Fri·Nov 29, 2024Friday·November 29, 2024

1. 01*

   An Analytic Computation of Three-Loop Five-Point Feynman Integrals

   Yuanche Liu🇨🇳 · Antonela Matijašić🇩🇪 · Julian Miczajka🇩🇪 · Yingxuan Xu🇩🇪 · Yongqun Xu🇨🇳 · Yang Zhang🇨🇳

   We evaluate the three-loop five-point pentagon-box-box massless integral family in the dimensional regularization scheme, via canonical differential equation. We use tools from computational algebraic geometry to enable the necessary integral reductions. The boundary values of the differential equation are determined analytically in the Euclidean region. To express the final result, we introduce a new representation of weight six functions in terms of one-fold integrals over the product of weight-three functions with weight-two kernels that are derived from the differential equation. Our work paves the way to the analytic computation of three-loop multi-leg Feynman integrals.

   hep-phhep-thPRD(2025)·23 citations
2. 02*

   Generating the Dark Matter mass from the QCD vacuum: A new approach to the Dark Matter-Baryon coincidence problem

   Yi Chung🇩🇪

   The comparable abundances of dark matter and baryons imply a deep connection between the dark sector and the QCD sector. In models of asymmetric dark matter, the number densities of both sectors are ensured to be similar. However, a complete solution should also include a mechanism for comparable masses. In this letter, we present a solution based on a strongly coupled chiral dark sector, featuring a light composite fermion as the dark matter. Its mass is generated through the misalignment triggered by the QCD vacuum, ensuring the mass to be at the GeV scale. The model features $\mathcal{O}(1)$ GeV dark baryon dark matter together with dark pions (axion-like particles). Moreover, a composite QCD axion naturally arise in the UV model.

   hep-ph4 citations
3. 03*

   String loop origin for dark radiation and superheavy dark matter in type IIB compactifications

   Vasileios Basiouris🇬🇷

   In this article we study the significance of string loop corrections, in a perturbative moduli stabilization scenario, focusing on their role in unraveling the origin of dark radiation in the late cosmological epoch and their correlation to dark matter. More specifically, a detailed analysis is provided in which the mass hierarchy of the normalized fields in the Kähler moduli sector is determined by the scales of the integer fluxes and the quantum corrections. Furthermore, we compute the previously underestimated contributions to the decay rates of moduli to axions, which behave as dark radiation, highlighting their connection to the aforementioned higher-order corrections. Two contrasting reheating scenarios (low-scale and high-scale) are provided, depending on the decay rate of the longest-lived particle into the Standard Model degrees of freedom through a Giudice-Masiero mechanism, while the effective number of neutrino species $\Delta N_{eff}$ remains below the respective bounds. Finally, a non-thermal dark matter scenario is proposed based on the decays of heavy scalar fields, where the main production mechanisms are investigated, leading to a dark matter candidate mass ranging from a few $GeV$ up to $10^{12}GeV$.

   hep-phhep-thPRD(2025)·2 citations
4. 04*

   Relaxing Constraints on Dark Matter Annihilation Near the Supermassive Black Hole in M87

   Mehrdad Phoroutan-Mehr🇺🇸 · Hai-Bo Yu🇺🇸

   The supermassive black hole at the center of M87 could redistribute dark matter particles within its sphere of influence, creating a high-density region known as a density spike. This spike can significantly enhance dark matter annihilation signals, making M87 a critical target for deriving stringent constraints on annihilation cross sections. In this work, we demonstrate that these constraints are highly sensitive to the choice of the halo density profile for M87. Motivated by recent kinematic studies of M87, we adopt a cored halo model and find that the constraints on dark matter annihilation are significantly relaxed. Specifically, in the cored halo scenario, the smooth part of the halo overwhelmingly dominates the annihilation signals, whereas the commonly-assumed cuspy halo model attributes a major contribution to the spike. We demonstrate this effect using a dark matter model with a light mediator.

   hep-phPRD(2025)·10 citations
5. 05*

   New renormalization scheme in extended Higgs sectors for Higgs precision measurements

   Shinya Kanemura🇯🇵 · Mariko Kikuchi🇯🇵 · Kei Yagyu🇯🇵

   We discuss a new renormalization scheme for mixing angles in extended Higgs sectors for the coming era of the Higgs precise measurements at future lepton colliders. We focus on the two Higgs doublet models (2HDMs) with a softly-broken $Z_2$ symmetry as a simple and important example, in which two mixing angles $\alpha$ and $\beta$ appear in the Higgs sector. In this new scheme, the counterterms for two mixing angles $\delta \alpha$ and $\delta \beta$ are determined by requiring that deviations in the decay rates of $h\to Z{Z}^{\ast }\to Z{\ell }^{+}{\ell }^{-}$ and $h\to \tau \tau$ from the corresponding predictions in the standard model at NLO are given by the square of the scaling factor at tree level. We show how this scheme works in the 2HDMs, and demonstrate how the other decay rates (e.g., $h\to W{W}^{\ast }$, $h\to b\bar{b}$, etc.) are predicted at NLO.

   hep-phEPJ Web Conf.(2024)·0 citations
6. 06*

   Quantum computing of chirality imbalance in SU(2) gauge theory

   Guofeng Zhang🇨🇳 · Xingyu Guo🇨🇳 · Enke Wang🇨🇳 · Hongxi Xing (QuNu Collaboration)🇨🇳

   We implement a variational quantum algorithm to investigate the chiral condensate in a 1+1 dimensional SU(2) non-Abelian gauge theory. The algorithm is evaluated using a proposed Monte Carlo sampling method, which allows the extension to large qubit systems. The obtained results through quantum simulations on classical and actual quantum hardware are in good agreement with exact diagonalization of the lattice Hamiltonian, revealing the phenomena of chiral symmetry breaking and restoration as functions of both temperature and chemical potential. Our findings underscore the potential of near-term quantum computing for exploring QCD systems at finite temperature and density in non-Abelian gauge theories.

   hep-phhep-lathep-thnucl-th+1PRD(2025)·7 citations
7. 07*

   Heavy quarkonium dissociation in the presence of magnetic field and anisotropy using dissociation energy criterion

   Rishabh Sharma🇮🇳 · Siddhartha Solanki🇮🇳 · Manohar Lal🇮🇳 · Vineet Kumar Agotiya🇮🇳

   In this article, we have studied the dissociation temperature of 1S and 2S states of heavy quarkonium in the presence of anisotropy and a strong magnetic field background using the dissociation energy criterion. We utilized the medium-modified form of the Cornell potential, which depends on temperature as well as the anisotropic parameter {\xi} and the magnetic field. The binding energy (B.E.) and dissociation energy (D.E.) of heavy quarkonium have been examined for different values of the magnetic field and anisotropy. It is noted that B.E. starts decreasing from higher values as we increase the anisotropy, while D.E. exhibits the opposite behavior. The dissociation temperature appears to increase with anisotropy, while it decreases with the magnetic field, as shown in Table 1 and 2 respectively. These results align well with recent research findings.

   hep-phnucl-thIndian J.Phys.(2025)·1 citation
8. 08*

   Simulating toponium formation signals at the LHC

   Benjamin Fuks🇫🇷 · Kaoru Hagiwara🇯🇵 · Kai Ma🇨🇳 · Ya-Juan Zheng🇯🇵

   We present a method to simulate toponium formation events at the LHC using the Green's function of non-relativistic QCD in the Coulomb gauge, which governs the momentum distribution of top quarks in the presence of the QCD potential. This Green's function can be employed to re-weight any matrix elements relevant for $t\bar{t}$ production and decay processes where a colour-singlet top-antitop pair is produced in the $S$-wave at threshold. As an example, we study the formation of ${\eta }_t$ toponium states in the gluon fusion channel at the LHC, combining the re-weighted matrix elements with parton showering.

   hep-phhep-exEPJC(2025)·53 citations
9. 09*

   Testable Flavored TeV-scale Resonant Leptogenesis with MeV-GeV Dark Matter in a Neutrinophilic 2HDM

   Peisi Huang🇺🇸 · Kairui Zhang🇺🇸

   We explore flavored resonant leptogenesis embedded in a neutrinophilic 2HDM. Successful leptogenesis is achieved by the very mildly degenerate two heavier right-handed neutrinos (RHNs), $N_2$ and $N_3$, with mass splitting of only $\Delta M_{32}/M_2\sim \mathcal{O}(0.1\%-1\%)$. The lightest RHN, with MeV-GeV-scale mass, lies below the sphaleron freeze-out temperature and remains stable, serving as a dark matter candidate. The model enables TeV-scale leptogenesis while avoiding the extreme mass degeneracy plagued conventional resonant leptogenesis. Baryon asymmetry, neutrino masses, and potentially the dark matter relic density can be addressed within a unified and experimentally testable framework.

   hep-phPRD(2025)·3 citations
10. 10*

    Sterile-active resonance: A global qualitative picture

    Mark Brettell🇬🇧 · Ivan Martinez-Soler🇬🇧 · Hisakazu Minakata🇺🇸

    In the $\nu$SM extended by adding an eV-scale sterile state, the $(3+1)$ model, the sterile-active level crossing entails the MSW resonance, here referred as the sterile-active (SA) resonance. In this paper, we construct an effective theory of SA resonance which involves only the sterile-active mixing angles and $\Delta m_{41}^2$, thanks to the given environment of high matter potential which freezes the $\nu$SM oscillations. We give our first attempt at an analytic treatment of the effective theory to illuminate the global picture of the SA resonance at a glance. We formulate a perturbative framework in which the structure of ``texture zeros'' of the $S$ matrix in the flavor space and the suppression by the small parameters $\sin {\theta }_{j4}$ ($j=1,2,3$) allows us to reveal the flavor$-$event-type hierarchy of the resonance-effect strength in the probabilities. We have shown that the cascade events dominantly comes from the three paths through $P({\nu }_e\to {\nu }_e)$, $P({\bar{\nu }}_e\to {\bar{\nu }}_e)$, and $P({\bar{\nu }}_{\mu }\to {\bar{\nu }}_{\tau })$, and a three-component fit is suggested to disentangle the SA resonance generation mechanisms.

    hep-phJHEP(2025)·2 citations
11. 11*

    Analysis of $b\to c\ell \nu$ baryonic decay modes in SMEFT approach

    Dhiren Panda🇮🇳 · Manas Kumar Mohapatra🇮🇳 · Rukmani Mohanta🇮🇳

    The flavor-changing neutral current decays of heavy bottom quark, alongside the flavor-changing charged current processes mediated by $b\to (c,u)$ in semileptonic $B$ decays are emerged as powerful tools for exploring physics beyond the Standard Model. In this work, we focus on the feasibility of interpreting the processes mediated by $b\to c\tau \nu$ transitions, in particular, the semileptonic $b$-baryonic decay modes ${\Sigma }_b\to {\Sigma }_c^{(\ast )}{\tau }^{-}{\bar{\nu }}_{\tau }$ and ${\Xi }_b\to {\Xi }_c{\tau }^{-}{\bar{\nu }}_{\tau }$ in the context of SMEFT approach. We perform a detailed analysis of the sensitivity of new physics operators on various observables such as branching ratio, forward-backward asymmetry parameter, lepton non-universal observable and the longitudinal polarization fraction of the $b$-baryonic decay channels.

    hep-phEur.Phys.J.Plus(2025)·2 citations
12. 12*

    Theorem on vacuum stability

    André Milagre🇵🇹 · Luís Lavoura🇵🇹

    We consider an extension of the Standard Model with one or more scalar multiplets beyond the Higgs doublet $\Phi$. The additional scalar multiplets are supposed to carry arbitrary hypercharges. We prove that, in such a model, if the field configuration where only $\Phi$ has a nonzero vacuum expectation value (VEV) is a local minimum of the potential, then it has a lower value of the potential than any field configuration where both $\Phi$ and other scalar multiplets have nonzero VEVs.

    hep-phhep-thPRD(2025)·1 citation
13. 13*

    Quantum field theory treatment of neutrino flavor oscillations in matter

    Maxim Dvornikov (IZMIRAN)🇷🇺

    We study neutrino oscillations in background matter within the quantum field theory formalism where neutrino mass eigenstates are virtual particles. In this case, neutrino mass eigenstates are mixed owing to the interaction with matter. Assuming that neutrinos are Majorana particles, we find the exact propagators for massive neutrinos accounting for the interaction with matter by solving the analog of the Dyson equation. These propagators are used to calculate the transition probability which coincides with the prediction of the standard quantum mechanical treatment of neutrino flavor oscillations in uniform matter. Finally, we analyze the approximations made in our analysis.

    hep-phhep-thPRD(2025)·9 citations
14. 14*

    Prospects for detecting the rare heavy Higgs decay $H\to h\gamma \gamma$ through the $H\to b\bar{b}\gamma \gamma$ channel at the LHC

    M. A. Arroyo-Ureña🇲🇽 · Alejandro Ibarra🇩🇪 · Pablo Roig🇲🇽 · T. Valencia-Pérez🇲🇽

    We study the decay of a heavy CP-even neutral Higgs into an on-shell Standard Model-like Higgs boson and two photons, $H\to h\gamma \gamma$, in the two-Higgs doublet model. We argue that the decay channel $H\to h\gamma \gamma$, followed by the decay of the Standard Model Higgs $h\to b\bar{b}$, could be observed at the 5$\sigma$ level at the High-Luminosity LHC for masses of the heavy Higgs up to 950 GeV for the type-II, 650 GeV for the Lepton Specific and the Flipped 2HDMs, and 350 GeV for the type-I. We also discuss the possible role of the decay $H\to h\gamma \gamma$ in discriminating among different types of 2HDMs and in enhancing the total number of events in the final state $H\to b\bar{b}\gamma \gamma$ compared to the cascade decay $H\to hh$ followed by $h\to \gamma \gamma$ $h\to b\bar{b}$ with identical final state (although with different kinematical distributions).

    hep-phhep-exJHEP(2025)·1 citation
15. 15*

    Looking into the quantum entanglement in $H\to Z{Z}^{\star }$ at LHC within SMEFT framework

    Amir Subba🇮🇳 · Ritesh K. Singh🇮🇳 · Rohini M. Godbole🇮🇳

    We study $H\to Z{Z}^{\star }$ production process in final four lepton states at $13$ TeV LHC in SMEFT framework. The anomalous $HZZ$ couplings are parameterized with dimension-6 $SU(2{)}_L\times U(1{)}_Y$ gauge invariant operators. We compute the eight polarizations of each $Z$ boson and $64$ spin-correlations as asymmetries in angular functions of final decayed leptons in the rest frame of the $Z$ boson. These asymmetries are further used to construct the joint density matrix (DM) for $Z{Z}^{\star }$ system. However, such DM suffers from negative probability and eigenvalues. To alleviate the negativity issues, we reconstruct the DM using asymmetries of symmetrized angular functions owing to the indistinguishability of two $Z$ bosons. The symmetrized DM is further employed to compute lower bound for concurrence as a witness of entanglement measurable at the collider experiments. The $Z{Z}^{\star }$ system is found to be in an entangled state for all values of the anomalous couplings. Notably, while the lower bound exhibits poorer sensitivity to anomalous couplings compared to asymmetries, it demonstrates distinct behavior for CP-even and odd couplings.

    hep-phhep-th21 citations
16. 16*

    Ensuring that toponium is glued, not nailed

    Felipe J. Llanes-Estrada🇪🇸

    Hints of toponium might be incipient in LHC data, as given the vast numbers of t quarks produced, some survive on the exponential-decay tail long enough to fasten ttbar together. I here discuss a few differences between the standard Quantum Chromodynamics (QCD) binding (the ``glue'') and exotic short-range binding (the ``nail''). If the binding energy below threshold reaches the 3 GeV range the peak of the eta_t is distinct enough that a cross-section dip should be apparent in the line shape, should there only be one isolated resonance, but is filled by the excited QCD states adding about a pbarn to the cross section of ttbar production. Their effect for smaller binding energies is a tenuous increase in the cross section. A new-physics short-range interaction, on the other hand, yields a larger cross-section for equal binding energy (or hardly a visible bound state for similar cross section). This is due to its larger ttbar relative wavefunction at small distances. Finally, assuming that standard QCD plays out, I comment on what size of constraints on new-physics coefficients one can expect at given precision.

    hep-phPLB(2025)·18 citations
17. 17*

    Dark axion portal at $Z$ boson factories

    Krzysztof Jodłowski🇰🇷

    Dark axion portal connects an axion-like-particle (ALP), which can be the QCD axion, with the SM by the coupling to a photon and a dark photon, leading to a rich and distinct phenomenology related to dark matter, astrophysics, and cosmology. We note that due to the gauge invariance, the $Z$ boson-dark photon-ALP coupling should also be generated with sizable strength, and we study its phenomenological consequences at $Z$ boson factories: LEP, FCC-ee, and forward physics detectors at the LHC and FPF@FCC - FASER and MATHUSLA. Due to the large number of $Z$ bosons produced, DAP particles can be efficiently produced and detected by semi-visible displaced decays of the heavier DS species to $\gamma$+inv. or $f^{+}{f}^{-}$+inv., and via missing energy signature with zero or one photon. Because of the complementarity of the two approaches, we find great prospects in exploring both short and long-lived lifetime regimes of DAP, especially when the heavier dark species has mass above $0.1$GeV.

    hep-phJHEP(2025)·11 citations
18. 18*

    Light quark fragmentation into S-wave fully charmed tetraquark

    Xiao-Wei Bai🇨🇳 · Yingsheng Huang🇺🇸 · Wen-Long Sang🇨🇳

    We compute the fragmentation function of a light quark into S-wave fully-charmed tetraquarks ($T_{4c}$) within the nonrelativistic QCD (NRQCD) framework, at leading order in ${\alpha }_s$ and $v$. We present results for light quark fragmentation into $T_{4c}$ and predict its contribution to $T_{4c}$ production at high transverse momentum ($p_T$) at the LHC and EIC. We also compare light quark fragmentation with charm quark and gluon fragmentation channels. Our analysis shows that the production cross section for $T_{4c}$ from light quark fragmentation is smaller than that from gluon fragmentation but larger than that from charm quark fragmentation.

    hep-phPRD(2025)·17 citations
19. 19*

    Generalized Lindblad master equation for neutrino evolution

    Konstantin Stankevich🇷🇺 · Alexander Studenikin🇷🇺 · Maksim Vyalkov🇷🇺

    A new theoretical framework, based on the quantum field theory of open systems applied to neutrinos, has been developed. This framework aims to describe the neutrino evolution in external environment, taking into account the effect of neutrino quantum decoherence. We have applied this approach to investigate a novel mechanism for neutrino quantum decoherence, which arises due to the neutrino decay into a lighter neutrino state and a massless particle, as well as the inverse process of absorption of a massless particle by a neutrino. We derived the new generalized Lindblad master equation for the neutrino evolution that accounts for neutrino transitions between states with different momenta. We also demonstrate that studying of neutrino quantum decoherence through this master equation provides a unique possibility to determine or limit the neutrino decay width. On this basis we obtained the constraint on neutrino lifetime $\frac{{\tau }_2}{m_2}>1.83\times 10^{-10}\frac{s}{eV}$ (for the case of the Dirac neutrino scalar decay and neutrino degenerate hierarchy).

    hep-phPRD(2025)·10 citations
20. 20*

    Axion-induced pair production: a new strategy for axion detection

    Fernando Arias-Aragón🇮🇹 · Maurizio Giannotti🇪🇸 · Giovanni Grilli di Cortona🇮🇹 · Federico Mescia🇮🇹

    We revisit and update the axion-induced pair production process in a nuclear electric field mediated by the axion-electron coupling, $a+{}_Z^{A}X\to {}_Z^{A}X+e^{+}+e^{-}$. This process emerges as one of the most efficient channels for detecting axions with energies above a few MeV in large underground detectors. It is particularly relevant for detecting axions produced in nuclear reactions, such as the $p+d\to {}^3\mathrm{He}+a(5.5\mathrm{MeV})$ reaction in the solar pp-chain, and for axions originating in supernovae. Despite recent interest in detecting high-energy axions, the pair production process has received limited attention, even in scenarios where it is the dominant detection channel. This study fills this gap by demonstrating that pair production is a highly effective detection mechanism for high-energy axions. We apply our results to axions from supernovae and the solar 5.5 MeV line, recasting the current bounds of Borexino and comparing the detection capabilities of the JUNO and Hyper-Kamiokande detectors.

    hep-phhep-exPRD(2025)·20 citations
21. 21*

    Constraints on the dark matter-baryon interaction cross section from galaxy cluster thermodynamics

    Eleanor Stuart🇺🇸 · Kris Pardo🇺🇸

    Dark matter (DM) models with a non-zero DM-baryon interaction cross section imply energy transfer between DM and baryons. We present a new method of constraining the DM-baryon interaction cross section and DM particle mass for velocity-independent interactions using the thermodynamics of galaxy clusters. If the baryonic gas in these clusters is in thermodynamic equilibrium and DM cools baryons, this cooling rate is limited by the net heating rate of other mechanisms in the cluster. We use the REFLEX clusters from the Meta-Catalogue of X-ray detected Clusters of Galaxies (MCXC) with mass estimates from the Atacama Cosmology Telescope (ACT) catalog of Sunyaev-Zel'dovich (SZ) selected galaxy clusters. This yields 95% upper bounds on the DM-proton interaction cross section for velocity-independent interactions of ${\sigma }_0\le 9.3\times 10^{-28}\mathrm{c}{\mathrm{m}}^2$ for DM masses, $m_{\chi }=10^{-4}-10^{-1}$ GeV. These constraints are within an order of magnitude of the best constraints derived in this mass range, and serve as a complementary, independent constraint. We also apply this model to the fractional interacting DM scenario, where only 10% and 1% of the DM is interacting. Unlike other methods, this constraint scales linearly with this fraction. This yields 95% upper bounds of ${\sigma }_0\le 1.1\times 10^{-26}\mathrm{c}{\mathrm{m}}^2$ and ${\sigma }_0\le 8.2\times 10^{-26}\mathrm{c}{\mathrm{m}}^2$, which are the strongest existing constraints for this scenario. This paper serves as a proof of concept. Upcoming SZ measurements will provide temperature profiles for galaxy clusters. Combining these measurements with more complex thermodynamic models could lead to more robust constraints.

    ↳ astro-ph.COhep-phJCAP(2026)·4 citations
22. 22*

    New Limits on Coherent Neutrino Nucleus Elastic Scattering Cross Section at the Kuo-Sheng Reactor Neutrino Laboratory

    TEXONO Collaboration: S. Karmakar🇹🇼 · M.K. Singh🇹🇼 · V. Sharma🇹🇼 · H.T. Wong🇹🇼 · Greeshma C.🇹🇼 · H.B. Li🇹🇼 · L. Singh🇮🇳 · M. Agartioglu🇹🇼 · J.H. Chen🇨🇳 · C.I. Chiang🇹🇼 · M. Deniz🇹🇼 · H.C. Hsu🇹🇼 and 16 other authors

    Neutrino nucleus elastic scattering ({\nu}Ael) with reactor neutrinos is an interaction under full quantum-mechanical coherence. It has not yet been experimentally observed. We present new results on the studies of {\nu}Ael cross section with an electro-cooled p-type point-contact germanium detector at the Kuo-Sheng Reactor Neutrino laboratory. A total of (242)357 kg-days of Reactor ON(OFF) data at a detector threshold of 200 eVee in electron equivalent unit are analyzed. The Lindhard model parametrized by a single variable k which characterizes the quenching function was used. Limits at 90% confidence level are derived on the ratio {\rho} relative to standard model (SM) cross section of {\rho}<4.7 at the predicted value of k=0.162, while k<0.285 at the SM-value of {\rho}=1. Prospects on future positive measurements are discussed.

    ↳ nucl-exhep-exhep-phPRL(2025)·37 citations
23. 23*

    Constraints on the primordial curvature power spectrum at small scales between $3\times 10^{18}$ and $4.5\times 10^{21}\mathrm{Mp}{\mathrm{c}}^{-1}$

    Yupeng Yang🇨🇳

    The primordial curvature power spectrum ${\mathcal{P}}_{\mathcal{R}}$ has been measured with high precision on large scales $10^{-4}\lesssim k\lesssim 3\mathrm{Mp}{\mathrm{c}}^{-1}$ based on observations of the cosmic microwave background, Lyman-$\alpha$ forest and large scale structure. On small scales $3\lesssim k\lesssim 10^{23}\mathrm{Mp}{\mathrm{c}}^{-1}$, constraints are primarily derived from studies on primordial black holes (PBHs). In particular, for very small scales $10^{17}\lesssim k\lesssim 10^{23}\mathrm{Mp}{\mathrm{c}}^{-1}$, current limits come exclusively from investigations of the lightest supersymmetric particles produced by PBH radiation and the stable Planck-mass relics after their evaporation. Recent findings also indicate that the evaporation of light PBHs ($M_{\mathrm{PBH}}\lesssim 10^9\mathrm{g}$) can modify the expansion rate of the Universe and the baryon-to-photon ratio, thereby affecting the primordial abundance of light nuclei. Moreover, it has been proposed that the ``memory burden'' effect can slow down the mass loss rate of black holes, allowing light PBHs to survive until today. Based on recent theoretical advancements in black hole physics and existing constraints on the initial mass fraction of light PBHs with masses $10^3\lesssim M_{\mathrm{PBH}}\lesssim 2\times 10^9\mathrm{g}$, and especially the recent constraints on memory-burdened PBHs, we derive new and tighter upper limits on ${\mathcal{P}}_{\mathcal{R}}$ on small scales $3\times 10^{18}\lesssim k\lesssim 4.5\times 10^{21}\mathrm{Mp}{\mathrm{c}}^{-1}$, a regime that has been underexplored in previous literature. These constraints are derived under the specific assumption that the memory burden effect activates after the PBH loses half of its initial mass and subsequently halts further evaporation, and different assumptions on the memory burden parameters would lead to modified limits.

    ↳ astro-ph.COgr-qchep-phEur.Phys.J.Plus(2026)·0 citations
24. 24*

    Enhanced nuclear Schiff and electric dipole moments in nuclei with an octupole deformation

    V. V. Flambaum🇦🇺 · A. J. Mansour🇦🇺

    Deformed nuclei exhibit enhanced moments that violate time-reversal invariance ($T$) and parity ($P$). This paper focuses on the enhanced nuclear electric dipole moment (EDM) and Schiff moment present in nuclei with octupole deformation (pear-shaped nuclei). These moments, which are proportional to the octupole deformation, have a collective nature and are large in the intrinsic frame that rotates with the nucleus. However, in a state with definite angular momentum and parity, $T$ and $P$ conservation forbid their expectation values in the laboratory frame, as nuclear rotation causes them to vanish. In nuclei with octupole deformation, close opposite-parity rotational states with identical spin are mixed by $T$,$P$-violating nuclear forces. This mixing polarises the nuclear axis along the nuclear spin, allowing moments from the intrinsic frame to manifest in the laboratory frame, provided the nuclear spin $I$ is sufficiently large. Using half-life data for $E1$ transitions from the NuDat database, we calculate the intrinsic nuclear EDM $d_{\text{int}}$ for a range of nuclei theorised to exhibit octupole deformation. From these values, we independently estimate the intrinsic nuclear Schiff moment $S_{\text{int}}$ and the octupole deformation parameter ${\beta }_3$. Finally, we compare the magnitude of these collective moments in the laboratory frame with the contributions from valence nucleons, providing an estimate of the nuclear EDM and Schiff moment components unrelated to octupole deformation. The uncertainty of our estimates may exceed a factor of 10.

    ↳ nucl-thhep-phphysics.atom-phPRC(2025)·5 citations
25. 25*

    The spectra of a radiative reprocessing outflow model for fast blue optical transients

    Chun Chen (SYSU) · Rong-Feng Shen (SYSU)

    The radiation reprocessing model, in which an optically-thick outflow absorbs the high-energy emission from a central source and re-emits in longer wavelengths, has been frequently invoked to explain some optically bright transients, such as fast blue optical transients (FBOTs) whose progenitor and explosion mechanism are still unknown. Previous studies on this model did not take into account the frequency dependence of the opacity. We study the radiative reprocessing and calculate the UV-optical-NIR band spectra from a spherical outflow composed of pure hydrogen gas, for a time-dependent outflowing mass rate. Electron scattering and frequency-dependent bound-free, free-free opacities are considered. The spectrum deviates from the blackbody at NIR and UV frequencies; in particular, it has $\nu L_{\nu }\propto {\nu }^{1.5}$ at NIR frequencies, because at these frequencies the absorption optical depth from the outflow's outer edge to the so-called photon trapping radius is large and is frequency dependent. We apply our model to the proto-type FBOT AT2018cow by {the spectra} to the observed SED. The best-fit mass loss rate suggests that the total outflow mass in AT2018cow is $M_{\mathrm{out}}\approx 5.7_{-0.4}^{+0.4}{M}_{\odot }$. If that equals the total mass lost during an explosion, and if the progenitor is a blue supergiant (with a pre-explosion mass of $\sim 20M_{\odot }$), then it will suggest that the central compact remnant mass is at least $\approx 14{\mathrm{M}}_{\odot }$. This would imply that the central remnant is a black hole.

    ↳ astro-ph.HEastro-ph.GAastro-ph.SRhep-phApJ(2025)·7 citations
26. 26*

    On the photon self-energy to three loops in QED

    Felix Forner🇩🇪 · Christoph Nega🇩🇪 · Lorenzo Tancredi🇩🇪

    We compute the photon self-energy to three loops in Quantum Electrodynamics. The method of differential equations for Feynman integrals and a complete $ϵ$-factorization of the former allow us to obtain fully analytical results in terms of iterated integrals involving integration kernels related to a K3 geometry. We argue that our basis has the right properties to be a natural generalization of a canonical basis beyond the polylogarithmic case and we show that many of the kernels appearing in the differential equations, cancel out in the final result to finite order in $ϵ$. We further provide generalized series expansions that cover the whole kinematic space so that our results for the self-energy may be easily evaluated numerically for all values of the momentum squared. From the local solution at $p^2=0$, we extract the photon wave function renormalization constant in the on-shell scheme to three loops and confirm its agreement with previously obtained results.

    ↳ hep-thhep-phJHEP(2025)·37 citations
27. 27*

    Updated determination of light-cone distribution amplitudes of octet baryons in lattice QCD

    G.S. Bali🇩🇪 · V.M. Braun🇩🇪 · S. Bürger🇩🇪 · M. Göckeler🇩🇪 · M. Gruber🇩🇪 · F. Kaiser🇩🇪 · B.A. Kniehl🇩🇪 · O.L. Veretin🇩🇪 · P. Wein🇩🇪

    We present updated results on the wave function normalization constants and the first moments of the light cone distribution amplitudes for the lowest-lying baryon octet. The analysis is carried out on a large number of $n_f=2+1$ lattice gauge ensembles, including ensembles at physical pion (and kaon) masses. These are spread across five different lattice spacings, enabling a controlled continuum limit. The main differences with respect to our earlier work are the use of two-loop conversion factors to an $\overline{\mathrm{MS}}$-like scheme and of an updated set of low-energy constants in the parametrization of the quark mass dependence. As a byproduct, for the first time, the anomalous dimensions for local three-quark operators with one derivative are obtained.

    ↳ hep-lathep-phPRD(2025)·16 citations
28. 28*

    Towards a String Realization of the Dark Dimension via T-folds

    Guo-En Nian🇳🇱 · Stefan Vandoren🇳🇱

    In this work, we explore the feasibility of realizing the Dark Dimension Scenario through T-fold compactifications on $T^5\times S^1$, where the base of the internal space $S^1$ naturally acts as the requisite mesoscopic extra dimension. Utilizing Scherk--Schwarz reduction from 5D to 4D, and applying duality twists from both elliptic and parabolic conjugacy classes of subgroups of the T-duality group associated with $T^5$, we stabilize the volume of $T^5$ and several other moduli. This approach generates a potential characterized by two runaway directions, one aligned with the Scherk--Schwarz radion. Further stabilization efforts yield a decreasing potential trajectory demanded by the Dark Dimension Scenario.

    ↳ hep-thgr-qchep-phJHEP(2025)·3 citations
29. 29*

    Impact of memory-burdened black holes on primordial gravitational waves in light of Pulsar Timing Array

    Peter Athron🇨🇳 · Marco Chianese🇮🇹 · Satyabrata Datta🇨🇳 · Rome Samanta🇮🇹 · Ninetta Saviano🇮🇹

    Blue-tilted Gravitational Waves (BGWs) have been proposed as a potential candidate for the cosmic gravitational waves detected by Pulsar Timing Arrays (PTA). In the standard cosmological framework, BGWs are constrained in their frequency range by the Big Bang Nucleosynthesis (BBN) limit on GW amplitude, which precludes their detection at interferometer scales. However, introducing a phase of early matter domination dilutes BGWs at higher frequencies, ensuring compatibility with both the BBN and LIGO constraints on stochastic GWs. This mechanism allows BGWs to align with PTA data while producing a distinct and testable GW signal across a broad frequency spectrum. Ultralight Primordial Black Holes (PBHs) could provide the required early matter-dominated phase to support this process. Interpreted through the lens of BGWs, the PTA results offer a way to constrain the parameter space of a new scenario involving modified Hawking radiation, known as the ``memory burden" effect, associated with ultralight PBHs. This interpretation can be further probed by high-frequency GW detectors. Specifically, we demonstrate that PBHs as light as $10^{2-3}\mathrm{g}$ can leave detectable imprints on BGWs at higher frequencies while remaining consistent with PTA observations.

    ↳ astro-ph.COgr-qchep-phJCAP(2025)·31 citations
30. 30*

    Cosmic Topological Defects from Holography

    Francesco Bigazzi🇮🇹 · Aldo L. Cotrone🇮🇹 · Andrea Olzi🇮🇹

    This work investigates cosmic topological defects in gauge theories, focusing on models with an $SU(N)$ gauge group coupled with a single flavor, explored through a holographic framework. At low energies, the effective theory is described by an axion-like particle resulting from the spontaneous breaking of the axial $U(1{)}_A$ flavor symmetry. As the Universe cools below a critical temperature, the chiral symmetry is broken, and non-trivial vacuum configurations form, resulting in the creation of cosmic strings and domain walls. We provide a UV description of these defects in a particular holographic theory, the Witten-Sakai-Sugimoto model, as probe D6-branes. We show the presence of a first-order phase transition separating string loop from domain wall solutions. String loops charged under the baryon symmetry and with angular momentum - vortons - can be understood as excitations of a topological phase of matter given by a Chern-Simons theory living on the D6-brane world volume. Finally, we provide an effective description of string loops and vortons in terms of degrees of freedom living on the flavor brane, i.e. mesonic modes.

    ↳ hep-thhep-phJHEP(2025)·4 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.