20$ keV. The muons decay in a region where Pauli blocking is lifted, and we argue that these decays lead to a flux of $\mathcal{O}$(10 MeV) neutrinos. Realistically, however, this flux will remain undetectable for the foreseeable future.

    ↳ astro-ph.HEhep-phnucl-thJCAP(2024)·1 citation

* 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.