Fri·May 31, 2024Friday·May 31, 2024

1. 01*

   Supernova electron-neutrino interactions with xenon in the nEXO detector

   nEXO Collaboration: S. Hedges🇺🇸 · S. Al Kharusi🇺🇸 · E. Angelico🇺🇸 · J. P. Brodsky🇺🇸 · G. Richardson🇺🇸 · S. Wilde🇺🇸 · A. Amy🇫🇷 · A. Anker🇺🇸 · I. J. Arnquist🇺🇸 · P. Arsenault🇨🇦 · A. Atencio🇺🇸 · I. Badhrees🇨🇦 and 134 other authors

   Electron-neutrino charged-current interactions with xenon nuclei were modeled in the nEXO neutrinoless double-$\beta$ decay detector (~5 metric ton, 90% ${}^{136}$Xe, 10% ${}^{134}$Xe) to evaluate its sensitivity to supernova neutrinos. Predictions for event rates and detectable signatures were modeled using the Model of Argon Reaction Low Energy Yields (MARLEY) event generator. We find good agreement between MARLEY's predictions and existing theoretical calculations of the inclusive cross sections at supernova neutrino energies. The interactions modeled by MARLEY were simulated within the nEXO simulation framework and were run through an example reconstruction algorithm to determine the detector's efficiency for reconstructing these events. The simulated data, incorporating the detector response, were used to study the ability of nEXO to reconstruct the incident electron-neutrino spectrum and these results were extended to a larger xenon detector of the same isotope enrichment. We estimate that nEXO will be able to observe electron-neutrino interactions with xenon from supernovae as far as 5-8 kpc from Earth, while the ability to reconstruct incident electron-neutrino spectrum parameters from observed interactions in nEXO is limited to closer supernovae.

   hep-phhep-exnucl-thPRD(2024)·4 citations
2. 02*

   Darker matter generating from the dark

   Wan-Zhe Feng🇨🇳 · Zi-Hui Zhang🇨🇳

   The non-detection of dark matter may be attributed to the dark matter residing in a darker hidden sector. We explore the possibility that a hidden sector produced through the freeze-in mechanism, can further generate an even more hidden sector via an additional freeze-in process. Such a two-step freeze-in process produces dark matter coupled weaker-than-ultraweakly to the standard model particles, and is thus referred to as the "darker matter". To illustrate the two-step freeze-in process, we study a model featuring two $U(1)$ hidden sectors. The first $U(1)$ sector is directly coupled to the standard model with feeble interactions, while the second $U(1)$ sector is directly coupled to the first $U(1)$ sector and thus only indirectly to the standard model, rendering it darker. Remarkably, darker matter candidates residing in the second darker $U(1)$ sector, generated from the two-step freeze-in process, can account for almost the entire observed dark matter relic density. The darker matter, interacted with standard model particles through ultraweak couplings, can exhibit velocity-dependent self-interacting cross-sections, which potentially provides an explanation for addressing problems associated with cosmic small-scale structures. Additionally, the dark photon darker matter residing in the darker hidden sector can be responsible for the galactic 511 keV photon signal, consistent with various dark matter density profiles.

   hep-phPRD(2025)·8 citations
3. 03*

   NLO friction in symmetry restoring phase transitions

   Aleksandr Azatov🇮🇹 · Giulio Barni🇮🇹 · Rudin Petrossian-Byrne🇮🇹

   Interactions between bubbles/domain walls and the surrounding medium are a topic of active research, particularly as they apply to friction effects on accelerated expansion during first-order phase transitions. In this paper, we analyze for the first time friction pressure on relativistic walls in phase transitions where gauge symmetry is restored, particularly motivated by the observation that this pressure can, in principle, be negative at leading order, since some particles lose mass by definition as they cross into the new phase. We find, however, that at NLO, the soft emission of vectors from a charged current leads to positive pressure scaling as the wall's Lorentz boost factor ${\gamma }_w$, similar to the case of gauge symmetry breaking. Contrary to the latter case, we find that the dominant contribution in single emission is safe from IR divergences and exhibits a much stronger dependence on the wall shape. Finally, we argue that in any phase transition, no multi-particle process on the wall can impart negative pressure greater than the leading order result, in the asymptotic limit of large velocity.

   hep-phastro-ph.COhep-thJHEP(2024)·19 citations
4. 04*

   Causal fermion states in magnetic field in a relativistic rotating frame and electromagnetic radiation by a rapidly rotating charge

   Matteo Buzzegoli🇺🇸 · Kirill Tuchin🇺🇸

   We consider the Dirac field uniformly rotating with angular velocity $\Omega$ and also subject to the constant magnetic field $B$ directed along the rotation axis. The causal states are constrained to the interior of the light cylinder of radius $c/\Omega$. When this radius is smaller than the system size, as in the quark-gluon plasma, the effect of the boundary on the fermion spectrum is critical. We derive the fermion spectrum and study its properties. We compute the intensity of the electromagnetic radiation emitted due to transitions between the fermion states. We study its dependence on energy and angular momentum for different values of the angular velocity and the magnetic field. Rotation has enormous impact on the electromagnetic radiation by the quark-gluon plasma with or without the magnetic field.

   hep-phastro-ph.HEnucl-thPRD(2024)·5 citations
5. 05*

   Photon emission by an electron in a constant background field modeling a Lorentz-noninvariant vacuum

   Anatoly V. Borisov🇷🇺

   The power and the probability of electromagnetic radiation from an electron in a constant background tensor field violating Lorentz invariance are calculated. The case of a background field of the quasielectric type is considered. The angular distribution and the polarization of the radiation are studied. Using present experimental constraints on the background field strength, it is shown that the radiation effect can manifest itself under astrophysical conditions at ultrahigh electron energy.

   hep-phPTEP(2024)·1 citation
6. 06*

   Primitive Pythagorean triples and neutrino mixing

   Yuta Hyodo🇯🇵 · Teruyuki Kitabayashi🇯🇵

   The primitive Pythagorean triples are the three natural numbers $(a,b,c)$ that satisfy $c^2=a^2+b^2$ in a right triangle. We constructed a neutrino mixing models related to primitive Pythagorean triples that satisfy the observed values within the $3\sigma$ region for the reactor, solar, and atmospheric neutrino mixing angles, as well as the Dirac CP phase.

   hep-ph0 citations
7. 07*

   Single spin asymmetry $A_{UL}^{\sin (2{\varphi }_h)}$ in dihadron production in SIDIS

   Ren Yang🇨🇳 · Yangyang Yu🇨🇳 · Qihang Zhou🇨🇳 · Gang Li🇨🇳 · Mao Song🇨🇳 · Xuan Luo🇨🇳

   The paper calculates the helicity-dependent dihadron fragmentation function (DiFF), by extending the dihadron spectator model and examine the single longitudinal spin asymmetry $A_{UL}^{\sin (2{\varphi }_h)}$ from dihadron in semi-inclusive inelastic scattering (SIDIS). This function elucidates the relationship between the longitudinal polarization of the fragmented quark and the transverse momentum of the resulting hadron pairs. A study by the COMPASS collaboration detected a minimal signal in their experimental search for this azimuthal asymmetry in SIDIS. Here, we use the spectator model to calculate the unknown T-odd dihadron fragmentation function $H_1^{\perp }$. Adopting collinear factorization to describe the data, avoiding the transverse momentum dependent factorization and the associated resummation effects, helping us understand the asymmetry and explaining why the signal is so weak. We involve the approach of transverse momentum dependence in the model calculations, in order to formulate the differential cross sections and the spin asymmetries in terms of the collinear parton distributions and the collinear DiFFs. A transverse momentum factor analysis method was used, in which the transverse momentum of the final hadron pairs was not integrated. The asymmetry of $sin(2{\varphi }_h)$ in COMPASS kinematics was calculated and compared with experimental data. In addition, predictions for the same asymmetry are also presented for HERMES and the Electron Ion Collider.

   hep-phPRD(2024)·0 citations
8. 08*

   Status of QCD precision predictions for Drell-Yan rapidity distributions

   S. Alekhin🇩🇪 · S. Amoroso🇩🇪 · L. Buonocore🇨🇭 · A. Huss🇨🇭 · S. Kallweit🇨🇭 · A. Kardos🇭🇺 · J. Michel🇳🇱 · S. Moch🇩🇪 · F. Petriello🇺🇸 · L. Rottoli🇨🇭 · Z. Trócsányi🇭🇺 · M. Wiesemann🇩🇪

   We compute differential distributions for Drell-Yan processes at the LHC and the Tevatron colliders at next-to-next-to-leading order in perturbative QCD, including fiducial cuts on the decay leptons in the final state. The comparison of predictions obtained with four different codes shows excellent agreement, once linear power corrections from the fiducial cuts are included in those codes that rely on phase-space slicing subtraction schemes. For Z-boson production we perform a detailed study of the symmetric cuts on the transverse momenta of the decay leptons. Predictions at fixed order in perturbative QCD for those symmetric cuts, typically imposed in experiments, suffer from an instability. We show how this can be remedied by an all-order resummation of the fiducial transverse momentum spectrum, and we comment on the choice of cuts for future experimental analyses.

   hep-phEPJC(2025)·6 citations
9. 09*

   CPT, Majorana fermions, and particle physics beyond the Standard Model

   Ken-ichi Hikasa🇯🇵

   After reviewing charge conjugation and the CPT theorem, we define Majorana fermions and clarify the relationship of Majorana, Weyl, and Dirac fields. Appearance of Majorana fermions in various scenarios of physics beyond the Standard Model is discussed, including neutrino masses, baryon asymmetry of the universe, grand unified theories, and supersymmetry.

   hep-phhep-thPTEP(2024)·1 citation
10. 10*

    Discontinuities of banana integrals in dispersion relation representation

    Xu-Liang Chen🇨🇳 · Peng-Fei Yang🇨🇳 · Wei Chen🇨🇳

    We derive the discontinuities of banana integrals using the dispersion relation iteratively. We find a series of identities between the parameterized discontinuities of banana integrals (p-DOBIs). Similar to elliptic integrals, these identities enable the reduction of various p-DOBIs to be a linear combination of some fundamental ones. We present a practical application of p-DOBIs for deriving Picard-Fuchs operator. Then we establish the expression of generalized dispersion relation, which enables us to obtain the dispersion relation representation of arbitrary banana integrals. Moreover, we propose a hypothesis for generalized dispersion relation and p-DOBIs, which provides a simple way to calculate the discontinuities and transform dispersion relation representation to p-DOBIs.

    hep-phhep-thChin.Phys.Lett.(2024)·5 citations
11. 11*

    Tau Physics Opportunities at the Super Tau-Charm Facility

    Antonio Pich🇪🇸

    The super tau-charm facility will provide excellent conditions to perform a high-precision investigation of the tau-lepton properties: very high statistics, controllable systematics and low backgrounds. An overview of the broad physics program that could be addressed at this facility is presented.

    hep-phhep-exInt.J.Mod.Phys.A(2024)·7 citations
12. 12*

    Color dipole cross-section from unifying the color dipole picture and improved saturation models

    G.R.Boroun🇮🇷

    We present an analysis of the color-dipole picture (CDP) for determination of the gluon density at low-$x$ which is obtained from the Altarelli-Martinelli equation by expansion at distinct points of expansion. The dipole cross-sections with respect to the improved saturation model of Bartels-Golec-Biernat-Kowalski (BGK) are obtained in a wide range of transverse sizes $r$ and compared with the Golec-Biernat-W$\ddot{\mathrm{u}}$sthoff (GBW) model. We find that the model gives a good description of the dipole cross-section at large $r$ which confirms saturation and matches the perturbative QCD result at a small $r$ due to the significant role of the running of the gluon distribution. The transition between these regions occurs with decreasing transverse sizes with a decrease of Bjorken $x$ and dependence on the expansion point.

    hep-phCommun.Theor.Phys.(2025)·1 citation
13. 13*

    Prospect of measuring the top quark mass through energy correlators

    Meng Xiao🇨🇳 · Yulei Ye🇨🇳 · Xinyu Zhu🇨🇳

    Reaching a high precision of the top quark mass is an important task of the Large Hadron Collider. We perform a feasibility study of measuring the top quark mass through the three-point energy correlator. The expected sensitivity of the top quark mass in the boosted regime is presented. We further introduce its application to the low top $p_{\text{T}}$ regime and demonstrate that both the W boson and the top quark masses could be extracted from this single observable. Compared to traditional observables, the energy correlator shows robustness to uncertainties that usually dominate experimental measurements and provides a promising way to improve experimental precision.

    hep-phJHEP(2024)·22 citations
14. 14*

    Lepton flavor violation with tau leptons

    Julian Heeck🇺🇸

    We review the status and importance of lepton flavor violation with tauons, focusing on overlooked flavor-breaking patterns as well as tau-flavor violation in nucleon decays.

    hep-phhep-exSciPost Phys.Proc.(2025)·0 citations
15. 15*

    Detailed nuclear structure calculations for coherent elastic neutrino-nucleus scattering

    Raghda Abdel Khaleq🇦🇺 · Jayden L. Newstead🇦🇺 · Cedric Simenel🇦🇺 · Andrew E. Stuchbery🇦🇺

    Any discovery of `new physics' in the neutrino sector first requires a precise prediction of the expected Standard Model cross section. Currently, Coherent Elastic neutrino-Nucleus Scattering (CEvNS) experiments are statistics limited. However, as new and future experiments scale up, it will be necessary to improve the theoretical predictions. Here we review the calculation of the CEvNS cross section in a consistent theory of hadronic currents and compute the relevant nuclear form factors using the nuclear shell model. The uncertainty on the form factors is explored by repeating the calculation for various shell model interactions and with Skyme-Hartree-Fock evaluations of the Weak-charge radii. We then refine the Standard Model predictions for the recent experimental results of the COHERENT experiment. We find that our cross sections are in good agreement with previous predictions, but with significantly smaller uncertainties - by up to a factor of 10. Near-future CEvNS experiments will meaningfully benefit from improved predictions through an increased sensitivity to new-physics signals.

    hep-phnucl-thPRD(2025)·17 citations
16. 16*

    The Parton Branching evolution package uPDFevolv2

    H. Jung🇩🇪 · A. Lelek🇧🇪 · K. Moral Figueroa🇩🇪 · S. Taheri Monfared🇩🇪

    uPDFevolv2 is a software package designed for evolving collinear and Transverse Momentum Dependent (TMD) parton densities using the DGLAP evolution equation. A comprehensive description of both the theoretical framework and technical implementation is given, accompanied by a detailed guide on program usage, focusing on customizable parameters. This report is as a technical release note for uPDFevolv version 2.5.03.

    hep-ph12 citations
17. 17*

    Quarkonium Polarization in Medium from Open Quantum Systems and Chromomagnetic Correlators

    Di-Lun Yang🇹🇼 · Xiaojun Yao🇺🇸

    We study the spin-dependent in-medium dynamics of quarkonia by using the potential nonrelativistic QCD (pNRQCD) and the open quantum system framework. We consider the pNRQCD Lagrangian valid up to the order $\frac{r}{M^0}=r$ and $\frac{r^0}{M}=\frac{1}{M}$ in the double power counting. By considering the Markovian condition and applying the Wigner transformation upon the diagonal spin components of the quarkonium density matrix with the semiclassical expansion, we systematically derive the Boltzmann transport equation for quarkonia with polarization dependence in the quantum optical limit. Unlike the spin-independent collision terms governed by certain chromoelectric field correlators, new gauge invariant correlators of chromomagnetic fields determine the recombination and dissociation terms with polarization dependence at the order we are working. We also derive a Lindblad equation describing the in-medium transitions between spin-singlet and spin-triplet heavy quark-antiquark pairs in the quantum Brownian motion limit. The Lindblad equation is governed by new transport coefficients defined in terms of the chromomagnetic field correlators. Our formalism is generic and valid for both weakly coupled and strongly coupled quark gluon plasmas. It can be further applied to study spin alignment of vector quarkonia in heavy ion collisions.

    hep-phnucl-thquant-phPRD(2024)·16 citations
18. 18*

    A log story short: running contributions to radiative Higgs decays in the SMEFT

    Christophe Grojean🇩🇪 · Guilherme Guedes🇩🇪 · Jasper Roosmale Nepveu🇩🇪 · Gabriel M. Salla🇧🇷

    We investigate the renormalization of the radiative decays of the Higgs to two gauge bosons in the Standard Model Effective Field Theory at mass dimension eight. Given that these are loop-level processes, their one-loop renormalization can be phenomenologically important when triggered by operators generated through the tree-level exchange of heavy particles (assuming a weakly coupled UV model). By computing the tree-level matching conditions of all relevant extensions of the Standard Model, we demonstrate that this effect is indeed present in the $h\to \gamma Z$ decay at dimension eight, even though it is absent at dimension six. In contrast, the $h\to gg$ and $h\to \gamma \gamma$ decays can only be renormalized by operators generated by one-loop processes. For UV models with heavy vectors, this conclusion hinges on the specific form of their interaction with massless gauge bosons which is required for perturbative unitarity. We study the quantitative impact of the possible logarithmic enhancement of $h\to \gamma Z$, and we propose an observable to boost the sensitivity to this effect. Given the expected increased precision of next-generation high-energy experiments, this dimension-eight contribution could be large enough to be probed and could therefore give valuable clues about new physics by revealing some of its structural features manifesting first at dimension eight.

    hep-phJHEP(2024)·18 citations
19. 19*

    Three-loop corrections to Higgs boson pair production: reducible contribution

    Joshua Davies🇬🇧 · Kay Schönwald🇨🇭 · Matthias Steinhauser🇩🇪 · Marco Vitti🇩🇪

    We compute three-loop corrections to the process $gg\to HH$ originating from one-particle reducible diagrams. This requires the computation of two-loop corrections to the gluon-gluon-Higgs vertex with an off-shell gluon. We describe in detail our approach to obtain semi-analytic results for the vertex form factors and present results for the two form factors contributing to Higgs boson pair production.

    hep-phJHEP(2024)·27 citations
20. 20*

    Parity nonconservation induced by spacetime geometry

    Arnab Chakraborty🇮🇳 · Amitabha Lahiri🇮🇳

    The interaction of fermion spin with spacetime can be non-universal, leading to a new interaction beyond the Standard Model, independent of gravitation. Fermions generate spacetime torsion, which can be integrated out in favor of a four-fermion interaction in a torsion-free background. This is a current-current interaction which involves all fermions and generically has different coupling constants for different chiralities and species of fermions. It does not vanish when curvature goes to zero, so accelerator experiments should be able to see its effect. We calculate the contribution of this geometrical interaction to parity nonconservation in $e^{-}{e}^{-}$ and $e^{-}D$ scattering and compare with known observations. This provides an estimate of an upper bound on the coupling constants, suggesting that the strength of the ``new physics'' can be as large as only one order of magnitude smaller than that of weak interactions.

    hep-phEur.Phys.J.Plus(2024)·6 citations
21. 21*

    Introductive exercises to Quantum Field Theory

    Stefano Disca · Roberto Demaria · Lorenzo Formaggio🇺🇸

    We present a collection of 12 exercises picked from the exam tests of the course "Elements of Quantum Field Theory", teached by professor Mauro Moretti in the academic year 2021-22 for the Master's Degree in Physics at the University of Ferrara. The goal of this review is to provide a general method to approach the main types of calculations in Quantum Field Theory, involving applications of Noether's theorem, checking of Ward identities, computations of cross sections and decay rates.

    hep-ph0 citations
22. 22*

    Unveiling baryon charge carriers through charge stopping in isobar collisions

    Gregoire Pihan🇺🇸 · Akihiko Monnai🇯🇵 · Björn Schenke🇺🇸 · Chun Shen🇺🇸

    Utilizing a comprehensive (3+1)D relativistic hydrodynamic framework with multiple conserved charge currents and charge-dependent Lattice-QCD-based equation of state, we study the baryon and electric charge number deposition at mid rapidity in isobar Ru+Ru and Zr+Zr collisions at the center of mass energy $\sqrt{s_{\mathrm{NN}}}=200$ GeV. Comparing our predictions with upcoming experimental data from the Relativistic Heavy Ion Collider will shed light on the existence of baryon junctions.

    ↳ nucl-thhep-phPRL(2024)·22 citations
23. 23*

    Do high redshift QSOs and GRBs corroborate JWST?

    Eoin Ó Colgáin🇮🇪 · M. M. Sheikh-Jabbari🇮🇷 · Lu Yin🇰🇷

    The James Webb Space Telescope (JWST) is reporting massive high redshift galaxies that appear challenging from the $\Lambda$CDM perspective. Interpreted as a cosmological problem, this necessitates the Planck collaboration underestimating either matter density ${\Omega }_m$ or physical matter density ${\Omega }_m{h}^2$ at higher redshifts. Through standard frequentist profile likelihoods, we identify corroborating quasar (QSO) and gamma-ray burst (GRB) data sets where ${\Omega }_m$ increases with effective redshift $z_{\text{eff}}$ and remains anomalously large at higher redshifts. We relax the traditional priors by allowing for ${\Omega }_m>1$, consistent with negative dark energy density, to locate profile likelihood peaks where possible. While the variation of ${\Omega }_m$ with $z_{\text{eff}}$ is at odds with the $\Lambda$CDM model, demarcating frequentist confidence intervals through differences in ${\chi }^2$ in profile likelihoods, the prevailing technique in the literature, points to $3.9\sigma$ and $7.9\sigma$ tensions between GRBs and QSOs, respectively, and Planck-$\Lambda$CDM. We explain the approximations inherent in the existing profile likelihood literature, and highlight fresh methodology that generalises the prescription. We show that alternative methods, including Bayesian approaches, lead to similar tensions. Finally, in the large sample limit, we show that Feldman-Cousins prescription for frequentist confidence intervals in the presence of a boundary (prior) leads to confidence intervals that are bounded above by Wilks' theorem.

    ↳ astro-ph.COgr-qchep-phPhys.Dark Univ.(2025)·29 citations
24. 24*

    LinApart: optimizing the univariate partial fraction decomposition

    Bakar Chargeishvili🇩🇪 · Levente Fekésházy🇩🇪 · Gábor Somogyi🇭🇺 · Sam Van Thurenhout🇭🇺

    We present LinApart, a routine designed for efficiently performing the univariate partial fraction decomposition of large symbolic expressions. Our method is based on an explicit closed formula for the decomposition of rational functions with fully factorized denominators. We provide implementations in both the Wolfram Mathematica and C languages, made available at https://github.com/fekeshazy/LinApart . The routine can provide very significant performance gains over available tools such as the Apart command in Mathematica.

    ↳ cs.SChep-phhep-thComput.Phys.Commun.(2025)·6 citations
25. 25*

    Anisotropic flow in fixed-target ${}^{208}$Pb+${}^{20}$Ne collisions as a probe of quark-gluon plasma

    Giuliano Giacalone🇩🇪 · Wenbin Zhao🇺🇸 · Benjamin Bally🇫🇷 · Shihang Shen🇩🇪 · Thomas Duguet🇫🇷 · Jean-Paul Ebran🇫🇷 · Serdar Elhatisari🇹🇷 · Mikael Frosini🇫🇷 · Timo A. Lähde🇩🇪 · Dean Lee🇺🇸 · Bing-Nan Lu🇨🇳 · Yuan-Zhuo Ma🇺🇸 and 10 other authors

    The System for Measuring Overlap with Gas (SMOG2) at the LHCb detector enables the study of fixed-target ion-ion collisions at relativistic energies ($\sqrt{s_{\mathrm{NN}}}\sim 100$ GeV in the centre-of-mass). With input from \textit{ab initio} calculations of the structure of ${}^{16}$O and ${}^{20}$Ne, we compute 3+1D hydrodynamic predictions for the anisotropic flow of Pb+Ne and Pb+O collisions, to be tested with upcoming LHCb data. This will allow the detailed study of quark-gluon plasma (QGP) formation as well as experimental tests of the predicted nuclear shapes. Elliptic flow ($v_2$) in Pb+Ne collisions is greatly enhanced compared to the Pb+O baseline due to the shape of ${}^{20}$Ne, which is deformed in a bowling-pin geometry. Owing to the large ${}^{208}$Pb radius, this effect is seen in a broad centrality range, a unique feature of this collision configuration. Larger elliptic flow further enhances the quadrangular flow ($v_4$) of Pb+Ne collisions via non-linear coupling, and impacts the sign of the kurtosis of the elliptic flow vector distribution ($c_2\{4\}$). Exploiting the shape of ${}^{20}$Ne proves thus an ideal method to investigate the formation of QGP in fixed-target experiments at LHCb, and demonstrates the power of SMOG2 as a tool to image nuclear ground states.

    ↳ nucl-thhep-phnucl-exPRL(2025)·64 citations
26. 26*

    Breaking into the window of primordial black hole dark matter with x-ray microlensing

    Manish Tamta🇮🇳 · Nirmal Raj🇮🇳 · Prateek Sharma🇮🇳

    Primordial black holes (PBHs) in the mass range $10^{-16}-10^{-11}{M}_{\odot }$ may constitute all the dark matter. We show that gravitational microlensing of bright x-ray pulsars provide the most robust and immediately implementable opportunity to uncover PBH dark matter in this mass window. As proofs of concept, we show that the currently operational NICER telescope can probe this window near $10^{-14}{M}_{\odot }$ with just two months of exposure on the x-ray pulsar SMC-X1, and that the forthcoming STROBE-X telescope can probe complementary regions in only a few weeks. These times are comparable to the week-long exposures obtained by NICER on various individual sources. We take into account the effects of wave optics and the finite extent of the source, which become important for the mass range of our PBHs. We also provide a spectral diagnostic to distinguish microlensing from transient background events and to broadly mark the PBH mass if true microlensing events are observed. In light of the powerful science case, i.e., the imminent discovery of dark matter searchable over multiple decades of PBH masses with achievable exposures, we strongly urge the commission of a dedicated large broadband telescope for x-ray microlensing. We derive the microlensing reach of such a telescope by assuming sensitivities of detector components of proposed missions, and find that with hard x-ray pulsar sources PBH masses down to a few $10^{-17}{M}_{\odot }$ can be probed.

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2025)·28 citations
27. 27*

    Dwarf galaxies imply dark matter is heavier than $2.2\times 10^{-21}\mathbf{eV}$

    Tim Zimmermann🇳🇴 · James Alvey🇳🇱 · David J. E. Marsh🇬🇧 · Malcolm Fairbairn🇬🇧 · Justin I. Read🇬🇧

    It is widely established that a lower bound on the dark matter particle mass, $m$, can be obtained by demanding that the de Broglie wavelength in a given galaxy must be smaller than the virial radius of the galaxy, leading to $m\gtrsim 10^{-22}\text{ eV}$ when applied to typical dwarf galaxies. This lower limit has never been derived precisely or rigorously. We use stellar kinematical data for the Milky Way satellite galaxy Leo II to self-consistently reconstruct a statistical ensemble of dark matter wavefunctions and corresponding density profiles. By comparison to a data-driven, model-independent reconstruction, and using a variant of the maximum mean discrepancy as a statistical measure, we determine that a self-consistent description of dark matter in the local Universe requires $m>2.2\times 10^{-21}\mathrm{eV}(\mathrm{CL}>95\%)$. This lower limit is free of any assumptions pertaining to cosmology, microphysics (including spin), or dynamics of dark matter, and only assumes that it is predominantly composed of a single bosonic particle species.

    ↳ astro-ph.COastro-ph.GAgr-qchep-phPRL(2025)·85 citations
28. 28*

    The eclectic flavor symmetries of ${\mathbb{T}}^2/{\mathbb{Z}}_K$ orbifolds

    Alexander Baur🇲🇽 · Hans Peter Nilles🇩🇪 · Saul Ramos-Sanchez🇲🇽 · Andreas Trautner🇩🇪 · Patrick K.S. Vaudrevange🇩🇪

    Only four ${\mathbb{T}}^2/{\mathbb{Z}}_K$ orbifold building blocks are admissible in heterotic string compactifications. We investigate the flavor properties of all of these building blocks. In each case, we identify the traditional and modular flavor symmetries, and determine the corresponding representations and (fractional) modular weights of the available massless matter states. The resulting finite flavor symmetries include Abelian and non-Abelian traditional symmetries, discrete $R$ symmetries, as well as the double-covered finite modular groups $(S_3\times S_3)⋊{\mathbb{Z}}_4$, $T^{\prime }$, $2D_3$ and $S_3\times T^{\prime }$. Our findings provide restrictions for bottom-up model building with consistent ultraviolet embeddings.

    ↳ hep-thhep-phJHEP(2024)·10 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.