Mon·Apr 7, 2025Monday·April 7, 2025

1. 01*

   No Dark Matter Axion During Minimal Higgs Inflation

   Claire Rigouzzo🇬🇧 · Sebastian Zell🇩🇪

   We study minimal versions of Higgs inflation in the presence of a massless QCD axion. While the inflationary energy scale of the metric variant is too high to accommodate isocurvature bounds, it was argued that Palatini Higgs inflation could evade these constraints. We show, however, that an energy-dependent decay constant enhances isocurvature perturbations, implying that axions can at most constitute a tiny fraction $<10^{-5}$ of dark matter. This conclusion can be avoided in Einstein-Cartan gravity by an additional coupling of the axion to torsion, albeit for a very specific choice of parameters. Analogous constraints as well as the possibility to alleviate them are relevant for all inflationary models with a non-minimal coupling to gravity.

   hep-phastro-ph.COgr-qchep-thPRD(2026)·7 citations
2. 02*

   Tensor hybrid charmonia

   S. S. Agaev🇦🇿 · K. Azizi🇮🇷 · H. Sundu🇹🇷

   The mass and current coupling of the tensor hybrid charmonia $H_{\mathrm{c}}$ and ${\tilde{H}}_{\mathrm{c}}$ with quantum numbers $J^{\mathrm{PC}}=2^{-+}$ and $2^{++}$, as well as their full widths are calculated in the context of the QCD sum rule method. The spectral parameters of these states are computed using the QCD two-point sum rule approach including dimension-12 terms $\sim ⟨g_s^3{G}^3{⟩}^2$. The full decay widths of the charmonia $H_{\mathrm{c}}$ and ${\tilde{H}}_{\mathrm{c}}$ are evaluated by considering their kinematically allowed decay channels. In the case of the hybrid state $H_{\mathrm{c}}$ decays to $D^{(\pm )}{D}^{\ast (\mp )}$, $D^0{\overline{D}}^{\ast 0}$, and $D_s^{(\pm )}{D}_s^{\ast (\mp )}$ mesons are taken into account. The processes ${\tilde{H}}_{\mathrm{c}}\to D^{(\ast )+}{D}^{(\ast )-}$, $D^{(\ast )0}{\overline{D}}^{(\ast )0}$, and $D_s^{(\ast )+}{D}_s^{(\ast )-}$ are employed to estimate the full width of the hybrid charmonium ${\tilde{H}}_{\mathrm{c}}$. The partial widths of these decays are computed by means of the QCD three-point sum rule method which is necessary to calculate strong couplings at the relevant hybrid-meson-meson vertices. Our predictions $m=(4.16\pm 0.14)\mathrm{GeV}$ , and $\tilde{m}=(4.5\pm 0.1)\mathrm{GeV}$ for the masses and $\Gamma \left[H_{\mathrm{c}}\right]=(160\pm 30)\mathrm{MeV}$, and $\Gamma \left[{\tilde{H}}_{\mathrm{c}}\right]=(206\pm 33)\mathrm{MeV}$ for the full width of these hybrid charmonia can be useful to study and interpret various resonances in the $4-5\mathrm{GeV}$ mass range.

   hep-phhep-exhep-latPRD(2025)·10 citations
3. 03*

   Search for anomalous quartic gauge couplings in the process ${\mu }^{+}{\mu }^{-}\to \bar{\nu }\nu \gamma \gamma$ with a nested local outlier factor

   Ke-Xin Chen🇨🇳 · Yu-Chen Guo🇨🇳 · Ji-Chong Yang🇨🇳

   In recent years, with the increasing luminosities of colliders, handling the growing amount of data has become a major challenge for future new physics~(NP) phenomenological research. To improve efficiency, machine learning algorithms have been introduced into the field of high-energy physics. As a machine learning algorithm, the local outlier factor~(LOF), and the nested LOF~(NLOF) are potential tools for NP phenomenological studies. In this work, the possibility of searching for the signals of anomalous quartic gauge couplings~(aQGCs) at muon colliders using the NLOF is investigated. Taking the process ${\mu }^{+}{\mu }^{-}\to \nu \bar{\nu }\gamma \gamma$ as an example, the signals of dimension-8 aQGCs are studied, expected coefficient constraints are presented. The event selection strategy uses unsupervised anomaly scores, with supervised optimization for EFT sensitivity. The NLOF algorithm is shown to outperform the k-means based anomaly detection methods, and a traditional counterpart.

   hep-phSciPost Phys.Core(2025)·3 citations
4. 04*

   Octaquarks in a simple chromomagnetic model

   Aaron Park🇰🇷

   In this work, we study the octaquark, which is composed of two baryons and one meson using a simple chromomagnetic model. First, we construct the wave function of the octaquark satisfying the Pauli exclusion principle in the flavor SU(3) breaking case. In order to calculate the binding energy, we consider the lowest threshold by taking into account the decay products. By calculating the color-spin interaction of octaquarks for all possible quantum numbers, we determine several candidates for compact octaquarks.

   hep-ph0 citations
5. 05*

   Optimal Observables for the Chiral Magnetic Effect from Machine Learning

   Yuji Hirono🇯🇵 · Kazuki Ikeda🇺🇸 · Dmitri E. Kharzeev🇺🇸 · Ziyi Liu🇨🇳 · Shuzhe Shi🇨🇳

   The detection of the Chiral Magnetic Effect (CME) in relativistic heavy-ion collisions remains challenging due to substantial background contributions that obscure the expected signal. In this Letter, we present a novel machine learning approach for constructing optimized observables that significantly enhance CME detection capabilities. By parameterizing generic observables constructed from flow harmonics and optimizing them to maximize the signal-to-background ratio, we systematically develop CME-sensitive measures that outperform conventional methods. Using simulated data from the Anomalous Viscous Fluid Dynamics framework, our machine learning observables demonstrate up to 90\% higher sensitivity to CME signals compared to traditional $\gamma$ and $\delta$ correlators, while maintaining minimal background contamination. The constructed observables provide physical insight into optimal CME detection strategies, and offer a promising path forward for experimental searches of CME at RHIC and the LHC.

   hep-phnucl-exnucl-thPRC(2025)·1 citation
6. 06*

   Relativistic dynamics of charmonia in strong magnetic fields

   Liuyuan Wen🇨🇳 · Meijian Li🇪🇸 · Yiyu Zhou🇮🇹 · Yang Li🇨🇳 · James P. Vary🇺🇸

   We investigate the properties of charmonium systems in strong external magnetic fields using a relativistic light-front Hamiltonian approach within the Basis Light-Front Quantization (BLFQ) framework. By solving the eigenvalue problem for the invariant mass squared operator with confinement potentials and one-gluon-exchange interactions, we obtain the mass spectrum and wave functions under varying magnetic fields. Our results reveal significant spectral modifications via the Zeeman effect, including ${\eta }_c$-$J/\psi$ mixing and magnetic sublevel splitting. Momentum density analysis demonstrates wave function deformation, with transverse momentum broadening and longitudinal narrowing under strong fields, alongside structural shifts in parton distributions such as double-hump profiles in excited states. Relativistic corrections and center-of-mass coupling critically drive these dynamics, highlighting the necessity of a relativistic framework for QCD bound states in extreme magnetic environments.

   hep-phnucl-thphysics.atom-phPRD(2025)·6 citations
7. 07*

   BitHEP -- The Limits of Low-Precision ML in HEP

   Claudius Krause🇦🇹 · Daohan Wang🇦🇹 · Ramon Winterhalder🇮🇹

   The increasing complexity of modern neural network architectures demands fast and memory-efficient implementations to mitigate computational bottlenecks. In this work, we evaluate the recently proposed BitNet architecture in HEP applications, assessing its performance in classification, regression, and generative modeling tasks. Specifically, we investigate its suitability for quark-gluon discrimination, SMEFT parameter estimation, and detector simulation, comparing its efficiency and accuracy to state-of-the-art methods. Our results show that while BitNet consistently performs competitively in classification tasks, its performance in regression and generation varies with the size and type of the network, highlighting key limitations and potential areas for improvement.

   hep-phcs.LGhep-exSciPost Phys.(2026)·9 citations
8. 08*

   Two-pole structures in QCD -- a universal phenomenon governed by chiral dynamics

   Jia-Ming Xie🇨🇳 · Jun-Xu Lu🇨🇳 · Li-Sheng Geng🇨🇳 · Bing-Song Zou🇨🇳

   We illustrate how the two-pole structures of the $\Lambda (1405)$ emerge from the underlying universal chiral dynamics that describe the coupled-channel interactions between octet baryons and pseudo-Nambu-Goldstone bosons. Specifically, we attribute this phenomenon to the form of the leading-order chiral potential, which is of the Weinberg-Tomozawa type. We reveal how the underlying chiral dynamics can be exposed by examining the light-quark mass evolution of the two poles. The latest lattice QCD simulations have indeed found evidence for the existence of the two poles of $\Lambda (1405)$, in qualitative agreement with our predictions. We briefly mention a recent work in which lattice QCD simulations are studied more quantitatively, along with a proposal for how the SU(3) flavor content of the two poles of $\Lambda (1405)$ can be experimentally verified.

   hep-phhep-latPoS(2026)·2 citations
9. 09*

   Hybrid framework of Fermi-Dirac spin hydrodynamics

   Zbigniew Drogosz🇵🇱

   We outline the hybrid framework of spin hydrodynamics, combining classical kinetic theory with the Israel-Stewart method of introducing dissipation. We obtain the local equilibrium expressions for the baryon current, the energy-momentum tensor, and the spin tensor of particles with spin 1/2 following the Fermi-Dirac statistics and compare them with the previously derived versions where the Boltzmann approximation was used. The expressions in the two cases have the same form, but the coefficients are governed by different functions. The relative differences between the tensor coefficients in the Fermi-Dirac and Boltzmann cases are found to grow exponentially with the baryon chemical potential. In the proposed formalism, nonequilibrium processes are studied including mathematically possible dissipative corrections. Standard conservation laws are applied, and the condition of positive entropy production allows for transfer between the spin and orbital parts of angular momentum.

   hep-phnucl-thMDPI Physics(2025)·3 citations
10. 10*

    Probing Gauged $U(1)$ Sub-GeV Dark Matter via Cosmic Ray Cooling in Active Galactic Nuclei

    Arvind Kumar Mishra🇨🇳 · Ning Liu🇨🇳 · Chih-Ting Lu🇨🇳

    Cosmic rays (CRs) traversing the dark matter (DM) spike surrounding active galactic nuclei (AGNs) can be cooled through interactions with DM particles. In this study, we investigated constraints on sub-GeV DM particles charged under various $U(1)$ gauge symmetries by exploiting the cooling effect of CRs in AGNs. We find that for low DM and mediator masses, the CR cooling rate is higher compared to the standard model cooling process. Furthermore, by utilizing constraints from the CR cooling effect in NGC 1068 and TXS 0506+056, we explore the bounds on the DM-electron and DM-proton elastic scattering cross-sections. Our results indicate that in the sub-GeV DM mass range, these constraints are more stringent than those from certain boosted DM mechanisms and current direct detection limits.

    hep-phastro-ph.COastro-ph.HEgr-qcPhys.Dark Univ.(2025)·15 citations
11. 11*

    Exact Wigner function for chiral spirals

    Samapan Bhadury🇵🇱 · Wojciech Florkowski🇵🇱 · Sudip Kumar Kar🇵🇱 · Valeriya Mykhaylova🇵🇱

    The exact solution of the Dirac equation for fermions coupled to an external periodic chiral condensate (chiral spiral) is used to obtain the exact formula for the Wigner function (up to the quantum loop corrections). We find that the resulting expressions for various coefficients of the Wigner function exhibit properties that cannot be reproduced within the standard semiclassical expansion. The formula for the axial vector component of the Wigner function can be conveniently used to study spin polarization effects and illustrate connections between the spin density matrix and axial current. In particular, we find that during an adiabatic change of the periodic potential into a uniform one, the polarization vector is twisted from its original direction.

    hep-phnucl-thPRD(2025)·1 citation
12. 12*

    Support for Gravitationally-Attractive Composite Antimatter and Gravitationally-Repulsive Non-composite Antimatter

    Giovanni Maria Piacentino🇮🇹 · Anthony Palladino🇺🇸

    The ALPHA collaboration recently published the article "Observation of the effects of gravity on the motion of antimatter" in issue 621 of Nature (2023), in which their conclusion states that "The probability that our data are consistent with repulsive gravity is so small as to be quantitatively meaningless (less than $10^{-15}$). Consequently, we can rule out the existence of repulsive gravity of magnitude 1$g$ between the Earth and antimatter." Indeed, their experiment proved that antihydrogen falls toward the Earth. Antihydrogen, however, is a composite particle and its mass, like that of the proton, is dominated by the mass of its binding energy. In this paper, we point out that their experiment only measures the gravitational effect on composite antimatter, and not free or valence antimatter particles such as antiquarks or antileptons. Here, we review the various theoretical frameworks supporting the possibility that valence antiquarks experience a repulsion of the order $g$ by the Earth's gravitational field. We show that the ALPHA collaboration's recent result may actually be consistent with a repulsive gravitational component of about 15%. Next, we review our concept for a direct interaction experiment between antiquarks and the Earth's gravitational field, which should be capable of providing irrefutable evidence of the gravitational repulsion of non-composite antiparticles. Finally, we suggest that existing data, collected by AMS-01 of daughter particles from cosmic protons interacting with the Mir space station, may help demonstrate the feasibility of our proposed experiment.

    hep-phhep-ex1 citation
13. 13*

    Baryogenesis from cosmological CP breaking

    Mateusz Duch🇮🇹 · Alessandro Strumia🇮🇹 · Arsenii Titov🇮🇹

    We show that baryogenesis can arise from the cosmological evolution of a scalar field that governs CP-violating parameters, such as the Yukawa couplings and the theta terms of the Standard Model. During the big bang, this scalar may reach a CP-violating minimum, where its mass can be comparable to the inflationary Hubble scale. Such dynamics can emerge in theories featuring either a spontaneously broken local U(1) symmetry or modular invariance. The latter arises naturally as the effective field theory capturing the geometric origin of CP violation in toroidal string compactifications. Modular baryogenesis is compatible with the modular approach to resolving the strong CP problem.

    hep-phastro-ph.COhep-thJHEP(2025)·9 citations
14. 14*

    Supercooled Goldstone Bosons at the QCD Chiral Phase Transition

    Adrien Florio🇩🇪 · Eduardo Grossi🇮🇹 · Aleksas Mazeliauskas🇩🇪 · Alexander Soloviev🇸🇮 · Derek Teaney🇺🇸

    We discuss a universal non-equilibrium enhancement of long-wavelength Goldstone bosons induced by quenches to the broken phase in Model G -- the dynamical universality class of an $O(4)$-antiferromagnet and the chiral phase transition in QCD. Scaling arguments for the coarsening dynamics describing the formation of the chiral condensate predict a parametric enhancement in the infrared spectra of Goldstones, a prediction confirmed by stochastic simulations of the transition. The details of the enhancement are determined by the non-linear dynamics of a superfluid effective theory, which is a limit of Model G reflecting the broken $O(4)$ symmetry. Our results translate to a parametric enhancement of low-momentum pions in heavy-ion collisions at the LHC, which are underpredicted in current hydrodynamic models without critical dynamics.

    hep-phhep-latnucl-exnucl-thPRL(2025)·14 citations
15. 15*

    Constraints on dark matter boosted by supernova shock within the effective field theory framework from the CDEX-10 experiment

    J. Z. Wang · L. T. Yang · Q. Yue · K. J. Kang · Y. J. Li · H. P. An · Greeshma C. · J. P. Chang · H. Chen · Y. H. Chen · J. P. Cheng · W. H. Dai and 75 other authors

    Supernova shocks can boost dark matter (DM) particles to high, yet nonrelativistic, velocities, providing a suitable mechanism for analysis within the framework of the nonrelativistic effective field theory (NREFT). These accelerated DM sources extend the experimental ability to scan the parameter space of light DM into the sub-GeV region. In this study, we specifically analyze DM accelerated by the Monogem Ring supernova remnant, whose age ($\sim 68000$ yr) and distance to Earth ($\sim 300$ parsec) are strategically matched to enable detection with current terrestrial detectors. Utilizing the 205.4 kg$\cdot$day data obtained from the CDEX-10 experiment at the China Jinping Underground Laboratory, we derive new constraints on boosted DM within the NREFT framework. The NREFT coupling constant exclusion regions now penetrate the sub-GeV mass range, with optimal sensitivity achieved for operators ${\mathcal{O}}_3$, ${\mathcal{O}}_6$, ${\mathcal{O}}_{15}$ in the 0.4--0.6 GeV mass range.

    hep-phhep-exphysics.ins-detPRD(2025)·2 citations
16. 16*

    Color superconductivity under neutron-star conditions at next-to-leading order

    Andreas Geißel🇩🇪 · Tyler Gorda🇩🇪 · Jens Braun🇩🇪

    The equation of state of deconfined strongly interacting matter at high densities remains an open question, with effects from quark pairing in the preferred color-flavor-locked (CFL) ground state possibly playing an important role. Recent studies suggest that at least large pairing gaps in the CFL phase are incompatible with current astrophysical observations of neutron stars. At the same time, it has recently been shown that in two-flavor quark matter, subleading corrections from pairing effects can be much larger than would be naïvely expected, even for comparatively small gaps. In the present Letter, we compute next-to-leading-order corrections to the pressure of quark matter in the CFL phase arising from the gap and the strong coupling constant, incorporating neutron-star equilibrium conditions and current state-of-the-art perturbative QCD results. We find that the corrections are again quite sizable, and they allow us to constrain the CFL gap in the quark energy spectrum to ${\Delta }_{\mathrm{CFL}}\lesssim 140\mathrm{MeV}$ at a baryon chemical potential ${\mu }_{\mathrm{B}}=2.6\mathrm{GeV}$, even when allowing for a wide range of possible behaviors for the dependence of the gap on the chemical potential.

    hep-phnucl-thPRL(2025)·23 citations
17. 17*

    Exploring Leptogenesis in the Era of First Order Electroweak Phase Transition

    Dipendu Bhandari🇮🇳 · Arunansu Sil🇮🇳

    We present a novel approach for implementing baryogenesis via leptogenesis at low scale within neutrino seesaw framework where a sufficient lepton asymmetry can be generated via out of equilibrium CP-violating decays of right handed neutrinos (RHNs) even when their mass falls below the Standard Model (SM) Higgs mass. It becomes possible by keeping the sphaleron in equilibrium below its conventional decoupling temperature $T_{\mathrm{sp}}^{\mathrm{SM}}\sim 131.7$ GeV in SM so as to facilitate the conversion of lepton asymmetry to baryon asymmetry at such a low scale, thanks to the flexibility of the bubble nucleation temperature in case the electroweak phase transition (EWPT) is of first order. The scenario emerges as an exciting (and perhaps unique) possibility for low scale leptogenesis, particularly if the Universe attains a reheating temperature lower than 131.7 GeV. We show that a stochastic gravitational wave, characteristic of such first order EWPT, may be detected in near future detectors while the presence of RHNs of mass as low as 35 GeV opens up an intriguing detection possibility at current and future accelerator experiments.

    hep-phastro-ph.COhep-thPRD(2026)·5 citations
18. 18*

    Quantum properties of $H\to V{V}^{\ast }$: precise predictions in the SM and sensitivity to new physics

    Morgan Del Gratta🇮🇹 · Federica Fabbri🇮🇹 · Priyanka Lamba🇮🇹 · Fabio Maltoni🇧🇪 · Davide Pagani🇮🇹

    We study the quantum properties of the Higgs-boson decays into four fermions via two vector bosons $(H\to V{V}^{\ast }\to 4f)$. In particular, we focus on the case of two different-flavour lepton pairs $(H\to Z{Z}^{\ast }\to {\mu }^{+}{\mu }^{-}{e}^{+}{e}^{-})$. We compute the quantum-information observables for the corresponding two-qutrit system $(ZZ)$ at next-to-leading order electroweak (NLO EW) accuracy in the SM. We find that NLO EW corrections lead to giant (order 1) effects in some specific cases, significantly altering the extraction of observables quantifying the quantum correlations. We identify observables that are robust and can be used to extract reliable information. Finally, we discuss possible new physics (NP) effects, parametrised via an effective-field-theory approach. We show how quantum observables can increase the sensitivity to NP also for the process considered in this study.

    hep-phhep-exquant-phJHEP(2025)·42 citations
19. 19*

    Multiscale Cosmic Curvature: from Local Structures to Cosmology

    David Benisty🇩🇪

    This study tackles the impact Dark Energy (DE) in different systems by a simple unifying formalism. We introduce a parameter space that compare gravity across all cosmic scales, using the McVittie spacetime (McV) and connects spherically symmetric solutions with cosmological solutions. By analyzing the invariant scalars: the Ricci, Weyl, and Kretschmann scalars, we develop a phase-space description that predicts the dominance of the Cosmological Constant. We explore three cases: (1) the local Hubble flow around galaxy groups and clusters, (2) spherical density distributions and (3) binary motion. Our results show that the Kretschmann scalar of galaxy groups and clusters in their turnaround is $2{\Lambda }^2$ which is three times the Kretschmann scalar of the Cosmological Consonant. This quantifies the DE domination in local structures.

    ↳ gr-qcastro-ph.COastro-ph.GAhep-phPRD(2025)·6 citations
20. 20*

    Input to European Strategy Update for Particle Physics: Sustainability

    Veronique Boisvert🇬🇧 · Daniel Britzger🇩🇪 · Samuel Calvet🇫🇷 · Yann Coadou🇫🇷 · Caterina Doglioni🇬🇧 · Julien Faivre🇫🇷 · Patrick Koppenburg🇳🇱 · Valerie S. Lang🇩🇪 · Kristin Lohwasser🇬🇧 · Zach Marshall🇺🇸 · Rakhi Mahbubani🇭🇷 · Peter Millington🇬🇧 and 5 other authors

    Human activity continues to have an enormous negative impact on the ability of the planet to sustain human and other forms of life. Six out of the nine planetary boundaries have been crossed, a seventh is close to threshold. Prominent manifestations of this development are climate change caused by greenhouse gas emissions, as well as loss of biodiversity. In recognition of the urgency of these problems, several international agreements have been ratified to achieve net-zero emissions and to halt and reverse biodiversity loss. Significant reductions in emissions are required by 2030 to meet international climate targets. The field of particle physics has an obligation and an opportunity to contribute to such mitigation efforts and to avoid causing further harm. This document urges the European Strategy Update in Particle Physics to set a clear and bold mandate for embedding environmental sustainability throughout the future scientific programme, and advocates for a series of actions that will enable this.

    ↳ physics.soc-phhep-exhep-phhep-th3 citations
21. 21*

    2026 ESPPU input from the ANUBIS Collaboration

    Oleg Brandt🇬🇧 · Paul Swallow (for the ANUBIS Collaboration)🇬🇧

    It is imperative for us as a particle physics community to fully exploit the physics potential of the High-Luminosity LHC. This calls for us not to leave any stone unturned in the search for Beyond the Standard Model (BSM) physics. Many BSM models that address fundamental questions of physics like the particulate nature of dark matter, the matter-antimatter asymmetry in the Universe, small but non-zero neutrino masses etc, predict Long-Lived Particles (LLPs) with macroscopic lifetimes of $\tau >10^{-10}$ s. The challenge in searching for BSM models with LLP signatures at the HL-LHC is that it requires the complementary interplay of general purpose detectors like ATLAS, CMS, and LHCb; dedicated detectors situated close to the beamline including the proposed Forward Physics Facility (FPF); and dedicated detectors covering a large decay volume at a reasonable solid angle transverse to the beamline, i.e., a Transverse Physics Facility (TPF). Hence, it is of vital importance to realise a TPF in order to expand dramatically the physics coverage within long-lived particle searches to harvest the physics at the HL-LHC fully. A TPF may be composed of several experiments based at the HL-LHC. In this document, we propose that the community realise the ANUBIS experiment as part of a TPF.

    ↳ hep-exhep-ph6 citations
22. 22*

    Inclusive semileptonic decays from lattice QCD: analysis of systematic effects

    Ryan Kellermann🇯🇵 · Alessandro Barone🇩🇪 · Ahmed Elgaziari🇬🇧 · Shoji Hashimoto🇯🇵 · Zhi Hu🇯🇵 · Andreas Jüttner🇬🇧 · Takashi Kaneko🇯🇵

    Lattice QCD calculations of inclusive semileptonic decay rates involve new types of systematic effects, such as truncation errors in the estimation of energy integrals, or finite-volume effects for multi-body final states. We investigate them for the lattice data of $D_s\to X_s\ell \nu$ decays, obtained using Möbius domain-wall fermions. Separating the ground-state and excited-state contributions results in better control over these systematic effects. With the Chebyshev polynomial approximation, the truncation error is under control, while the finite-volume effects are estimated using a model to describe two-body final states.

    ↳ hep-lathep-phPRD(2025)·21 citations
23. 23*

    Tunneling with physics-informed RG flows in the anharmonic oscillator

    Alfio Bonanno🇮🇹 · Friederike Ihssen🇩🇪 · Jan M. Pawlowski🇩🇪

    We solve the anharmonic oscillator with physics-informed renormalisation group (PIRG) flows, with an emphasis on the weak coupling regime with its instanton-dominated tunnelling processes. We show that the instanton physics behind the exponential decay of the energy gap is already covered in the first order of the derivative expansion of the PIRG. The crucial new ingredients in the present analysis are the use of the ground state expansion within PIRG flows, as well as precision numerics based on Galerkin methods. Our result $a_{\mathrm{inst}}=1.910(2)$ for the decay constant is in quantitative agreement with the analytic one, $a_{\mathrm{inst}}=1.886$ with a deviation of $1\%$. This illustrates very impressively the capacity of the PIRG for fully capturing non-perturbative physics already in relatively simple approximations.

    ↳ hep-thhep-phSciPost Phys.Core(2026)·7 citations
24. 24*

    Doubly heavy tetraquarks from lattice QCD: incorporating diquark-antidiquark operators and the left-hand cut

    S. Prelovsek🇸🇮 · E. Ortiz-Pacheco🇸🇮 · S. Collins🇩🇪 · L. Leskovec🇸🇮 · M. Padmanath🇮🇳 · I. Vujmilovic🇸🇮

    Lattice studies of the doubly-charm tetraquark $T_{cc}=cc\bar{u}\bar{d}$ require the determination of the $D{D}^{\ast }$ scattering amplitude, which most often incorporate only meson-meson interpolators. We additionally incorporate diquark-antidiquark operators and find that these have some impact on certain eigenenergies. This study presents the first extraction of the $D{D}^{\ast }$ scattering amplitude based on the meson-meson as well as diquark antidiquark interpolators. The effect of the additional operators renders slightly smaller values of $p\cot {\delta }_0$ and a $T_{cc}$ pole slightly closer to the threshold. The scattering amplitude is extracted from eigenenergies by adopting plane-wave and effective-field-theoretic methods, which also incorporate the left-hand cut and address the partial wave mixing. The $T_{cc}$ is found to be a subthreshold resonance with a pole at $m_{T_{cc}}-m_D-m_{D^{\ast }}=-5.2_{-0.8}^{+0.7}-i\cdot 6.3_{-4.8}^{+2.4}$MeV, employing CLS ensembles with $m_{\pi }\simeq 280$MeV and the distillation method. A more significant effect of diquark-antidiquark operators on eigen-energies is found for larger heavy quark masses relevant for $T_{bb}$. We find that deeply bound $T_{bb}$ does not emerge when employing only meson-meson operators, where each meson is separately momentum projected, while the deeply bound state emerges after adding local diquark antidiquark operators.

    ↳ hep-lathep-phPRD(2025)·32 citations
25. 25*

    Quenching through the QCD chiral phase transition

    Adrien Florio🇩🇪 · Eduardo Grossi🇮🇹 · Aleksas Mazeliauskas🇩🇪 · Alexander Soloviev🇸🇮 · Derek Teaney🇺🇸

    We present a detailed numerical and analytical study of the out-of-equilibrium dynamics of Model G, the dynamical universality class relevant to the chiral phase transition. We perform numerical 3D stochastic (Langevin) simulations of the $O(4)$ critical point for large lattices in the chiral limit. We quench the system from the high-temperature unbroken phase to the broken phase and study the non-equilibrium dynamics of pion fields. Strikingly, the non-equilibrium evolution of the two-point functions exhibits a regime of growth, a parametrically large enhancement, and a subsequent slow relaxation to equilibrium. We analyze our numerical results using dynamic critical scaling and mean-field theory. The growth of the two point functions is determined by the non-linear dynamics of an ideal non-abelian superfluid, which is a limit of Model G that reflects the broken chiral symmetry. We also relate the non-equilibrium two-point functions to a long-lived parametric enhancement of soft pion yields relative to thermal equilibrium following a quench.

    ↳ hep-lathep-phnucl-thPRD(2025)·9 citations
26. 26*

    Observation of Temperature Effects on False Vacuum Decay in Atomic Quantum Gases

    Riccardo Cominotti (1)🇮🇹 · Cosetta Baroni (1,2)🇮🇹 · Chiara Rogora (1)🇮🇹 · Diego Andreoni (1)🇮🇹 · Giacomo Guarda (1)🇮🇹 · Giacomo Lamporesi (1)🇮🇹 · Gabriele Ferrari (1)🇮🇹 · Alessandro Zenesini (1) ((1) Pitaevskii BEC Center, CNR-INO and Dipartimento di Fisica, Universita' di Trento, Trento, Italy, and Trento Institute for Fundamental Physics and Applications, INFN, Trento, Italy (2) Institute for Quantum Optics and Quantum Information (IQOQI) and Institute for Experimental Physics, University of Innsbruck, Innsbruck, Austria)🇮🇹

    Temperature plays a crucial role in metastable phenomena, not only by contributing to determine the state (phase) of a system, but also ruling the decay probability to more stable states. Such a situation is encountered in many different physical systems, ranging from chemical reactions to magnetic structures. The characteristic decay timescale is not always straightforward to estimate since it depends on the microscopic details of the system. A paradigmatic example in quantum field theories is the decay of the false vacuum, manifested via the nucleation of bubbles. In this paper, we measure the temperature dependence of the timescale for the false vacuum decay mechanism in an ultracold atomic quantum spin mixture which exhibits ferromagnetic properties. Our results show that the false vacuum decay rate scales with temperature as predicted by the finite-temperature extension of the instanton theory, and confirm atomic systems as an ideal platform where to study out-of-equilibrium field theories.

    ↳ cond-mat.quant-gascond-mat.stat-mechhep-phhep-th+1PRL(2025)·14 citations
27. 27*

    The Spectrum of Gravitational Waves from Annihilating Domain Walls

    Alessio Notari🇪🇸 · Fabrizio Rompineve🇪🇸 · Francisco Torrenti🇪🇸

    Networks of cosmic domain walls can form in the early Universe as a consequence of the spontaneous breaking of discrete symmetries. We study the production of a cosmological background of gravitational waves (GWs) from such networks, when they annihilate due to a small explicit symmetry breaking term. Averaging over several 3+1-dimensional high-resolution lattice field simulations, we obtain a GW spectrum with the following characteristics: (1) a broad asymmetric peak, roughly located at frequency (at the time of emission) $f\sim 2H_{\mathrm{gw}}$, where $H_{\mathrm{gw}}$ is the Hubble rate at the end of GW production, shortly after annihilation, (2) a doubly broken power law spectrum $\propto k^{-n}$, with initial slope $n\sim 0.5$ after the main peak and $n\sim 1.8$ at high $f$, while the low frequency region $f<f_p$ agrees with the causality behavior $\sim k^3$. Additionally, extending previous results, we find that GW production continues to be efficient until a value of the Hubble scale $H_{\text{g}w}$ that is roughly an order of magnitude smaller than the naive estimate $\sigma H=\Delta V$, where $\sigma$ is the wall tension and $\Delta V$ the size of the symmetry breaking term, thereby leading to a $O(100)$ larger GW signal. We find such results to be robust when changing the shape of the scalar field potential or including a time-dependent symmetry breaking term. Our findings have important implications for GW searches, especially in light of the reported evidence for a stochastic GW background in Pulsar Timing Array data.

    ↳ astro-ph.COhep-phJCAP(2025)·32 citations
28. 28*

    The ISW-Lensing Bispectrum & Trispectrum

    Oliver H. E. Philcox🇺🇸 · J. Colin Hill🇺🇸

    Due to the integrated Sachs-Wolfe (ISW) effect, cosmic microwave background (CMB) temperature and polarization fluctuations are correlated with the gravitational lensing potential. Famously, this induces a CMB three-point function, whose shape can be used to constrain dark energy and modifications to gravity. An analogous effect occurs at higher-order, producing an ISW-lensing trispectrum whose amplitude is hitherto unconstrained. We present a detailed discussion of this effect, and define minimum-variance estimators for the ISW-lensing three- and four-point functions. These are implemented within the PolySpec code, and bear strong similarities to the quadratic estimators used in lensing analyses. Applying these tools to Planck, we obtain strong detections of the bispectrum amplitude (consistent with previous works), but find only weak constraints on the trispectrum, due to a strong cancellation between the various ISW-induced contributions. We additionally forecast the constraints from future datasets, finding that (a) simple estimators for the ISW-lensing bispectrum will be severely limited by non-Gaussian modifications to the covariance, and (b) the ISW-lensing trispectrum will be very challenging to detect even with high-resolution future experiments. We finally consider the induced bias on primordial non-Gaussianity amplitudes (and lensing itself), which we show to be large for the bispectrum (as expected) but negligible for the trispectrum.

    ↳ astro-ph.COastro-ph.GAgr-qchep-ph+18 citations
29. 29*

    High-energy gamma-ray emission from memory-burdened primordial black holes

    Marco Chianese🇮🇹

    Theoretical studies on the memory-burden effect suggest that Primordial Black Holes (PBHs) with masses smaller than $10^{15}$ grams may be viable dark matter candidates and, consequently, be potential sources of high-energy particles in the present Universe. In this paper, we investigate the evaporation of memory-burdened PBHs into high-energy gamma-rays. Differently from previous analyses, we account for the attenuation of gamma-rays caused by their interaction with background radiation at energies above $10^5\mathrm{GeV}$, as well as the secondary emission from the electromagnetic cascades generated during their propagation through extragalactic space. Performing a likelihood analysis with current gamma-ray data, we place new constraints on the parameter space of memory-burdened PBHs. Our results show that ultra-high-energy diffuse gamma-ray observations set more restrictive bounds than high-energy neutrino data, particularly in scenarios with a strong memory-burden suppression of the PBH evaporation.

    ↳ astro-ph.HEastro-ph.COhep-phPRD(2025)·25 citations
30. 30*

    Simple third order operator-splitting schemes for stochastic mechanics and field theory

    Andrey Shkerin🇨🇦 · Sergey Sibiryakov🇨🇦

    We present a method for constructing numerical schemes with up to 3rd strong convergence order for solution of a class of stochastic differential equations, including equations of the Langevin type. The construction proceeds in two stages. In the first stage one approximates the stochastic equation by a differential equation with smooth coefficients randomly sampled at each time step. In the second stage the resulting regular equation is solved with the conventional operator-splitting techniques. This separation renders the approach flexible, allowing one to freely combine the numerical techniques most suitable to the problem at hand. The approach applies to ordinary and partial stochastic differential equations. In the latter case, it naturally gives rise to pseudo-spectral algorithms. We numerically test the strong convergence of several schemes obtained with this method in mechanical examples. Application to partial differential equations is illustrated by real-time simulations of a scalar field with quartic self-interaction coupled to a heat bath. The simulations accurately reproduce the thermodynamic properties of the field and are used to explore dynamics of thermal false vacuum decay in the case of negative quartic coupling.

    ↳ hep-latastro-ph.COcond-mat.stat-mechhep-ph+1Comput.Phys.Commun.(2026)·2 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.