Fri·May 16, 2025Friday·May 16, 2025

1. 01*

   Violation of energy conditions and the gravitational radius of the proton

   Adrian Dumitru🇺🇸 · Jorge Noronha🇺🇸

   The energy-momentum tensor (EMT) of the proton encodes fundamental information about its mass, pressure, and shear distributions. Using recent lattice QCD data for the gravitational form factors, we show that the Breit-frame Wigner EMT may be of Hawking-Ellis type IV in the proton's core. Such EMT violates all pointwise energy conditions and lacks a causal rest frame so that the usual mechanical picture fails at short distances. We define the gravitational radius -- a new hadronic observable marking the scale where the EMT becomes ordinary (type I) and the classical interpretation is restored. We also derive from the Averaged Null Energy Condition (ANEC) non-perturbative, model-independent QFT constraints on gravitational form factors.

   hep-phPRD(2025)·3 citations
2. 02*

   Aspects of the WIMP quality problem and R-parity violation in natural supersymmetry with all axion dark matter

   Howard Baer🇺🇸 · Vernon Barger🇺🇸 · Jessica Bolich🇺🇸 · Dibyashree Sengupta🇮🇹 · Kairui Zhang🇺🇸

   In supersymmetric models where the mu problem is solved via discrete R-symmetries, then both the global U(1)_{PQ} (Peccei-Quinn, needed to solve the strong CP problem) and R-parity conservation (RPC, needed for proton stability) are expected to arise as accidental, approximate symmetries. Then in some cases, SUSY dark matter is expected to be all axions since the relic lightest SUSY particles (LSPs) can decay away via small R-parity violating (RPV) couplings. We examine several aspects of this {\it all axion} SUSY dark matter scenario. 1. We catalogue the operator suppression which is gained from discrete R-symmetry breaking via four two-extra-field base models. 2. We present exact tree-level LSP decay rates including mixing and phase space effects and compare to results from simple, approximate formulae. 3. Natural SUSY models are characterized by light higgsinos with mass ~100-350 GeV so that the dominant sparticle production cross sections at LHC14 are expected to be higgsino pair production which occurs at the 10^2-10^4 fb level. Assuming nature is natural, the lack of an RPV signal from higgsino pair production in LHC data translates into rather strong upper bounds on nearly all trilinear RPV couplings in order to render the SUSY signal (nearly) invisible. Thus, in natural SUSY models with light higgsinos, the RPV-couplings must be small enough that the LSP has a rather high quality of RPC.

   hep-phhep-thJCAP(2025)·12 citations
3. 03*

   Quantization Rules in Holographic QCD Models

   Luiz F. Ferreira🇨🇱 · Alfredo Vega🇨🇱

   In this paper, we investigate quasinormal modes in holographic QCD models from the perspective of the WKB approximation. We derive the generalized Bohr Sommerfeld quantization rules for quasi-stationary states in holographic QCD models. As a simple application of these formulas, we compute the quasinormal modes of scalar and vector fields in the soft wall model, where an analytic expression for the real part of the frequency can be found in the low temperature regime. Additionally, this study provides useful insights into the dissociation process in holographic QCD models.

   hep-phhep-thPRD(2025)·1 citation
4. 04*

   Observation of quantum entanglement in $\Lambda \bar{\Lambda }$ pair production via electron-positron annihilation

   Junle Pei🇨🇳 · Xiqing Hao🇨🇳 · Xiaochuan Wang🇨🇳 · Tianjun Li🇨🇳

   We report the observation of quantum entanglement in $\Lambda \bar{\Lambda }$ pairs produced via electron-positron annihilation, specifically through the decay $J/\psi \to \Lambda \bar{\Lambda }$. By analyzing the angular correlations of the subsequent weak decays $\Lambda \to p{\pi }^{-}$ and $\bar{\Lambda }\to \bar{p}{\pi }^{+}$, we derive normalized observables ${\mathcal{O}}_i(i=0,1,\dots ,4)$ that distinguish entangled states from separable ones. Theoretical predictions for these observables are established, with violations of separable-state bounds serving as unambiguous signatures of entanglement. Experimental measurements at $\cos {\theta }_{\Lambda }=0$ yield ${\mathcal{O}}_{1\text{min}}^{\text{Observed}}=-0.7374\pm 0.0011\pm 0.0016$, significantly exceeding the classical limit of $-0.5$ with a statistical significance of 124.9$\sigma$. For $\left|\cos {\theta }_{\Lambda }\right|<0.4883$, the observed ${\mathcal{O}}_1^{\text{Observed}}$ consistently exhibits ${\mathcal{O}}_1^{\text{Observed}}<-\frac{1}{2}$ with a statistical significance of at least 5$\sigma$. Since $69.3\%$ of the decay events involving $\Lambda \to p+{\pi }^{-}$ and $\bar{\Lambda }\to \bar{p}+{\pi }^{+}$ are spacelike-separated, our results confirming the persistence of quantum entanglement in the $\Lambda \bar{\Lambda }$ system provide strong support for the non-locality of quantum mechanics. The findings are consistent with theoretical expectations under decoherence-free conditions, highlighting the potential of hyperon pairs as probes for fundamental quantum phenomena.

   hep-ph18 citations
5. 05*

   Scale Factorized-Quantum Field Theory: Eliminating renormalization ambiguities in QCD and QED

   Farrukh A. Chishtie🇨🇦

   We introduce Scale Factorized-Quantum Field Theory (SF-QFT), a framework performing path-integral factorization of ultraviolet and infrared momentum modes at a physical scale $Q^{\ast }$ before perturbative expansion through Effective Dynamical Renormalization (EDR) with Principle of Observable Effective Matching (POEM) constraints. This yields completely scale and scheme invariant observables. Because the two-loop $\beta$-function is universal, $a_{\mathrm{eff}}(Q)$ evolves with scheme-independent equations, with higher-order $\beta$-coefficients absorbed into Wilson coefficients. For the inclusive ratio $R_{e^{+}{e}^{-}}$, SF-QFT gives $R^{\mathrm{SF}-\mathrm{QFT}}(31.6\mathrm{GeV})=1.05262\pm 0.0005$, in excellent agreement with experiment ($1.0527\pm 0.005$) while requiring calculations orders of magnitude simpler than conventional four-loop $\overline{\mathrm{MS}}$ approaches. SF-QFT generates universal algebraic recursion relations producing all higher-order contributions without additional Feynman diagrams. For QED, the formalism yields scheme-independent predictions for the electron anomalous magnetic moment with $a_e^{\text{theory}}=0.00115965218061(76)$, differing from experiment by only $0.15\sigma$. The framework enables self-consistent extraction of ${\alpha }_{\text{eff}}^{-1}(m_e)=137.036005301$. SF-QFT represents a paradigm shift, replacing pursuit of ever-higher loop orders with a unified framework eliminating renormalization ambiguities through systematic EDR and POEM implementation.

   hep-phgr-qchep-exhep-lat+1PTEP(2026)·1 citation
6. 06*

   Sphalerogenesis

   Masanori Tanaka🇨🇳

   We propose a mechanism called sphalerogenesis to explain the baryon asymmetry of the universe (BAU). The BAU is explained by a CP-violating decay of the electroweak sphaleron. We introduce a dimension-six operator constructed from weak gauge fields: $Q_{\tilde{W}}\sim {\Lambda }^{-2}{ϵ}_{ijk}{\tilde{W}}_{\mu \nu }^i{W}^{j\nu \rho }{W}_{\rho }^{k\mu }$. We find that the BAU can be explained if $\Lambda \simeq 38\mathrm{TeV}$. This scenario can be tested by electron electric dipole moment measurements in the near future.

   hep-phhep-exPRD(2026)·4 citations
7. 07*

   Light Axion-Like Particles at Future Lepton Colliders

   Shou-shan Bao🇨🇳 · Yang Ma🇧🇪 · Yongcheng Wu🇨🇳 · Keping Xie🇺🇸 · Hong Zhang🇨🇳

   Axion-like particles (ALPs) are well-motivated extensions of the Standard Model (SM) that appear in many new physics scenarios, with masses spanning a broad range. In this work, we systematically study the production and detection prospects of light ALPs at future lepton colliders, including electron-positron and multi-TeV muon colliders. At lepton colliders, light ALPs can be produced in association with a photon or a $Z$ boson. For very light ALPs ($m_a<1$ MeV), the ALPs are typically long-lived and escape detection, leading to a mono-$V$ ($V=\gamma ,Z$) signature. In the long-lived limit, we find that the mono-photon channel at the Tera-$Z$ stage of future electron-positron colliders provides the strongest constraints on ALP couplings to SM gauge bosons, $g_{aVV}$, thanks to the high luminosity, low background, and resonant enhancement from on-shell $Z$ bosons. At higher energies, the mono-photon cross section becomes nearly energy-independent, and the sensitivity is governed by luminosity and background. At multi-TeV muon colliders, the mono-$Z$ channel can yield complementary constraints. For heavier ALPs ($m_a>100$ MeV) that decay promptly, mono-$V$ signatures are no longer valid. In this case, ALPs can be probed via non-resonant vector boson scattering (VBS) processes, where the ALP is exchanged off-shell, leading to kinematic deviations from SM expectations. We analyze constraints from both light-by-light scattering and electroweak VBS, the latter only accessible at TeV-scale colliders. While generally weaker, these constraints are robust and model-independent. Our combined analysis shows that mono-$V$ and non-resonant VBS channels provide powerful and complementary probes of ALP-gauge boson interactions.

   hep-phhep-exJHEP(2025)·14 citations
8. 08*

   Multi-component Dark Matter from an $SU(2{)}_D\to Z_3^D\times Z_2^{\text{acc}}$ scenario

   Carlos Alvarado🇺🇸 · Alfredo Aranda🇲🇽 · Cesar Bonilla🇨🇱 · Carlos Ramos Portalatino🇵🇪

   A multi-component weakly-interacting dark matter scenario is analyzed, where the candidate dark matter states arise from the $SU(2{)}_D\to Z_3^D\times Z_2^{\text{acc}}$ symmetry breaking triggered by a VEV-developing scalar in the $J=3/2$ representation. While the discrete symmetries guarantee at least two stable states, a closer look at the mass orderings of the contrived dark sector reveals the existence of a third dark matter candidate, whose stability effectively results from the tight phase space in the dark boson sector. Regions of masses and couplings where the three dark states furnish a comparable contribution to the observed relic abundance are determined numerically.

   hep-phPRD(2025)·0 citations
9. 09*

   Electromagnetic and weak decay of singly Heavy Baryons (Qqq)

   Kinjal Patel🇮🇳 · Kaushal Thakkar🇮🇳

   The heavy-to-heavy exclusive semileptonic transitions of singly heavy baryons (SHBs) are investigated within the framework of the Hypercentral Constituent Quark Model (hCQM). The six-dimensional hyperradial Schrödinger equation is solved in the variational approach to calculate the ground state masses of bottom and charmed baryons. The transition magnetic moments and radiative $M1$ decay widths are calculated using the spin-flavour wave function and the effective quark masses of constituent baryon. The Isgur-Wise function (IWF) is determined at zero recoil to compute the $b\to c$ semileptonic decay. Additionally, the branching ratios, as well as the slope and convexity parameters of IWF are evaluated and compared with results from other studies.

   hep-phEur.Phys.J.Plus(2025)·5 citations
10. 10*

    Quest for a phenomenologically consistent low cutoff theory

    Sudhakantha Girmohanta🇨🇳 · Yu-Cheng Qiu🇨🇳

    The Randall-Sundrum model with the Higgs localized on the IR brane solves the gauge hierarchy problem. However, the associated low cutoff ($\Lambda \sim 10$ TeV) generically leads to unacceptably rapid nucleon decay and excessively large Majorana neutrino masses. Achieving consistency while simultaneously explaining the Yukawa hierarchy requires either a horizontal symmetry or a discrete gauged symmetry. We demonstrate that eliminating all dangerous operators within a horizontal symmetry framework must come with large and unattractive charge assignments, if possible at all. Hence, we consider an exact discrete gauged ${\mathbf{Z}}_N$ symmetry, with fermion mass hierarchies generated via wave function overlap. We employ this to reproduce the current Cabibbo-Kobayashi-Maskawa and Pontecorvo-Maki-Nakagawa-Sakata structures. Assuming universal five-dimensional Yukawa couplings, generation-blind profile for right-handed neutrinos and flat profile for the third generation SM doublets, it predicts Dirac neutrinos with a total mass $\sim 66$ meV. Since the ${\mathbf{Z}}_N$ charges must be generation blind, flavor observables serve as key probes.

    hep-phhep-thPRD(2025)·1 citation
11. 11*

    Dark Photon Searches with Initial-State Radiation at Fixed-Target Configurations

    Shao-Feng Ge🇨🇳 · Jinhan Liang🇨🇳 · Zuowei Liu🇨🇳 · Ui Min🇨🇳

    In this work, we investigate the contribution of the annihilation process with initial-state radiation ($e^{+}{e}^{-}\to \gamma A^{\prime }$) to the invisible dark photon ($A^{\prime }$) searches at the electron fixed-target configurations. For illustration, we consider both the disappearing positron track signature at Belle II and the large missing energy search at NA64. When the dark photon has a narrow decay width, the effect of the initial-state radiation to the annihilation process can dominate over its $s$-channel and bremsstrahlung counterparts around $m_{A^{\prime }}\simeq 60\mathrm{MeV}$ ($m_{A^{\prime }}\simeq 200\mathrm{MeV}$) for Belle II (NA64), to enhance the corresponding sensitivity on the kinetic mixing parameter $ϵ$ by a factor of up to approximately 2.7 (1.3). For Belle II, we further perform a multi-bin analysis with the spectrum information to better separate the background and signal channels for significant improvement of the sensitivity.

    hep-ph4 citations
12. 12*

    Electromagnetic properties of possible triple-charm molecular hexaquarks

    Chen-Ke Zhang🇨🇳 · Fu-Lai Wang🇨🇳 · Si-Qiang Luo🇨🇳 · Xiang Liu🇨🇳

    In this study, we investigate the radiative transitions of predicted triple-charm molecular hexaquarks, which play a significant role in understanding their overall spectroscopic properties. As experimentally measurable quantities, the radiative decay widths provide insights into the internal structures of these triple-charm molecular hexaquarks. Additionally, we calculate their corresponding magnetic moments, which, together with the radiative decay widths, offer a comprehensive picture of the electromagnetic properties of these exotic states. This information is valuable for guiding future experimental searches and advancing our understanding of these unique hadronic systems.

    hep-phhep-exEPJC(2025)·5 citations
13. 13*

    Window quantities for the hadronic vacuum polarization contributions to the muon anomalous magnetic moment in spacelike and timelike domains

    A.V.Nesterenko🇷🇺

    The relations between the window quantities for the hadronic vacuum polarization contributions to the muon anomalous magnetic moment $a_{\mu }^{\text{HVP}}$ in spacelike and timelike domains are studied. Two types of window functions (abrupt and smooth) as well as two kinds of kinematic intervals (symmetric and asymmetric with respect to the spacelike/timelike flip) are addressed. It is shown that the window quantities for $a_{\mu }^{\text{HVP}}$ represented in terms of the hadronic vacuum polarization function $\bar{\Pi }(Q^2)$, the Adler function $D(Q^2)$, and the $R$-ratio of electron-positron annihilation into hadrons are mutually equivalent only if the additional contributions due to the window edge effects are properly taken into account and the explicit expressions for such contributions are derived. The obtained results enable one to evaluate $a_{\mu }^{\text{HVP}}$ by making simultaneous use of the inputs for functions $\bar{\Pi }(Q^2)$, $D(Q^2)$, and $R(s)$ at various energies and an example of such hybrid assessment is provided. The obtained results also enable one to accurately compare the window quantities for $a_{\mu }^{\text{HVP}}$ based, e.g., on MUonE or lattice data with the ones based on $R$-ratio data, even if the window function covers different kinematic ranges in spacelike and timelike domains.

    hep-phhep-latJ.Phys.G(2026)·0 citations
14. 14*

    Towards N${}^3$LO PDFs and their implications for Higgs production cross-sections

    Felix Hekhorn🇫🇮

    We review the recently published PDF sets MSHT20xNNPDF40_an3lo and MSHT20xNNPDF40_an3lo_qed, which have been obtained by combining the approximate N${}^3$LO (aN${}^3$LO) sets of parton distributions (PDFs) from the MSHT20 and NNPDF4.0 series. We investigate the impact of the most recent results on N${}^3$LO splitting functions onto the two PDF sets. Finally, we demonstrate the impact of N${}^3$LO PDFs on the computation of Higgs production cross-sections at the LHC.

    hep-ph1 citation
15. 15*

    Invariant-mass threshold resummation for the production of four top quarks at the LHC

    Melissa van Beekveld🇳🇱 · Anna Kulesza🇩🇪 · Michele Lupattelli🇩🇪 · Tommaso Saracco🇳🇱

    Using invariant-mass threshold resummation, we compute the invariant-mass distribution and the total cross section for $t\bar{t}t\bar{t}$ production at the LHC with centre-of-mass energy of 13.6 TeV at NLL' accuracy. This accuracy includes next-to-leading logarithmic contributions together with relative $\mathcal{O}({\alpha }_s)$ non-logarithmic terms present in the threshold limit. We match the NLL' results to NLO in QCD and to complete NLO with electroweak corrections. We find that the inclusion of NLL' soft-gluon corrections significantly reduces the size of the theoretical uncertainties and greatly improves the convergence of the predictions when considering various choices of renormalisation and factorisation scales.

    hep-phJHEP(2025)·7 citations
16. 16*

    One-loop amplitudes for $t\bar{t}j$ and $t\bar{t}\gamma$ productions at the LHC through $\mathcal{O}({ϵ}^2)$

    Souvik Bera🇰🇷 · Colomba Brancaccio🇮🇹 · Dhimiter Canko🇮🇹 · Heribertus Bayu Hartanto🇰🇷

    We present analytic expressions for the one-loop QCD helicity amplitudes contributing to top-quark pair production in association with a photon or a jet at the Large Hadron Collider (LHC), evaluated through $\mathcal{O}({ϵ}^2)$ in the dimensional regularisation parameter, $ϵ$. These amplitudes are required to construct the two-loop hard functions that enter the NNLO QCD computation. The helicity amplitudes are expressed as linear combinations of algebraically independent components of the $ϵ$-expanded master integrals--known as pentagon function--with the corresponding rational coefficients written in terms of momentum-twistor variables. We derive differential equations for the pentagon functions and solve them numerically using the generalised power series expansion method.

    hep-phSciPost Phys.(2025)·4 citations
17. 17*

    QCD splitting functions beyond kinematical limits

    John M. Campbell🇺🇸 · Stefan Höche🇺🇸 · Max Knobbe🇺🇸 · Christian T. Preuss🇩🇪 · Daniel Reichelt🇨🇭

    We present a systematic decomposition of QCD splitting functions into scalar dipole radiators and pure splitting remainders up to second order in the strong coupling. The individual components contain terms that are formally sub-leading in soft or collinear scaling parameters, but well understood and universal due to their origin in scalar QCD. The multipole radiator functions which we derive share essential features of the known double-soft and one-loop soft gluon currents, and are not based on kinematical approximations.

    hep-phPRD(2026)·7 citations
18. 18*

    Double $\varphi$-meson production via $\bar{p}p$ scattering

    Dayoung Lee🇰🇷 · Seung-il Nam🇰🇷 · Jung Keun Ahn🇰🇷

    We investigate double $\varphi$ production in $\bar{p}p$ reactions near threshold using an effective Lagrangian approach, highlighting a significant OZI rule violation through hadronic processes. Our model includes $t$- and $u$-channel contributions from the nucleon and $s$-wave $N^{\ast }$ resonances ($N^{\ast }(1535,1650,1895)$), as well as the pentaquark-like state $P_s(2071)$. In the $s$-channel, scalar ($f_0$), tensor ($f_2$), and pseudoscalar ($\eta (2225)$) mesons are incorporated. The $N$, $N^{\ast }$, $f_0$, and $f_2$ contributions enhance the cross-section and generate peak structures near $W=2.2$ GeV, consistent with JETSET data, while cusp structures arise from $\bar{\Lambda }\Lambda$ and $\bar{\Sigma }\Sigma$ threshold openings. Polarization observables, such as the spin density matrix element (SDME), further elucidate the underlying hadronic mechanisms.

    hep-phPoS(2026)·0 citations
19. 19*

    Constraints on dark matter self-interaction from velocity distribution function in isolated halos

    Tirtha Sankar Ray🇮🇳 · Sambo Sarkar🇰🇷

    Self-interactions facilitate inter-particle redistribution of energy within the dense regions of galactic halos, implying modifications in the density and velocity distribution of dark matter. Simulating dark-matter only isolated halos for a wide range of mass and specific self-scattering cross-sections, we make a systematic study of the impact of self-scattering on the velocity distribution profiles. We report a conservative bound on $\sigma /m$ $\le 2.7\mathrm{c}{\mathrm{m}}^2/gm$ at $95\%$ C.L. from observations of rotation curves in Milky-Way size galaxies. Sub-leading bounds from LSB galaxy and clusters are also presented.

    hep-phastro-ph.GA1 citation
20. 20*

    $B\to D^{(\ast )}\tau {\nu }_{\tau }$ decay properties with RIQ model

    Sonali Patnaik🇮🇳 · Lopamudra Nayak🇮🇳 · Sanjay Kumar Swain🇮🇳

    In this work we compute the branching fraction of $B\to D^{(\ast )}\tau {\nu }_{\tau }$ and $B_s\to D_s^{(\ast )}\tau {\nu }_{\tau }$ within the Relativistic Independent Quark Model, emphasizing the harmonic potential model dependent analysis of these decay channels in the precision flavor physics era. Considering the experimental observation of longitudinal $\tau$-polarization and fraction of longitudinal polarization at LHCb and Belle, we have also investigated these observables within our model framework which are aligning well with the standard model expectations. We perform a comprehensive analysis of the form factors across the whole accessible kinematic range of $q^2$. Our results are consistent and compatible with other theoretical approaches as well as with the experimental measurements. Furthermore, we evaluated the clean ratios of $B_s$ to $B_0$ in the semimuonic mode that are in accordance with the LHCb measurements, and support the validity of the SU(3) flavor symmetry. Although the concept of new physics is facing a significant challenge at the current TeV scale, semileptonic $B$ decays, nevertheless, always serve as a valuable probe to study the decay dynamics.

    hep-ph0 citations
21. 21*

    Jet production at electron-positron colliders at next-to-next-to-next-to-leading order in QCD

    Xuan Chen🇨🇳 · Petr Jakubčík🇨🇭 · Matteo Marcoli🇬🇧 · Giovanni Stagnitto🇮🇹

    We present the first application of antenna subtraction at next-to-next-to-next-to-leading order (N${}^3$LO) in QCD by computing fully differential predictions for two-jet production at electron-positron colliders. We illustrate the structure of the infrared counterterms and provide results for the N${}^3$LO correction to the two-jet production rate and to the leading-jet energy. Our work constitutes the first direct calculation of jet production at electron-positron colliders at N${}^3$LO and represents the first step in tackling arbitrary processes with jets at this perturbative order.

    hep-phPLB(2025)·12 citations
22. 22*

    Fully Relativistic Treatment of Extreme Mass-Ratio Inspirals in Collisionless Environments

    Rodrigo Vicente🇳🇱 · Theophanes K. Karydas🇳🇱 · Gianfranco Bertone🇳🇱

    Future mHz gravitational wave (GW) interferometers will precisely probe massive black hole environments, such as accretion discs, cold dark matter overdensities, and clouds of ultralight bosons, as long as we can accurately model the dephasing they induce on the waveform of extreme mass-ratio inspirals (EMRIs). Most existing models rely on extrapolations from Newtonian results to model the interaction of the small black hole in an EMRI system with the environment surrounding the massive black hole. Here, we present a fully relativistic formalism to model such interaction with collisionless environments, focusing on the case of cold dark matter overdensities, like 'spikes' and 'mounds'. We implement our new formalism in the FastEMRIWaveforms framework and show that the resulting waveforms are significantly different from those based on a Newtonian treatment of environmental effects. Our results indicate that a fully relativistic treatment is essential to capture the environmental dephasing of GW signals from EMRIs accurately.

    ↳ gr-qcastro-ph.GAastro-ph.HEhep-phPRL(2025)·51 citations
23. 23*

    Lattice QCD calculations of hadron spectroscopy

    Sasa Prelovsek🇸🇮

    This chapter provides a pedagogical introduction to theoretical studies of hadrons based on the fundamental theory of strong interactions - Quantum ChromoDynamics. A perturbative expansion in the strong coupling is not applicable at hadronic energy scales. Lattice Quantum Chromodynamics is the formulation of the fundamental theory on a discrete space-time grid, which enables first-principles, systematically improvable, numerical simulations of strong interaction physics. This chapter explains how the masses of strongly stable and strongly decaying hadrons are determined. The strongly decaying hadrons have to be inferred from the corresponding scattering processes. Therefore, one of the main aims is to describe how the scattering amplitudes are extracted from a lattice simulation. The examples of spectra, widths, and scattering amplitudes are shown for conventional as well as exotic hadrons.

    ↳ hep-lathep-exhep-ph5 citations
24. 24*

    Searching for True Muonium in Relativistic Heavy Ion Collisions

    Zuo-Tang Liang🇨🇳 · Qian Yang🇨🇳 · Hong Zhang🇨🇳 · Jiaxing Zhao🇩🇪 · Pengfei Zhuang🇨🇳

    We investigate the production of the as-yet-undetected true muonium within the quark-gluon plasma formed in relativistic heavy-ion collisions, employing a relativistic Boltzmann transport framework coupled to viscous hydrodynamic simulations. The obtained effective cross sections for central collisions are 1.23~$\mu b$ in AuAu collisions with $\sqrt{s_{\mathrm{NN}}}=200$~GeV and 14.2~$\mu b$ in PbPb collisions with $\sqrt{s_{\mathrm{NN}}}=5.02$~TeV, resulting in a yield of $\mathcal{O}(10^4)$ and $\mathcal{O}(10^5)$ true muonium per billion $AA$ collisions at RHIC and the LHC, respectively. This establishes heavy-ion collisions as a promising process for detecting true muonium.

    ↳ nucl-thhep-ph3 citations
25. 25*

    Probing how bright the quark-gluon plasma glows in lattice QCD

    Ardit Krasniqi🇩🇪 · Marco Cè🇮🇹 · Tim Harris🇨🇭 · Renwick J. Hudspith🇺🇸 · Harvey B. Meyer🇩🇪

    Determining the spectrum of photons emitted by the quark-gluon plasma non-perturbatively remains an open computational challenge. In this letter we calculate two moments of that spectrum at a temperature $T\approx 254$MeV, employing lattice QCD with two flavors of $\mathrm{O}(a)$-improved Wilson fermions, without facing an inverse problem. Our central value for the difference of these two moments, which is sensitive to photon energies $\omega \gtrsim \pi T$, is lower than, but compatible with that obtained by integrating the leading-order weak-coupling photon spectrum. This study informs the $\text{direct photon puzzle}$ in heavy-ion collision phenomenology, where it has proved difficult to simultaneously explain the yield and azimuthal anisotropy of photons not originating from final-state hadronic decays.

    ↳ hep-lathep-phPRD(2025)·3 citations
26. 26*

    Phantom matters

    David Andriot🇫🇷

    Cosmological observations of the recent universe suggest that dark energy equation of state parameter $w$ is growing with time, departing from a cosmological constant for which $w=-1$. Standard quintessence models allow for a varying $w\ge -1$, but observations report that a phantom regime, $w<-1$, is quickly reached in the past. Often discarded because of uncertainties or parametrisation, we rather propose here to embrace the reality of this phantom regime. We revisit an elegant mechanism that accounts for it, thanks to a coupling of quintessence field(s) to matter (and possibly radiation). We show that this allows for steep scalar potentials, and illustrate this with string-inspired models, where $V=V_0{e}^{-\lambda \phi }$ and $\lambda \ge \sqrt{2}$. Those provide solutions in very good agreement with observations, including the phantom regime. We then discuss poles that can appear in $w$, making it diverge at recent times ($z\le 4$), and that could be detected by observations. We finally comment on an Early Dark Energy-like feature, that systematically appears for free from the models considered, and could be of interest for the Hubble tension.

    ↳ hep-thastro-ph.COgr-qchep-phPhys.Dark Univ.(2025)·36 citations
27. 27*

    Quark Propagator at one-loop in the Refined Gribov-Zwanziger framework

    Gustavo P. de Brito🇧🇷 · Philipe De Fabritiis🇧🇷 · Antonio D. Pereira🇧🇷

    The Refined Gribov-Zwanziger scenario is a local and renormalizable setup in which infinitesimal Gribov copies are eliminated and further non-perturbative effects are accounted for. The gluon propagator that arises from this framework fits lattice data very well in the Landau gauge. We investigate the coupling of quarks to this setting at one-loop order by computing the quark propagator. The fermionic sector is introduced by a minimal coupling and the non-perturbative effects are transmitted to the matter sector through gluonic loops which, in this case, carry information from the elimination of infinitesimal Gribov copies and the formation of condensates. We compare our findings with available lattice data both for the unquenched gluon propagator as well as for the quark propagator in the Landau gauge. Our results are comparable with those obtained in the Curci-Ferrari model at one-loop order. In particular, we are able to fit the unquenched gluon propagator and use the fixed parameters to predict the quark mass function and find good agreement with lattice data. However, the quark dressing function does not agree, even at a qualitative level, with lattice data in the infrared. This is agreement with the analogue computation in Curci-Ferrari model. Inspired by the developments in the Curci-Ferrari results, such a disagreement is likely to be cured by the inclusion of two-loops corrections. Finally, we compare the present minimal coupling with a non-perturbative matter coupling proposed in the Refined Gribov-Zwanziger literature.

    ↳ hep-thhep-lathep-phPRD(2025)·1 citation

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.