Mon·Mar 25, 2024Monday·March 25, 2024

1. 01*

   Consistent Excesses in the Search for ${\tilde{\chi }}_2^0{\tilde{\chi }}_1^{\pm }$ : Wino/bino vs. Higgsino Dark Matter

   Manimala Chakraborti🇬🇧 · Sven Heinemeyer🇪🇸 · Ipsita Saha🇮🇳

   The quest for supersymmetric (SUSY) particles is among the main search channels currently pursued at the LHC. Particularly, electroweak (EW) particles with masses as low as a few hundred GeV are still viable. Recent searches for the ``golden channel'', $pp\to {\tilde{\chi }}_2^0{\tilde{\chi }}_1^{\pm }\to {\tilde{\chi }}_1^0{Z}^{(\ast )}{\tilde{\chi }}_1^0{W}^{\pm (\ast )}$ show consistent excesses between ATLAS and CMS in the 2~lepton, 3-lepton and mono-jet searches, assuming $m_{{\tilde{\chi }}_2^0}\approx m_{{\tilde{\chi }}_1^{\pm }}\gtrsim 200$ GeV and $\Delta m:=m_{{\tilde{\chi }}_2^0}-m_{{\tilde{\chi }}_1^0}\approx 20$ GeV. This mass configuration arises naturally in SUSY scenarios with wino/bino Dark Matter (DM) or higgsino DM. In these scenarios the lightest supersymmetric particle (LSP), assumed to be the lightest neutralino, as a DM candidate, is in good agreement with the observed limits on the DM content of the universe, as well as with negative results from Direct Detection (DD) experiments. We analyze these two scenarios with respect to the observed excesses, taking into account all relevant experimental constraints. We show that in particular wino/bino DM with different signs of the $SU(2)$ and $U(1)$ soft SUSY-breaking parameters can describe well the experimental excesses, while being in agreement with all other constraints.

   hep-phEPJC(2024)·26 citations
2. 02*

   Flavor composition of supernova neutrinos

   Antonio Capanema🇧🇷 · Yago Porto🇧🇷 · Maria Manuela Saez🇯🇵

   Predicting the flavor composition of neutrinos from supernovae is a challenging task, primarily due to the high neutrino densities at their core. In such an environment, neutrino self-interactions give rise to collective effects that have dramatic yet poorly understood consequences for their flavor evolution. In this paper, however, we show that standard matter effects in the outer layers of supernovae can significantly constrain the flavor composition of the neutrino flux. We assume that, since a large number of neutrinos undergo different evolutions within the core, their state upon entering the MSW-dominated region is affected by decoherence. This assumption simplifies the problem and suggests that the fraction of neutrinos with electron flavor reaching Earth, denoted as $f_{{\nu }_e}$, is constrained to be less than $0.5$ for all energies throughout the emission phase in the case of normal mass ordering. In contrast, for inverted mass ordering, we anticipate neutrinos arriving in near flavor equipartition ($f_{{\nu }_e}\approx 1/3$). These predictions, and consequently their underlying assumptions, could be tested by future observations and may provide valuable insights into the properties of neutrino fluxes emerging from supernovae.

   hep-phastro-ph.HEastro-ph.SRPRD(2025)·10 citations
3. 03*

   Higgs Pair Production in the 2HDM: Impact of Loop Corrections to the Trilinear Higgs Couplings and Interference Effects on Experimental Limits

   S. Heinemeyer🇪🇸 · M. Mühlleitner🇩🇪 · K. Radchenko🇩🇪 · G. Weiglein🇩🇪

   The results obtained at the LHC for constraining the trilinear Higgs self-coupling of the detected Higgs boson at about 125 GeV, ${\lambda }_{hhh}$, via the Higgs pair production process have significantly improved during the last years. We investigate the impact of potentially large higher-order corrections and interference effects on the comparison between the experimental results and the theoretical predictions for the pair production of the 125 GeV Higgs boson at the LHC. We use the theoretical framework of the Two Higgs Doublet Model (2HDM), containing besides the SM-like $\mathcal{C}\mathcal{P}$-even Higgs boson $h$ a second $\mathcal{C}\mathcal{P}$-even Higgs boson $H$, which we assume to be heavier, $m_H>m_h$. We analyze in particular the invariant mass distribution of the two produced Higgs bosons and show that the loop corrections to the trilinear Higgs couplings ${\lambda }_{hhh}$ and ${\lambda }_{hhH}$ as well as interference contributions give rise to important effects both for the differential and the total cross section. We point out the implications for the experimental limits that can be obtained in the 2HDM for the case of the resonant production of the heavy Higgs boson $H$. We emphasize the importance of the inclusion of interference effects between resonant and non-resonant contributions in the experimental analysis for a reliable determination of exclusion bounds for a heavy resonance of an extended Higgs sector.

   hep-phEPJC(2025)·33 citations
4. 04*

   Four-body Semileptonic Decays $B\to D^{\ast }P{\ell }^{+}{\nu }_{\ell }$ with the SU(3) Flavor Symmetry

   Meng-Yuan Wan🇨🇳 · Yuan-Guo Xu🇨🇳 · Qi-Lin Jia🇨🇳 · Yue-Xin Liu🇨🇳 · Yi-Jie Zhang🇨🇳

   We present a complete study of the $B\to D^{\ast }P{\ell }^{+}{\nu }_{\ell }(\ell =e,\mu ,\tau )$ decays with the non-resonant, the charmed axial vector resonant and the charmed tensor resonant contributions by using the SU(3) flavor symmetry. Relevant amplitude relations between different decay modes are obtained by the SU(3) flavor symmetry. We then predict non-measured branching ratios of the $B\to D^{\ast }P{\ell }^{+}{\nu }_{\ell }$ decays with the non-resonant and the charmed resonant contributions by using present experimental data of the $B\to D^{\ast }P{\ell }^{\prime +}{\nu }_{{\ell }^{\prime }}({\ell }^{\prime }=e,\mu )$ decays within $2\sigma$ errors. We have found that $B^{0,+}\to D^{\ast }\eta {\ell }^{+}{\nu }_{\ell }$, $B^{0,+}\to D^{\ast }{\eta }^{\prime }{\ell }^{+}{\nu }_{\ell }$, $B_s^0\to D_s^{\ast }\eta {\ell }^{+}{\nu }_{\ell }$, $B_s^0\to D_s^{\ast }{\eta }^{\prime }{\ell }^{+}{\nu }_{\ell }$ and $B^{0,+}\to D_s^{\ast }K{\ell }^{+}{\nu }_{\ell }$ decays only receive non-resonant contributions. Decays $B_s^0\to D_s^{\ast -}{\pi }^0{\ell }^{+}{\nu }_{\ell }$ only receive the $D_{s1}^{\prime }$ resonant contributions. Other decays receive all three kinds of contributions, and three kinds of contributions are important in most of decays.

   hep-phJ.Phys.G(2025)·1 citation
5. 05*

   Search for R-Parity-Violation-Induced Charged Lepton Flavor Violation at Future Lepton Colliders

   Xunye Cai🇨🇳 · Jingshu Li🇨🇳 · Ran Ding🇨🇳 · Meng Lu🇨🇳 · Zhengyun You🇨🇳 · Qiang Li🇨🇳

   Interest in searches for Charged Lepton Flavor Violation (CLFV) has continued in the past few decades since the observation of CLFV will indicate new physics beyond the Standard Model (BSM). As several future lepton colliders with high luminosity have been proposed, the search for CLFV will reach an unprecedented level of precision. Many BSM models allow CLFV processes at the tree level, such as the R-parity-violating (RPV) Minimal Supersymmetric Standard Model (MSSM), which is a good choice for benchmark. In this paper, we perform a detailed fast Monte Carlo simulation study on RPV-induced CLFV processes at future lepton colliders, including a 240 GeV circular electron positron collider (CEPC) and a 6 or 14 TeV muon collider. As a result, we found that the upper limits on the $\tau$ related RPV couplings will be significantly improved, while several new limits on RPV couplings can be set, which are inaccessible by low-energy experiments.

   hep-phUniverse(2024)·4 citations
6. 06*

   Heavy multiquark systems as clusters of smaller units -- a diffusion Monte Carlo calculation --

   M.C. Gordillo🇪🇸 · J. Segovia🇪🇸

   Multiquark systems appear less frequently than mesons and baryons despite the enormous world-wide experimental effort that has been made during the last two decades. In this work, we will propose a possible explanation for that fact, restricting ourselves to the case of sets including only $c$ and $\bar{c}$ quarks. We will show that those multiquarks can be thought as different combinations of smaller units that associate together to produce colorless assemblies with a definite value of the total spin. For instance, for the $cccccc$ hexaquark with $S=0$, we have three possibilities: a set of six undistinguishable $c$ quarks, an association of two $ccc$ baryons, or a set of three $cc$ diquarks close together. This means we can have three different values for the mass of an open-charm hexaquark with $S=0$. Using the diffusion Monte Carlo method, we calculate all possible combinations compatible with tetraquark $cc\bar{c}\bar{c}$, pentaquark $cccc\bar{c}$, open-charm $cccccc$ and hidden-charm $ccc\bar{c}\bar{c}\bar{c}$ hexaquark structures with the minimum value of total spin ($S=0$ or $S=1/2$). We consider compact structures with radial wave functions including interactions between all the quarks in the cluster. We find that, in all cases, the mass of the multiquark decreases with the number of small units that conform the set of quarks. For instance, an open charm hexaquark made up of three diquarks has a smaller mass than a set of six of $c$ undistinguishable units. When the pieces that conform the multiquark are themselves colorless with a definite value of the total spin, the cluster splits into those smaller units that separate infinitely from each other.

   hep-phhep-exhep-latnucl-ex+1PRD(2024)·8 citations
7. 07*

   Benchmark Lines and Planes for Higgs-to-Higgs Decays in the NMSSM

   Ulrich Ellwanger🇫🇷 · Margarete Muehlleitner🇩🇪 · Nikolaos Rompotis🇬🇧 · Nausheen R. Shah🇺🇸 · Daniel Winterbottom🇬🇧

   A number of benchmark scenarios for NMSSM Higgs boson searches via Higgs-to-Higgs decays at the LHC have been proposed by the NMSSM Subgroup of the LHC HWG3. Some of them are already in use by the ATLAS and CMS collaborations for the interpretation of their results from Run 2. In this document we summarize the theory setup, the underlying procedures and reproduce the benchmark scenarios in table form.

   hep-phhep-ex4 citations
8. 08*

   Probing gluon GTMDs of the proton in deep inelastic diffractive dijet production at HERA

   Barbara Linek🇵🇱 · Marta Łuszczak🇵🇱 · Wolfgang Schäfer🇵🇱 · Antoni Szczurek🇵🇱

   We calculate several differential distributions for diffractive dijets production in $ep\to e^{\prime }\mathrm{jet}\mathrm{jet}p$ in the pQCD dipole approach using off diagonal unintegrated gluon distributions (GTMDs). Different models from the literature are used. We concentrate on the contribution from exclusive $q\bar{q}$ dijets. Results of our calculations are compared to H1 and ZEUS data, including specific experimental cuts in our calculations. In general, except of one GTMD, our results are below the HERA data. The considered mechanism is expected to gives a sizeable contribution to the ZEUS data, while it is negligible in the kinematics of the H1 measurement. This is in contrast to recent results from the literature where the normalization was adjusted to some selected distributions of H1 collaboration and no agreement with other observables was checked. The ZEUS data provide stricter limitations on the GTMDs than the H1 data. We conclude, based on comparison to different observables, that the calculated cross sections are only a small fraction of the measured ones which contain probably also processes with pomeron remnant. Alternatively the experimental data could be explained by inclusion of $q\bar{q}g$ component. We present also azimuthal correlations between the sum and the difference of dijet transverse momenta. The cuts on transverse momenta of jets generate corresponding azimuthal correlations which can be misidentified as due to elliptic gluon distributions.

   hep-phPRD(2024)·6 citations
9. 09*

   Spectrum of $S$- and $P$-wave $cc\bar{q}{\bar{q}}^{\prime }$ $(\bar{q},{\bar{q}}^{\prime }=\bar{u},\bar{d},\bar{s})$ systems in a chiral SU(3) quark model

   Du Wang🇨🇳 · Ke-Rang Song🇨🇳 · Wen-Ling Wang🇨🇳 · Fei Huang🇨🇳

   Inspired by the resonance $T_{cc}^{+}(3875)$ recently observed by the LHCb Collaboration, we systematically explore the $S$- and $P$-wave $cc\bar{q}{\bar{q}}^{\prime }$ $(\bar{q},{\bar{q}}^{\prime }=\bar{u},\bar{d},\bar{s})$ systems in a chiral SU(3) quark model. The Hamiltonian contains the kinetic energy, the one-gluon-exchange (OGE) potential, the confinement potential, and the one-boson-exchange (OBE) potential stemming from the coupling of quark and chiral fields. The Schrödinger equation is solved by use of the variational method with the spacial trial wave functions chosen as Gaussian functions. It is found that the lowest state has a mass $3879$ MeV, isospin and spin-parity $I{J}^P=01^{+}$, and quark constituent $cc\bar{u}\bar{d}$, in agreement with the experimentally observed $T_{cc}^{+}(3875)$. This state is approximately at the calculated $D{D}^{\ast }$ threshold, and has a root-mean-square radius about $0.48$ fm. These demonstrates that the $T_{cc}^{+}(3875)$ can be accommodated as a stable and compact tetraquark sate in the chiral SU(3) quark model. All the other $S$- and $P$-wave $cc\bar{q}{\bar{q}}^{\prime }$ $(\bar{q},{\bar{q}}^{\prime }=\bar{u},\bar{d},\bar{s})$ states lie about one hundred to few hundreds MeV higher than the corresponding meson-meson thresholds, and thus are not suggested to be candidates of stable and compact tetraquark states due to their fall-apart decays to two mesons.

   hep-phnucl-thPRD(2024)·11 citations
10. 10*

    The NNLO gluon beam function for jet-veto resummation

    Guido Bell🇩🇪 · Kevin Brune🇩🇪 · Goutam Das🇩🇪 · Ding Yu Shao🇨🇳 · Marcel Wald🇩🇪

    We compute the gluon beam function for jet-veto resummation to next-to-next-to-leading order (NNLO) in the strong-coupling expansion. Our calculation is based on an automated framework that was previously used for the computation of the respective quark beam function, and which we significantly extended for the present calculation. In particular, the perturbative matching kernels are directly calculated in momentum space, without the need to perform an additional Mellin transform. We present results for both gluon and quark-initiated processes, which we cross-checked with an independent semi-analytical method that exploits the similarity of the beam functions to the more familiar case of transverse-momentum resummation. Our computation is relevant for jet-veto resummations at NNLL${}^{\prime }$ accuracy.

    hep-phJHEP(2024)·5 citations
11. 11*

    Gravitational Wave Sourced by Decay of Massive Particle from Primordial Black Hole evaporation

    Ki-Young Choi🇰🇷 · Erdenebulgan Lkhagvadorj🇰🇷 · Satyabrata Mahapatra🇰🇷

    In this article, we investigate the stochastic gravitational waves (GWs) spectrum, resulting from the emission of gravitons through bremsstrahlung, in the decay of particles produced by Hawking radiation. Although particle decays inevitably entail the emission of graviton due to bremsstrahlung, the associated decay width is notably suppressed due to the Planck scale suppression in the coupling of matter fields to gravitons. Consequently, the relic abundance of such GWs constituted of these gravitons undergoes a corresponding reduction. However, we demonstrate that super-heavy particles, reaching masses as high as Planck scale, can emerge naturally in the Hawking radiation of evaporating primordial black holes (PBHs) and can compensate for this suppression. In addition, we also discuss the stochastic gravitational waves constituted out of the gravitons directly radiated from such evaporating PBHs. When the super-heavy particle decays promptly after its production, then the corresponding GW spectrum remains subdominant to the one arising from direct PBH evaporation. However, if this particle is long-lived and decays after PBH evaporation, then the resulting GWs produced in these two processes have two distinct spectra with their peaks at extremely high frequencies, providing avenues for proposed ultra-high frequency gravitational wave detectors. We also show that such gravitational waves contribute significantly to substantial dark radiation, which can be probed with the enhanced sensitivity of future experiments.

    hep-phJCAP(2024)·21 citations
12. 12*

    An alternative approach to baryon masses in the $1/N_c$ expansion of QCD

    Ruben Flores-Mendieta🇲🇽 · Sergio Alejandro Garcia-Monreal🇲🇽 · Luis Roman Ruiz-Robles🇲🇽 · Francisco Alberto Torres-Bautista🇲🇽

    The baryon mass operator is studied within a combined expansion in $1/N_c$ and perturbative $SU(3)$ flavor symmetry breaking, where $N_c$ denotes the number of quark charges. Flavor projection operators are used to classify the baryon operators involved in the expansion, which fall into the flavor representations $1$, $8$, $10+\overline{10}$, $27$, $35+\overline{35}$ and $64$. This approach allows one to incorporate up to third-order flavor symmetry breaking in the baryon mass operator in a rigorous and systematic way. Previous work on the subject is considered to validate the approach. A fit to data is performed to evaluate the free parameters in the theory and to produce some numerical values of baryon masses. Results are consistent and reaffirm the striking success of the $1/N_c$ expansion.

    hep-phPRD(2024)·4 citations
13. 13*

    Energy-dependent Boosted Dark Matter from Diffuse Supernova Neutrino Background

    Anirban Das🇰🇷 · Tim Herbermann🇩🇪 · Manibrata Sen🇩🇪 · Volodymyr Takhistov🇯🇵

    Diffuse neutrinos from past supernovae in the Universe present us with a unique opportunity to test dark matter (DM) interactions. These neutrinos can scatter and boost the DM particles in the Milky Way halo to relativistic energies allowing us to detect them in terrestrial laboratories. Focusing on generic models of DM-neutrino and electron interactions, mediated by a vector or a scalar boson, we implement energy-dependent scattering cross-sections and perform detailed numerical analysis of DM attenuation due to electron scattering in-medium while propagating towards terrestrial experiments. We set new limits on DM-neutrino and electron interactions for DM with masses in the range $\sim (0.1,10^4)$MeV, using recent data from XENONnT, LUX-ZEPLIN, and PandaX-4T direct detection experiments. We demonstrate that consideration of energy-dependent cross-sections for DM interactions can significantly affect constraints previously derived under the assumption of constant cross-sections, modifying them by multiple orders of magnitude.

    hep-phastro-ph.COhep-exJCAP(2024)·30 citations
14. 14*

    Production of dark sector particles via resonant positron annihilation on atomic electrons

    Fernando Arias-Aragón🇮🇹 · Luc Darmé🇫🇷 · Giovanni Grilli di Cortona🇮🇹 · Enrico Nardi🇮🇹

    Resonant positron annihilation on atomic electrons provides a powerful method to search for light new particles coupled to $e^{+}{e}^{-}$. Reliable estimates of production rates require a detailed characterization of electron momentum distributions. We describe a general method that harnesses the target material Compton profile to properly include electron velocity effects in resonant annihilation cross-sections. We additionally find that high $Z$ atoms can efficiently act as particle physics accelerators, providing a density of relativistic electrons that allows to extend by several times the experimental mass reach.

    hep-phhep-exPRL(2024)·29 citations
15. 15*

    Generation of narrow beams of super high-energy gamma quanta in the resonant inverse Compton-effect in the field of a strong x-ray wave

    Sergei P. Roshchupkin🇷🇺 · Sergey B. Makarov🇷🇺

    The article presents a theoretical study of Oleinik resonances in the process of scattering a gamma quantum by an ultrarelativistic electron in the field of a strong electromagnetic wave. It is shown that under resonant conditions, the scattering channels of the reaction effectively split into two first-order processes according to a fine structure constant such as the external field-stimulated Compton effect. And the annihilation channel of the reaction effectively decays into direct and reverse the external field-stimulated Breit-Wheeler processes. The significant dependence of the resonant energy of final particles and resonant cross sections on the outgoing angles of the final gamma quantum, the number of absorbed and emitted photons of the wave, as well as the characteristic quantum parameters of the problem is shown. These quantum parameters are determined by the ratio of the initial particle energies to the characteristic energies of the Compton effect and the Breit-Wheeler process. An unambiguous relationship between the outgoing angles of final electrons and gamma quanta has been obtained, which qualitatively distinguishes the resonant process from the non-resonant one. The cases when the energy of the initial electrons significantly exceeds the energy of the initial gamma quanta have been studied. The conditions under which the energy of high-energy initial electrons is converted into the energy of final gamma quanta are obtained. At the same time, the resonant differential cross-section of such a process significantly (by several orders of magnitude) exceeds the corresponding non-resonant cross-section. This theoretical study predicts a number of new physical effects that may explain the high-energy fluxes of gamma quanta born near neutron stars and magnetars.

    hep-phastro-ph.HEhep-thPhoton.(2024)·5 citations
16. 16*

    Probing sterile neutrino freeze-in at stronger coupling

    Niko Koivunen🇪🇪 · Oleg Lebedev🇫🇮 · Martti Raidal🇪🇪

    The regime of dark matter (DM) freeze-in at stronger coupling interpolates between freeze-in and freeze-out. It relies on Boltzmann-suppressed dark matter production, implying that the Standard Model bath temperature never exceeds the dark matter mass. In this work, we study this regime in the context of sterile neutrino dark matter, which can be sufficiently long-lived for a tiny sterile-active mixing. The sterile neutrino is assumed to couple to a real singlet scalar, providing for a thermal production mechanism of the former. We find that DM mass can range from GeV to tens of TeV consistently with all the constraints. The most interesting aspect of the consequent freeze-in phenomenology is that the sterile neutrino dark matter can be probed efficiently by both direct detection experiments and invisible Higgs decay at the LHC.

    hep-phhep-exEPJC(2024)·21 citations
17. 17*

    Momentum shift and on-shell constructible massive amplitudes

    Yohei Ema🇺🇸 · Ting Gao🇺🇸 · Wenqi Ke🇺🇸 · Zhen Liu🇺🇸 · Kun-Feng Lyu🇺🇸 · Ishmam Mahbub🇺🇸

    We construct tree-level amplitude for massive particles using on-shell recursion relations based on two classes of momentum shifts: an all-line transverse shift that deforms momentum by its transverse polarization vector, and a massive BCFW-type shift. We illustrate that these shifts allow us to correctly calculate four-point and five-point amplitudes in massive QED, without an ambiguity associated with the contact terms that may arise from a simple ''gluing'' of lower-point on-shell amplitudes. We discuss various aspects and applicability of the two shifts, including the large-z behavior and complexity scaling. We show that there exists a ''good'' all-line transverse shift for all possible little group configurations of the external particles, which can be extended to a broader class of theories with massive particles such as massive QCD and theories with massive spin-1 particles. The massive BCFW-type shift enjoys more simplicity, but a ''good'' shift does not exist for all the spin states due to the specific choice of spin axis.

    hep-phhep-thPRD(2024)·20 citations
18. 18*

    From pole parameters to line shapes and branching ratios

    L. A. Heuser🇩🇪 · G. Chanturia🇩🇪 · F.-K. Guo🇨🇳 · C. Hanhart🇩🇪 · M. Hoferichter🇨🇭 · B. Kubis🇩🇪

    Resonances are uniquely characterized by their complex pole locations and the corresponding residues. In practice, however, resonances are typically identified experimentally as structures in invariant mass distributions, with branching fractions of resonances determined as ratios of count rates. To make contact between these quantities it is necessary to connect line shapes and resonance parameters. In this work we propose such a connection and illustrate the formalism with detailed studies of the $\rho (770)$ and $f_0(500)$ resonances. Based on the line shapes inferred from the resonance parameters along these lines, expressions for partial widths and branching ratios are derived and compared to other approaches in the literature.

    hep-phhep-exnucl-thEPJC(2024)·31 citations
19. 19*

    Minimal decaying dark matter: from cosmological tensions to neutrino signatures

    Lea Fuß🇩🇪 · Mathias Garny🇩🇪 · Alejandro Ibarra🇩🇪

    The invisible decay of cold dark matter into a slightly lighter dark sector particle on cosmological time-scales has been proposed as a solution to the $S_8$ tension. In this work we discuss the possible embedding of this scenario within a particle physics framework, and we investigate its phenomenology. We identify a minimal dark matter decay setup that addresses the $S_8$ tension, while avoiding the stringent constraints from indirect dark matter searches. In our scenario, the dark sector contains two singlet fermions $N_{1,2}$, quasi-degenerate in mass, and carrying lepton number so that the heaviest state ($N_2$) decays into the lightest ($N_1$) and two neutrinos via a higher-dimensional operator $N_2\to {\bar{N}}_1\nu \nu$. The conservation of lepton number, and the small phase-space available for the decay, forbids the decay channels into hadrons and strongly suppresses the decays into photons or charged leptons. We derive complementary constraints on the model parameters from neutrino detectors, freeze-in dark matter production via $\nu \nu \to N_1{N}_2$, collider experiments and blazar observations, and we show that the upcoming JUNO neutrino observatory could detect signals of dark matter decay for model parameters addressing the $S_8$ tension if the dark matter mass is below $\simeq 1$ GeV.

    hep-phastro-ph.COJCAP(2025)·15 citations
20. 20*

    Bottomonium suppression from the three-loop QCD potential

    Nora Brambilla🇩🇪 · Tom Magorsch🇩🇪 · Michael Strickland🇺🇸 · Antonio Vairo🇩🇪 · Peter Vander Griend🇺🇸

    We compute the suppression of bottomonium in the quark-gluon plasma using the three-loop QCD static potential. The potential describes the spin-averaged bottomonium spectrum below threshold with a less than 1% error. Within potential nonrelativistic quantum chromodynamics and an open quantum systems framework, we compute the evolution of the bottomonium density matrix. The values of the quarkonium transport coefficients are obtained from lattice QCD measurements of the bottomonium in-medium width and thermal mass shift; we additionally include for the first time a vacuum contribution to the dispersive coefficient $\gamma$. Using the three-loop potential and the values of the heavy quarkonium transport coefficients, we find that the resulting bottomonium nuclear modification factor is consistent with experimental observations, while at the same time reproducing the lattice measurements of the in-medium width.

    hep-phhep-exnucl-exnucl-thPRD(2024)·21 citations
21. 21*

    First investigation of void statistics in numerical relativity simulations

    Michael J. Williams🇳🇿 · Hayley J. Macpherson🇺🇸 · David L. Wiltshire🇳🇿 · Chris Stevens🇳🇿

    We apply and extend standard tools for void statistics to cosmological simulations that solve Einstein's equations with numerical relativity (NR). We obtain a simulated void catalogue without Newtonian approximations, using a new watershed void finder which operates on fluid-based NR simulations produced with the Einstein Toolkit. We compare and contrast measures of void size and void fraction, and compare radial stacked density profiles to empirically-derived Hamaus-Sutter-Wandelt (HSW) density profiles and profiles based on distance to void boundaries. We recover statistics roughly consistent with Newtonian N-body simulations where such a comparison is meaningful. We study variation of dynamical spatial curvature and local expansion explicitly demonstrating the spatial fluctuations of these quantities in void regions. We find that voids in our simulations expand ~10-30% faster than the global average and the spatial curvature density parameter in the centre of voids reaches ~60-80%.

    ↳ astro-ph.COgr-qchep-phMNRAS(2025)·18 citations
22. 22*

    Structure Formation in Various Dynamical Dark Energy Scenarios

    Masoume Reyhani · Mahdi Najafi · Javad T. Firouzjaee🇮🇷 · Eleonora Di Valentino🇬🇧

    This research investigates the impact of the nature of Dark Energy (DE) on structure formation, focusing on the matter power spectrum and the Integrated Sachs-Wolfe effect (ISW). By analyzing the matter power spectrum at redshifts $z=0$ and $z=5$, as well as the ISW effect on the scale of $\ell =10-100$, the study provides valuable insights into the influence of DE equations of state (EoS) on structure formation. The findings reveal that dynamical DE models exhibit a stronger matter power spectrum compared to constant DE models, with the JBP model demonstrating the highest amplitude and the CPL model the weakest. Additionally, the study delves into the ISW effect, highlighting the time evolution of the ISW source term $\mathcal{F}(a)$ and its derivative $d\mathcal{F}(a)/da$, and demonstrating that models with constant DE EoS exhibit a stronger amplitude of $\mathcal{F}(a)$ overall, while dynamical models such as CPL exhibit the highest amplitude among the dynamical models, whereas JBP has the lowest. The study also explores the ISW auto-correlation power spectrum and the ISW cross-correlation power spectrum, revealing that dynamical DE models dominate over those with constant DE EoS across various surveys. Moreover, it emphasizes the potential of studying the non-linear matter power spectrum and incorporating datasets from the small scales to further elucidate the dynamical nature of dark energy. This comprehensive analysis underscores the significance of both the matter power spectrum and the ISW signal in discerning the nature of dark energy, paving the way for future research to explore the matter power spectrum at higher redshifts and in the non-linear regime, providing deeper insights into the dynamical nature of dark energy.

    ↳ astro-ph.COgr-qchep-phPhys.Dark Univ.(2024)·17 citations
23. 23*

    X-ray emission spectrum for axion-photon conversion in magnetospheres of strongly magnetized neutron stars

    Shubham Yadav🇮🇳 · M. Mishra🇮🇳 · Tapomoy Guha Sarkar🇮🇳

    Detecting axionic dark matter (DM) could be possible in an X-ray spectrum from strongly magnetized neutron stars (NSs). We examine the possibility of axion-photon conversion in the magnetospheres of strongly magnetized NSs. In the current work, we investigate how the modified Tolman Oppenheimer Volkoff (TOV) system of equations (in the presence of a magnetic field) affects the energy spectrum of axions and axions-converted-photon flux. We have considered the distance-dependent magnetic field in the modified TOV system of equations. We employ three different equations of states (EoSs), namely APR, FPS, and SLY, to solve these equations. We obtain the axions emission rate by including the Cooper-pair-breaking formation process and Bremsstrahlung process in the core of NSs using the NSCool code. We primarily focus on Magnificient seven (M7) star RXJ 1856.5-3754. We further investigate the impact of the magnetic field on the actual observables, such as axion energy spectrum and axion-converted-photon flux at an axion mass in meV range by assuming mass $M_{NS}\sim 1.4M_{\odot }$. We compare our calculated axion-converted-photon flux from all available archival data sets from PN+MOS+Chandra. We also study the variation of the energy spectrum at a fixed energy with varying central magnetic fields. Our predicted axion-converted-photon flux values as a function of axion energy closely follow the experimentally archival data, which allows us to put bounds on the axion mass for the three EoS.

    ↳ astro-ph.HEhep-phEPJC(2024)·9 citations
24. 24*

    Might Normal Nuclear Matter be Quarkyonic?

    Volker Koch🇺🇸 · Larry McLerran🇺🇸 · Gerald A. Miller🇺🇸 · Volodymyr Vovchenko🇺🇸

    The possibility that nuclear matter might be Quarkyonic is considered. Quarkyonic matter is high baryon density matter that is confined but can be approximately thought of as a filled Fermi sea of quarks surrounded by a shell of nucleons. Here, nuclear matter is described by the IdylliQ sigma model for Quarkyonic matter, generalizing the non-interacting IdylliQ model [Y. Fujimoto et al., Phys. Rev. Lett. 132, 112701 (2024) [arXiv:2306.04304]] to include interactions with a sigma meson and a pion. When such interactions are included, we find that isospin-symmetric nuclear matter binds, with acceptable values of the compressibility and other parameters for nuclear matter at saturation. The energy per nucleon and sound velocity of such matter is computed, and the isospin dependence is determined. Nuclear matter is formed at a density close to but slightly above the density at which Quarkyonic matter forms. Quarkyonic matter predicts a strong depletion of nucleons in normal nuclear matter at low momentum. Such a depletion for nucleon momenta $k\lesssim 120$ MeV is shown to be consistent with electron scattering data.

    ↳ nucl-thhep-phPRC(2024)·26 citations
25. 25*

    Scalar field with a time-independent classical source, not trivial after all: from vacuum decay to scattering

    Leonardo Tinti🇵🇱 · Arthur Vereijken🇵🇱 · Shahriyar Jafarzade🇵🇱 · Francesco Giacosa🇵🇱

    Historically it has been believed that a time-independent classical source has no effect on the scattering of relativistic uncharged field, in contrast with single particle quantum mechanics. In this work we show that the dynamics is not trivial. We solve exactly for the scattering amplitudes and find that a key ingredient is the production of particles from the unstable vacuum, conceptually similar to the Schwinger mechanism. We compute exactly the probabilities for the vacuum to decay in $n$ particles. The time dependence of such probabilities displays interesting properties such as the quantum Zeno effect and in particular has no regime where the exponential decay law is a good approximation. We show that the trivial scattering found in the past is the byproduct of the adiabatic switching of the interaction. In fact, it is not possible to switch off the interaction (adiabatically or otherwise) at distant times and recover the exact results. Finally, this non trivial vacuum behavior is a source of particle production. We argue that such non-perturbative calculations can be phenomenologically relevant for the production processes that are suppressed at the lower orders in perturbation theory, for instance dilaton production in a medium.

    ↳ hep-thhep-phnucl-thquant-phPRD(2024)·1 citation
26. 26*

    Symmetry breaking due to multi-angle matter-neutrino resonance in neutron star merger remnants

    Ian Padilla-Gay🇺🇸 · Shashank Shalgar🇩🇰 · Irene Tamborra🇩🇰

    Neutron star merger remnants are unique sites for exploring neutrino flavor conversion in dense media. Because of the natural excess of ${\bar{\nu }}_e$ over ${\nu }_e$, the neutrino-neutrino potential can cancel the matter potential, giving rise to matter-neutrino resonant flavor conversion. Under the assumption of two (anti)neutrino flavors and spatial homogeneity, we solve the neutrino quantum kinetic equations to investigate the occurrence of the matter-neutrino resonance within a multi-angle framework. We find that isotropy is broken spontaneously, regardless of the mass ordering. Relying on a hydrodynamical simulation of a binary neutron star merger remnant with a black hole of $3M_{\odot }$ and an accretion torus of $0.3M_{\odot }$, we find that complete flavor conversion caused by the matter-neutrino resonance is unlikely, although the matter and neutrino potentials cancel at various locations above the disk. Importantly, the matter-neutrino resonant flavor conversion crucially depends on the shape of the neutrino angular distributions. Our findings suggest that an accurate modeling of the neutrino angular distributions is necessary to understand flavor conversion physics in merger remnants, its implications on the disk physics and synthesis of the elements heavier than iron.

    ↳ astro-ph.HEhep-phJCAP(2024)·10 citations
27. 27*

    Runaway Gravitational Production of Dark Photons

    Christian Capanelli🇨🇦 · Leah Jenks🇺🇸 · Edward W. Kolb🇺🇸 · Evan McDonough🇨🇦

    We demonstrate that gravitational particle production (GPP) of a massive, Abelian, vector (Proca) field during inflation in the presence of nonminimal coupling to gravity may suffer from an instability which leads to runaway production of high-momentum modes. This is untenable unless there is some mechanism to regulate the runaway. We discuss the parameter space of the particle mass and nonminimal couplings where such a runaway occurs and possible ways to tame the runaway. We find that there is no obvious way to resolve the runaway in a UV completion or with kinetic mixing to the standard model.

    ↳ hep-thastro-ph.COgr-qchep-phPRL(2024)·34 citations
28. 28*

    Significant impact of Galactic dark matter particles on annihilation signals from Sagittarius analogues

    Evan Vienneau🇨🇦 · Addy J. Evans🇺🇸 · Odelia V. Hartl🇨🇦 · Nassim Bozorgnia🇨🇦 · Louis E. Strigari🇺🇸 · Alexander H. Riley🇬🇧 · Nora Shipp🇺🇸

    We examine the gamma-ray signal from dark matter (DM) annihilation from analogues of the Sagittarius (Sgr) dwarf spheroidal galaxy in the Auriga cosmological simulations. For velocity-dependent annihilation cross sections, we compute emissions from simulated Sgr subhalos and from the Milky Way (MW) foreground. In addition to the annihilation signals from DM particles bound to Sgr, we consider for the first time the annihilation of DM particles bound to the MW that overlap spatially with Sgr. For p-wave models this contribution can enhance the signal by over an order of magnitude, while for d-wave models the enhancement can be over three orders of magnitude. For Sommerfeld and s-wave models, the corresponding emission does not significantly change. For the Sommerfeld model, the Sgr source can be visible above the MW foreground emission, while for s, p and d-wave models, the signal towards Sgr is most likely dominated by foreground MW emission. We interpret our results within the context of the observed gamma-ray emission from Sgr. We find that, given the background emission estimated from this region, the templates from simulations likely have spatial morphology that is too extended to explain the point-like emission that is observed.

    ↳ astro-ph.HEastro-ph.COhep-phJCAP(2024)·5 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.