Tue·Jun 3, 2025Tuesday·June 3, 2025

1. 01*

   A New State of Matter between the Hadronic Phase and the Quark-Gluon Plasma?

   Yuki Fujimoto🇺🇸 · Kenji Fukushima🇯🇵 · Yoshimasa Hidaka🇯🇵 · Larry McLerran🇺🇸

   Lattice-QCD simulations and theoretical arguments hint at the existence of an intermediate phase of strongly interacting matter between a confined hadron gas and a deconfined Quark-Gluon Plasma (QGP). We qualitatively and semi-quantitatively explore and differentiate the phase structures in the temperature window from the QCD pseudo-critical temperature $T_c\simeq 160\text{MeV}$ to the pure-gluonic deconfinement temperature $T_d\simeq 285\text{MeV}$. We propose a three-regime picture using a hadron resonance gas (HRG) description augmented with the glueball spectrum based on the analysis of a large number, $N_c$, of colors. We estimate the entropy density from our model to confirm that the lattice-QCD data are bracketed with three regimes, i.e., a hadron gas, a QGP, and a new phase for $T_c\lesssim T\lesssim T_d$. In this new phase that we name a Spaghetti of Quarks with Glueballs (SQGB), thermal degrees of freedom of quarks are deconfined, yet gluons remain confined in glueballs. Since the Hagedorn temperature, $T_H\sim 285\text{MeV}$, is universal in the meson and the glueball sectors, in the infinite $N_c$ limit, the phase diagram in the plane of the baryon chemical potential and the temperature is reduced to the one with the confined and deconfined phases and Quarkyonic Matter at high density. At large but finite $N_c$, an SQGB window may open between these phases. We point out that the SQGB has interesting similarities with Quarkyonic Matter and that this matter in the large $N_c$ limit is confined as measured by the interaction between heavy quarks, but behaves in other respects like a quasi-free gas of quarks. As a result of the extrapolation to $N_c=3$, we present a revised phase diagram with the SQGB phase bounded by thermal crossovers. Finally, we give a quantitative analysis of chiral symmetry restoration in the SQGB phase.

   hep-phhep-latnucl-thPRD(2025)·35 citations
2. 02*

   Comparing effective temperatures in standard and Tsallis distributions from transverse momentum spectra in small collision systems

   Peng-Cheng Zhang🇨🇳 · Pei-Pin Yang🇨🇳 · Ting-Ting Duan🇨🇳 · Hailong Zhu🇨🇳 · Fu-Hu Liu🇨🇳 · Khusniddin K. Olimov🇺🇿

   The transverse momentum ($p_T$) spectra of identified light charged hadrons, specifically bosons (${\pi }^{\pm }$ and $K^{\pm }$) as well as fermions [$p(\bar{p})$], produced in small collision systems, namely deuteron-gold (d+Au) and proton-proton (p+p) collisions at the top energy of the Relativistic Heavy Ion Collider (RHIC) with a center-of-mass energy of $\sqrt{s_{NN}}=200$ GeV, are investigated in this paper. In present study, d+Au collisions are categorized into three centrality classes: central (0--20\%), semi-central (20--40\%), and peripheral (40--100\%) collisions. Various types of distributions, including standard [Bose-Einstein (Fermi-Dirac) and Boltzmann] and Tsallis distributions, are employed to fit the same $p_T$ spectra to derive different effective temperatures denoted as $T_{eff}$. The results indicate that $T_{eff}$ values obtained from Bose-Einstein, Boltzmann, Fermi-Dirac, and Tsallis distributions exhibit systematically a decreasing trend. Meanwhile, these $T_{eff}$ values also show a decreasing trend with a decrease in collision centrality. Furthermore, based on the spectra of given particles, a perfect linear relationship is observed between different pairwise combinations of $T_{eff}$ derived from both Boltzmann and Bose-Einstein (Fermi-Dirac) distributions as well as between Tsallis and Bose-Einstein (Fermi-Dirac) distributions.

   hep-phhep-exnucl-exnucl-thIndian J.Phys.(2026)·2 citations
3. 03*

   Bayesian inference of the magnetic field and chemical potential on holographic jet quenching in heavy-ion collisions

   Liqiang Zhu🇨🇳 · Zhan Gao🇨🇳 · Weiyao Ke🇨🇳 · Hanzhong Zhang🇨🇳

   Jet quenching is studied in a background magnetic field and a finite baryon chemical potential. The production of energetic partons is calculated using the next-to-leading order (NLO) perturbative Quantum Chromodynamics (pQCD) parton model, while the parton energy loss formula is obtained from the AdS/CFT correspondence incorporating the magnetic field and baryon chemical potential effects. Using Bayesian inference, we systemically compare the theoretical calculations with experimental data for the nuclear modification factor $R_{AA}$ of the large transverse momentum hadrons in different-centrality nucleus-nucleus collisions at 0.2, 2.76 and 5.02 TeV, respectively. The form of the holographic energy loss leads to a strong negative correlation between the magnetic field and the chemical potential after the calibration, from which we discussed the sensitivity of jet quenching phenomena to magnetic field and baryon chemical potential.

   hep-phCPC(2026)·5 citations
4. 04*

   Initial condition for the Balitsky-Kovchegov equation at next-to-leading order

   Carlisle Casuga🇫🇮 · Henri Hänninen🇫🇮 · Heikki Mäntysaari🇫🇮

   We determine the initial condition of the Balitsky-Kovchegov evolution equation at next-to-leading order (NLO) accuracy using HERA deep inelastic scattering data. Posterior distributions characterizing the initial condition are extracted using Bayesian inference. The total cross section and charm quark production data from HERA are found to provide stringent constraints on the posterior. These distributions quantify the uncertainty in the initial condition and serve as necessary input for propagating uncertainties to all NLO calculations within the Color Glass Condensate framework.

   hep-phnucl-thPRD(2025)·16 citations
5. 05*

   Quark Wigner distribution in frame-independent 3-dimensional space

   Sujit Janaa🇮🇳 · Vikash Kumar Ojha🇮🇳

   We investigate the quark Wigner distribution in a frame-independent, three-dimensional position space within the framework of the dressed quark model. It is observed that the distributions are concentrated near the center of the target and gradually diminish as one moves away in both the longitudinal and transverse directions. The distribution exhibits symmetry along both axes, indicating an equal probability of locating the quark in either direction around the center. Interestingly, the spatial profile of the distribution resembles that of atomic orbitals, where the probability of finding an electron is highest in certain regions compared to others.

   hep-ph0 citations
6. 06*

   A Novel Approach to Fast Calculation of High-Order Q-Cumulants

   L. Na{\dj}{\dj}er{\dj} · J. Milošević🇷🇸 · D. Devetak🇷🇸 · F. Wang🇺🇸 · X. Zhu🇨🇳

   The method of Q-cumulants has been shown as a powerful tool to study the fine details of the azimuthal anisotropies in high-energy nucleus-nucleus collisions. A new method for the fast calculation of arbitrary order Q-cumulant $v_n\{2k\}$ values, based on the partition of a non-negative integer l $\le$ m for calculation of the 2m-particle azimuthal correlations is presented in this paper. Unlike the standard Q-cumulants method in which the calculation of high-order multi-particle calculations is impractical, the newly proposed method enables easy calculation. The validity of the method is proven via a toy model that uses the elliptic power distribution to simulate anisotropic emission of particles. The method enables the study of fine details of the $v_2$ distribution, such as higher-order central moments of the $v_2$ distribution, as well as the hydrodynamic behavior of the Quark-Gluon Plasma.

   hep-phPRC(2026)·0 citations
7. 07*

   Regularization Prescription for the Mixing Between Nonlocal Gluon and Quark Operators

   Yao Ji🇨🇳 · Zhuoyi Pang🇨🇳 · Fei Yao🇺🇸 · Jian-Hui Zhang🇨🇳

   It is well-known that in the study of mixing between nonlocal gluon and quark bilinear operators there exists an ambiguity when relating coordinate space and momentum space results, which can be conveniently resolved through Mellin moments matching in both spaces. In this work, we show that this ambiguity is due to the lack of a proper regularization prescription of the singularity that arises when the separation between the gluon/quark fields approaches zero. We then demonstrate that dimensional regularization resolves this issue and yields consistent results in both coordinate and momentum space. This prescription is also compatible with lattice extractions of parton distributions from nonlocal operators.

   hep-phhep-latnucl-exnucl-thPRD(2026)·0 citations
8. 08*

   Decays of the vector charmonium and bottomonium hybrids

   B. Barsbay🇹🇷

   The full widths of the vector charmonium and bottomonium hybrid mesons $H_{\mathrm{c}}$ and $H_{\mathrm{b}}$, characterized by the quantum numbers $1^{--}$, are determined by analyzing their dominant strong decay modes: $H_{\mathrm{c}}\to D^{+}{D}^{-}$, $D_0{\overline{D}}_0$, $D_s^{+}{D}_s^{-}$ and $H_{\mathrm{b}}\to B^{+}{B}^{-}$, $B_0{\overline{B}}_0$. To evaluate the partial widths of these channels, we employ the QCD three-point sum rule approach, which provides a reliable method for extracting the strong coupling constants at the relevant hybrid-meson-meson interaction vertices. Based on this analysis, the full widths of these hybrid quarkonia are found to be ${\Gamma }_{H_{\mathrm{c}}}=(234.1\pm 37.4)\mathrm{MeV}$ and ${\Gamma }_{H_{\mathrm{b}}}=(78.8\pm 15.4)\mathrm{MeV}$ . These results are expected to facilitate the interpretation of future experimental data concerning the spectroscopy and decay patterns of exotic charmonium- and bottomonium-like hybrid mesons.

   hep-phhep-exhep-latEPJA(2025)·6 citations
9. 09*

   Unwinding the rare $\Omega$ sector: Fragmentation of fully charmed baryons from HL-LHC to FCC

   Francesco Giovanni Celiberto🇪🇸

   By adopting a hadron-structure-oriented approach, we present and discuss the release of the novel OMG3Q1.0 set of collinear fragmentation functions for fully charmed, rare $\Omega$ baryons. Our methodology combines diquark-like proxy model inputs for both charm-quark and gluon channels, calculated at the initial energy scales, with a DGLAP evolution that ensures a consistent treatment of heavy-quark thresholds, following directly from the HF-NRevo scheme. We complement our work with a phenomenological study of NLL/NLO${}^{+}$ resummed ${\Omega }_{3c}$ plus jet distributions using (sym)JETHAD at the HL-LHC and the future FCC. Unraveling the production mechanisms of rare, yet-unobserved hadrons, as provided by the OMG3Q1.0 functions, stands as a key asset for deepening our understanding of QCD at future high-energy hadron colliders.

   hep-phhep-exnucl-exnucl-thPRD(2025)·15 citations
10. 10*

    Centre-of-momentum frame analysis of $\eta$ production in DUNE

    R K Pradhan🇮🇳 · R Lalnuntluanga🇮🇱 · A Giri🇮🇳

    A deep understanding of neutrino-nucleus interaction is crucial for the precise measurement of neutrino oscillation parameters and cross section measurements. Various nuclear effects, such as initial state effects (IS) and Final state interactions (FSI), make neutrino interactions more complicated. To probe the impacts of the nuclear effects, a separate study of FSI and IS is required. A set of variables known as Centre-of-momentum (c.m.) variables (${\theta }_{c.m.}$ and $E_{c.m.}$) provides a unique approach to isolate the FSI effect with minimal sensitivity to IS. This work presents the importance of c.m. variables in neutrino-induced eta ($\eta$) meson production in the DUNE near detector. ${\theta }_{c.m.}$ is an important parameter to improve the FSI modeling, while $E_{c.m.}$ helps in isolating high-purity neutrino-Hydrogen events. The study of $\eta$ production in neutrino interactions helps in understanding the theoretical descriptions of higher resonance states.

    hep-phhep-exEPJC(2025)·0 citations
11. 11*

    Photon-induced production of the exotic charged charmonium-like state $Z_c(3900)$ off nuclear targets and its internal structure

    E. Ya. Paryev🇷🇺

    In this paper, we investigate the possibility to study the famous charged charmonium-like state $Z_c(3900)$ production off nuclear targets and its properties in inclusive photon-induced reactions near the kinematic threshold within the collision model based on the nuclear spectral function. The model accounts for its charged components $Z_c(3900{)}^{\pm }$ production in direct photon-nucleon interactions as well as three different popular scenarios for their internal structures: compact tetraquarks, molecules of the two open-charm mesons and mixtures of both of them. We calculate the absolute and relative excitation functions for production of $Z_c(3900{)}^{\pm }$ mesons on ${}^{12}$C and ${}^{184}$W target nuclei at initial photon energies of 9.0-17.5 GeV, the absolute momentum differential cross sections and their ratios for the $Z_c(3900{)}^{\pm }$ production off these target nuclei at laboratory polar angles of 0${}^{\circ }$-10${}^{\circ }$ and at photon energy of 14 GeV as well as the A-dependences of the ratios of the total cross sections for $Z_c(3900{)}^{\pm }$ production at photon energy of 14 GeV within the adopted scenarios for the $Z_c(3900{)}^{\pm }$ internal structures. We demonstrate that the absolute and relative observables considered show a certain sensitivity to the $Z_c(3900{)}^{\pm }$ internal structures which are by far the best known. Hence, they might be useful for the determination of these structures -- the issue which has attracted much attention in the hadron physics community -- from the comparison of them with the experimental data from the future high-precision experiments at the CEBAF facility.

    hep-phhep-exnucl-exnucl-thNPA(2025)·2 citations
12. 12*

    Investigating the leptonic couplings of doubly charged scalars at the muon collider

    Nivedita Ghosh🇯🇵 · Santosh Kumar Rai🇮🇳 · Tousik Samui🇮🇳 · Agnivo Sarkar🇮🇳

    We study the lepton flavour conserving and violating couplings of a doubly charged scalar at a 3 TeV muon collider. Using a model independent Lagrangian, we analyse the electron electron, muon muon, and tau tau final states mediated by the doubly charged scalar to probe individual couplings to mu e, mu mu, and mu tau. We find that for a doubly charged scalar of mass greater than 1 TeV and order one couplings, we achieve high signal significance in these channels. We delineate the collider s sensitivity in the mass vs coupling plane, highlighting the extensive reach of the muon collider in probing these couplings far beyond the current experimental limits. We also propose an angular distribution variable to discriminate the exchange of a doubly charged scalar from that of a neutral scalar, which give identical signals.

    hep-phPRD(2026)·6 citations
13. 13*

    $\lambda$ and $\rho$ Regge trajectories for the pentaquark $P_{cc\bar{c}bb}$ in the diquark-triquark picture

    He Song🇨🇳 · Xin-Ru Liu🇨🇳 · Jia-Qi Xie🇨🇳 · Jiao-Kai Chen🇨🇳

    We propose the Regge trajectory relations for the fully heavy pentaquark $P_{cc\bar{c}bb}$ utilizing both diquark and triquark Regge trajectory relations. Using these new relations, we discuss four series of Regge trajectories: the ${\rho }_1$-, ${\rho }_2$-, ${\lambda }_1$-, and ${\lambda }_2$-trajectories. We provide rough estimates for the masses of the ${\rho }_1$-, ${\rho }_2$-, ${\lambda }_1$-, and ${\lambda }_2$-excited states. Except for the ${\lambda }_1$-trajectories, the complete forms of the other three series of Regge trajectories for the pentaquark $P_{cc\bar{c}bb}$ are lengthy and cumbersome. We show that the ${\rho }_1$-, ${\rho }_2$-, and ${\lambda }_2$-trajectories can not be obtained by simply imitating the meson Regge trajectories because mesons have no substructures. To derive these trajectories, pentaquark's structure and substructure should be taken into consideration. Otherwise, the ${\rho }_1$-, ${\rho }_2$-, and ${\lambda }_2$-trajectories must rely solely on fitting existing theoretical or future experimental data. Consequently, the fundamental relationship between the slopes of the obtained trajectories and constituents' masses and string tension will become unobvious, and the predictive power of the Regge trajectories would be compromised. Moreover, we show that the lengthy complete forms of the ${\rho }_1$-, ${\rho }_2$-, and ${\lambda }_2$-trajectories can be well approximated by the simple fitted formulas. Four series of Regge trajectories for the pentaquark $P_{cc\bar{c}bb}$ all exhibit a behavior of $M\sim x^{2/3}$, where $x=n_{r_1},n_{r_2},l_1,l_2,N_{r_1},N_{r_2},L_1,L_2$. All four series of trajectories exhibit concave downward behavior in the $(M^2,x)$ plane.

    hep-phJHEP(2025)·5 citations
14. 14*

    Hadrons in group expansion

    Hua-Xing Chen🇨🇳

    Various approximate symmetries exist in nature. For example, the flavor $SU(4)$ symmetry involving the $up/down/strange/charm$ quarks is severely broken, the flavor $SU(3)$ symmetry involving the $up/down/strange$ quarks is moderately broken, and the isospin $SU(2)$ symmetry involving the $up/down$ quarks is slightly broken. These broken symmetries are primarily governed by the strong interaction, making them an ideal platform for investigating the general behavior of approximate symmetries. To explore the application of the flavor $SU(4)$ group to ground-state baryons, we systematically calculate the transition matrices associated with various flavor $SU(4)$ representations as well as the matrices that describe their connections. These matrices are then employed to analyze the mass spectrum of ground-state baryons. Our results indicate that these states can be described as mixtures of various flavor representations, such as ${\Sigma }_c/{\Xi }_c^{\prime }/{\Omega }_c\sim 20_{\mathbf{M}}\oplus 20_{\mathbf{S}}\oplus {\bar{4}}_{\mathbf{A}}[SU(4)]$, ${\Xi }_c/{\Xi }_c^{\prime }\sim {\bar{3}}_{\mathbf{A}}\oplus 6_{\mathbf{S}}[SU(3)]$, ${\Lambda }^0/{\Sigma }^0\sim 1_{\mathbf{A}}\oplus 3_{\mathbf{S}}[SU(2)]$, where the subscripts $\mathbf{S}$, $\mathbf{A}$, and $\mathbf{M}$ denote the symmetric, antisymmetric, and mixed flavor wave functions, respectively. Our results also indicate that the flavor symmetries, as they break, necessitate the mixing of these flavor representations according to specific rules. For example, the approximate $SU(3)$ flavor decuplet, with one of its flavor components slightly differing from the other two, deviates from the exact $SU(3)$ flavor decuplet, and this deviation is characterized by the exact $SU(3)$ flavor octet.

    hep-phhep-thmath-phmath.MP1 citation
15. 15*

    Emergent symmetry in a two-Higgs-doublet model from quantum information and nonstabiliserness

    Giorgio Busoni🇦🇺 · John Gargalionis🇦🇺 · Ewan N. V. Wallace🇦🇺 · Martin J. White🇦🇺

    Studies of scattering processes in scalar models with two Higgs doublets have recently hinted at a connection between the absence of flavour-space entanglement in ${\Phi }^{+}{\Phi }^0$ scattering and an emergent $\mathrm{SO}(8)$ symmetry in the scalar potential. We extend the analysis to all scattering channels with two particles in the external states by treating the process as a four-qubit system in the weak isospin and flavour subspaces of the $2$-particle state. We work with a generic quantum information-theoretic principle encoded by the commutativity of the initial state density matrix with the transition matrix (at leading order in perturbation theory). This yields a special case of the entanglement minimisation conditions previously derived in the literature, and we interpret the principle in terms of the conservation of non-stabiliserness (or magic). Working at leading order in the quartic couplings, we find a consistent set of conditions that implies an $\mathrm{SO}(8)$ symmetry on the quartic part of the potential for scattering an arbitrary initial state, but a smaller $\mathrm{SU}(2{)}_R$ symmetry when the initial state is chosen to have definite isospin. This follows by accounting for Bose symmetry in the initial state, which introduces entanglement between the isospin and flavour subspaces.

    hep-phhep-thquant-phPRD(2025)·29 citations
16. 16*

    Thermal dilepton production within conformal viscous Gubser flow

    Lakshmi J. Naik🇮🇳 · V. Sreekanth🇮🇳

    By employing the Gubser solutions of causal relativistic second-order Israel-Stewart hydrodynamics, we study the thermal dilepton production from heavy-ion collisions, considering the transverse expansion of the viscous hot QCD medium along with longitudinal boost-invariance. We analyze the evolution of the temperature and shear stress profiles of the QCD matter under Gubser flow for different values of the associated parameter $q$ (inverse length scale). We study the dilepton production using leading order Born rates from QGP and hadronic sectors under Gubser geometry. Viscous modified dilepton rate is calculated using the first-order Chapman-Enskog (CE) like non-equilibrium correction of the particle distribution function. Our study indicates that lower values of $q$ result in the enhancement of the emitted dilepton spectra. We also determine the effective temperature of the hot QCD medium from the inverse slope of transverse mass spectra, for different $q$. We find that the effective temperature determined from the dilepton spectra for a smaller system to be higher. Further, we compare the strength of CE like and Grad's viscous correction to the ideal dilepton spectra and find that CE type viscous corrections are well behaved compared to that of Grad's in the presence of transverse flow.

    hep-phnucl-thEPJC(2025)·4 citations
17. 17*

    Biased rate estimates in bump-hunt searches

    William Murray🇬🇧 · Matt O'Neill🇬🇧 · Finn O'Gara🇬🇧

    The cleanest way to discover a new particle is generally the "bump-hunt" methodology: looking for a localised excess in a mass (or related) distribution. However, if the mass of the particle being discovered is not known the procedure of quoting the most significant excess seen is "greedy", and random fluctuations from the background can be merged with the signal. This means that an observed 3{\sigma} evidence probably has the rate over-estimated by of order 10% and the mass uncertainty underestimated by more like 20%. If the width of the particle being discovered is also unknown, or the experimental resolution uncertain, the effect grows larger. In the context of LHC, the data-doubling period is now measured in years. If evidence for a genuine signal is obtained at the 3{\sigma} level, the true signal rate probably corresponds to a lower significance. The additional data required to produce a 5{\sigma} discovery may be hundreds of inverse femtobarn more than might be naively expected.

    hep-ph0 citations
18. 18*

    Application range of perfect spin hydrodynamics

    Zbigniew Drogosz🇵🇱 · Wojciech Florkowski🇵🇱 · Valeriya Mykhaylova🇵🇱

    The application range of perfect spin hydrodynamics is studied in two cases: one based on the classical spin description and the other using a quantum spin density matrix (Wigner function). Different forms of the conditions connecting the components of the spin polarization tensor, particle mass, temperature, and hydrodynamic flow are introduced, and their mutual relations are explained. The results obtained are important for practical applications of spin hydrodynamics to model heavy-ion collisions.

    hep-phnucl-thPRD(2025)·7 citations
19. 19*

    Dynamical dark energy in the no-scale Brans-Dicke gravity

    Muzi Hong🇯🇵 · Kyohei Mukaida🇯🇵 · Tsutomu T. Yanagida🇯🇵

    We add a new scalar field in the no-scale Brans-Dicke gravity and require it to have a global O(2) symmetry with the original scalar field in the Brans-Dicke gravity. This gives us a new massless scalar field in the Einstein frame due to the SO(2) symmetry. We then explicitly break the O(2) symmetry to a $D_4$ symmetry, and this scalar field gains a periodic potential. This scalar field can serve as the quintessence field to explain dark energy. If we further add the $R^2$ term and the non-minimal coupling to the Higgs field, we can realize inflation and reheating, and this leads to a super-Planckian decay constant of the quintessence potential. The super-Planckian decay constant is consistent with the newly released observational data according to a recent analysis.

    hep-phastro-ph.COgr-qchep-thPLB(2025)·4 citations
20. 20*

    Searching for charged Higgs bosons via $e^{+}{e}^{-}\to H^{\pm }{W}^{\mp }S$ at the ILC

    Brahim Ait Ouazghour🇲🇦 · Abdesslam Arhrib🇲🇦 · Kingman Cheung🇹🇼 · Es-said Ghourmin🇲🇦 · Mohamed Krab🇹🇼 · Larbi Rahili🇲🇦

    We investigate the phenomenology of the charged Higgs boson at the International Linear Collider (ILC) within the framework of the type-X Two-Higgs Doublet Model (2HDM), where a light charged Higgs boson, with a mass around 200 GeV or even smaller than top quark mass, is still being consistent with flavor physics data as well as with the colliders experimental data. In the theoretically and experimentally allowed parameter space, the $e^{+}{e}^{-}\to H^{\pm }{W}^{\mp }S$ (with $S=H,A$) production processes can yield signatures with event rates larger than those from $e^{+}{e}^{-}\to H^{+}{H}^{-}$ and offer sensitivity to the Higgs mixing parameter $\sin (\beta -\alpha )$. We consider the bosonic $H^{\pm }\to W^{\pm }S$ decays, where the neutral scalar $S$ further decays into a pair of tau leptons. We show, through a detector-level Monte Carlo analysis, that the resulting $[\tau \tau ][\tau \tau ]WW$ final state could be seen at the ILC with at least 500 GeV center-of-mass energy and 500 fb${}^{-1}$ of luminosity.

    hep-phPRD(2025)·6 citations
21. 21*

    An Effective Sphaleron Awakens

    Xu-Xiang Li🇺🇸 · Michael J. Ramsey-Musolf🇨🇳 · Tuomas V. I. Tenkanen🇨🇳 · Yanda Wu🇨🇳

    Using thermal effective field theory, we present a self-consistent perturbative formulation of the Higgs phase sphaleron rate after a radiatively-induced first-order phase transition. This gauge-invariant formulation is based on dimensionally reduced effective field theory (3D EFT) at high temperatures and paves a way for including higher order corrections within the 3D EFT perturbation theory without double counting. Concretely, we compute the Higgs phase sphaleron rate in a semi-classical approximation within the two-loop resummed 3D EFT. We find compact results for the sphaleron rate and the baryon washout factor as well as criteria for the baryon number preservation by providing a clear connection to the results obtained using a similar 3D EFT description for the bubble nucleation. We demonstrate these calculations for the real triplet-extended Standard Model, and conclude that when all two-loop thermal effects for the matching are accounted, no sufficiently strong one-step electroweak phase transitions exist within the parameter space regime that can be mapped onto the 3D EFT we have considered.

    hep-ph17 citations
22. 22*

    Higher-order soft and virtual corrections in $pp\to \gamma W$ production at the LHC

    Nikolaos Kidonakis🇺🇸 · Alberto Tonero🇺🇸

    We study higher-order QCD corrections beyond NLO for the associated production of a photon with a $W$ boson ($\gamma W^{+}$ and $\gamma W^{-}$ production) at the Large Hadron Collider. We calculate the NNLO soft-plus-virtual QCD corrections as well as the N${}^3$LO soft-gluon corrections to the total production cross section and the photon transverse-momentum distribution in single-particle-inclusive kinematics. The higher-order corrections provide a significant enhancement to the cross section. This is the first calculation of the complete soft-gluon corrections at N${}^3$LO in single-particle-inclusive kinematics for a Standard Model process.

    hep-phEPJC(2025)·3 citations
23. 23*

    Status of the W boson mass and the future of the electroweak fit in the next decades

    Giuseppe Bozzi🇮🇹 · Matthias Schott🇩🇪

    A precise determination of the W boson mass is an essential test for the Standard Model of particle physics: the comparison of experimental value and theoretical prediction allows to probe the internal consistency of the electroweak sector and could possibly highlight signals of New Physics. We provide a concise and up-to-date summary of past and recent measurements at lepton and hadron colliders, a discussion of the known perturbative and non-perturbative theoretical ingredients used to provide predictions for the relevant observables, and an overview of future prospects to reduce systematic uncertainties and to compare different measurements in a consistent way. We conclude with a brief discussion on the relevance of the global electroweak fit at present and future colliders.

    hep-phhep-ex2 citations
24. 24*

    Parity solves the Strong CP problem

    Ravi Kuchimanchi🇺🇸

    A recent paper "What can solve the strong CP problem?" goes counter to conventional wisdom by arguing that the universe was in an initial state that combines different eigenstates of $\theta$ (of the theta vacuum of QCD), and asserts that for such an initial state, axionless solutions to the Strong CP Problem based on P and CP symmetries will not work. We discuss the nature of the theta vacuum in light of this work, and find that the conventional framing and solutions based on P and CP symmetries are on a firm footing.

    hep-ph3 citations
25. 25*

    Anisotropy effects on heavy quark dynamics in Gribov modified gluon plasma

    Sumit🇨🇳 · Jai Prakash🇨🇳 · Santosh Kumar Das🇮🇳 · Najmul Haque🇮🇳

    In the early stages of relativistic heavy-ion collisions, the quark-gluon plasma momentum distribution is anisotropic, leading to instabilities driven by chromomagnetic plasma modes. In this work, we consider the anisotropic momentum distribution of the medium constituents to investigate its effects on charm and bottom quark dynamics using the nonperturbative Gribov resummation approach within the Fokker-Planck equation framework. Specifically, we investigate the impact of nonperturbative effects and weak anisotropies on the heavy-quark transport coefficients, accounting for the angular dependence of the anisotropy vector relative to the heavy-quark motion direction. Furthermore, the calculated drag and diffusion coefficients are used to estimate heavy-quark energy loss and the nuclear modification factor, accounting for both elastic and inelastic collisions. Our findings indicate that momentum anisotropy, angular dependence, and nonperturbative effects-captured through the scattering amplitudes-play a significant role in determining the transport properties of heavy quarks.

    hep-phnucl-thJ.Phys.G(2026)·2 citations
26. 26*

    Energy loss and theoretical uncertainties in small quark-gluon plasmas

    Coleridge Faraday🇿🇦

    We present a perturbative-quantum-chromodynamics-based energy loss model with small system size corrections to both radiative and elastic energy loss, incorporating realistic collision geometry, production spectra, and fragmentation. We use the Djordjevic-Gyulassy-Levai-Vitev (DGLV) radiative energy loss model and add back in previously neglected terms suppressed by system size. This small system size correction, derived by Kolbe and Horowitz, is large for high-momentum pions, raising concerns about key approximations in the radiative energy loss. We analyse the self-consistency of these approximations, finding that a particular approximation - the large formation time approximation - is not satisfied self-consistently within the model. We explore a kinematic cutoff on the transverse radiated gluon momentum, which restores the self-consistency of this approximation, but at the cost of an increased sensitivity to the exact cutoff chosen. We investigate the common application of the central limit theorem to approximate the elastic energy loss as a Gaussian distribution. Our results are insensitive to this approximation - understood not by many scatterings, but rather from an expansion of $R_{AA}$ in terms of moments of the energy loss probability distributions. We also explore uncertainty from the crossover between hard thermal loop and vacuum propagators. We perform a one-parameter fit of the strong coupling ${\alpha }_s$ to RHIC and LHC large-system data, accounting for two important theoretical uncertainties. Most uncertainties can be absorbed into a shift in ${\alpha }_s$, but residual uncertainty bands remain. Differences in elastic energy loss persist even after the fit, producing distinct $p_T$ and system size dependencies. We show model predictions for $p/d/{}^3\text{He}+A$ collisions, finding agreement with RHIC small system data but disagreement with LHC results.

    hep-ph0 citations
27. 27*

    Differential Equations for Energy Correlators in Any Angle

    Rourou Ma🇨🇳 · Jianyu Gong🇨🇳 · Jingwen Lin🇨🇳 · Kai Yan🇨🇳 · Gang Yang🇨🇳 · Yang Zhang🇨🇳

    Energy Correlators (EC) are the simplest IR finite observables, which connect theories and experiments. In this paper, we provide a systematic algorithm to calculate the canonical differential equations for energy correlators at generic angle in $\mathcal{N}=4$ super Yang-Mills theory. The integrand is obtained from the 5-point form factor square for scalar half-BPS operators. Applying the algorithm, we obtain the canonical basis for three-point EC and the full set of master integrals for four-point EC. We analyze the function space for four-point case. For multiple polylogrithmic (MPLs) integrals, we calculate their symbols, and for integrals beyond MPLs, we make further investigation by Picard-Fuchs operators. We find two elliptic curves and one genus 2 hyperelliptic curve. The results are achieved by means of integration by part (IBP) reduction and differential equations powered by computational algebraic geometry methods. We provide a package that implements the algorithm. The data is a valuable reference for exploring the structure of physical observables in perturbation theories.

    hep-phhep-thJHEP(2026)·8 citations
28. 28*

    Learning about neutron star composition from the slope of the mass-radius diagram

    Márcio Ferreira🇵🇹 · Constança Providência🇵🇹

    The slope of the neutron star mass-radius curve, $dM/dR$, is studied to understand the information it may carry about the composition of neutron stars, particularly with regard to the presence of non-nucleonic degrees of freedom. This study uses two large sets of relativistic mean-field equations of state with either nucleonic or nucleonic and hyperonic degrees of freedom, and imposes constraints obtained from GW170817 and the pulsars PSR J0030+0451 and PSR J0740+6620. It is shown that: i) some mass-radius curves are characterized by a negative slope from one solar mass up to the maximum mass; ii) other equations of state (EoS) have a positive slope for a given range of masses below the maximum star mass. Within the set of models considered, the first set includes only a very small number of hyperonic EoS: less than 0.5\% of the total number of hyperonic stars and approximately one third of the nucleonic EoS. We have also analyzed the sign of the slope for neutron star masses of 1.2, 1.4 and 1.8$M_{\odot }$. Only approximately 1\% of hyperonic equations of state (EoS) predict a negative slope for 1.4$M_{\odot }$ stars, whereas over 90\% of nucleonic stars have a negative slope at this mass. Finally, almost all stars have a negative slope at 1.8$M_{\odot }$. A positive slope at 1.4$M_{\odot }$ may indicate the presence of non-nucleonic degrees of freedom within neutron stars. The nuclear matter property that distinguishes the different scenarios most clearly is the curvature of the symmetry energy. Nucleonic EoSs with a positive slope $dM/dR$ predict the highest values, which can exceed 100 MeV.

    ↳ nucl-thastro-ph.HEhep-phPRD(2025)·12 citations
29. 29*

    Forecast Constraints on Bouncing Cosmology from High Frequency Gravitational Waves Using Superconducting LC Circuits and Resonant Cavities

    Changhong Li🇨🇳

    We exploit forecast sensitivities to high frequency gravitational waves (HFGWs) from superconducting LC circuits, traditional resonant cavity and superconducting radio frequency (SRF) cavities with electromagnetic and mechanical modes to derive the first projections of the bounce energy scale within the generic bouncing cosmology framework over the frequency window $1$kHz $\lesssim f\lesssim 10$GHz. In comparison with existing astrophysical limits (spanning $10^{-17}$Hz $\lesssim f\lesssim 1$kHz and based on Planck/BICEP, PTA, and aLIGO/LISA) our HFGW forecasts yield substantially tighter constraints across a broad region of parameter space. This work unifies constraints from cosmological observations and quantum measurement experiments, providing comprehensive coverage of the early Universe gravitational wave spectrum from $10^{-17}\mathrm{Hz}$ to $10\mathrm{GHz}$ and thereby probing the cosmic initial non singularity at ultra high energy scales.

    ↳ astro-ph.COhep-ph2 citations
30. 30*

    Exponential speedup in quantum simulation of Kogut-Susskind Hamiltonian via orbifold lattice

    Georg Bergner🇩🇪 · Masanori Hanada🇬🇧 · Emanuele Mendicelli🇬🇧

    We demonstrate that the orbifold lattice Hamiltonian -- an approach known for its efficiency in simulating SU($N$) Yang-Mills theory and QCD on digital quantum computers -- can reproduce the Kogut-Susskind Hamiltonian in a controlled limit. We show that it emerges naturally as the infinite scalar mass limit of the orbifold lattice formulation, even at finite lattice spacing. Our analysis provides both a general analytical framework applicable to SU($N$) gauge theories in arbitrary dimensions and specific numerical evidence for $(2+1)$-dimensional SU($N$) Yang-Mills theories ($N=2,3$). Using Euclidean path integral methods, we quantify the approach to this limit by comparing the standard Wilson action with the orbifold lattice action, matching lattice parameters, and systematically extrapolating results as the bare scalar mass approaches infinity. This reformulation resolves longstanding technical obstacles and offers a straightforward implementation protocol for digital quantum simulation of the Kogut-Susskind Hamiltonian with exponential speedup compared to classical methods and previously known quantum methods, modulo standard assumptions made also for the original Kogut-Susskind approach. We emphasize that the present work establishes this equivalence using classical Euclidean Monte Carlo; the exponential speedup itself is a property of quantum simulation of the orbifold Hamiltonian established in earlier work, which the equivalence shown here lets one inherit for the Kogut-Susskind Hamiltonian.

    ↳ quant-phhep-lathep-phhep-th+19 citations
31. 31*

    Updated Constraints on the Injection Energy of Positrons Generating the Galactic 511 keV $\gamma$-ray line

    Souradeep Das🇦🇺 · Mark R. Krumholz🇦🇺 · Roland M. Crocker🇦🇺 · Thomas Siegert🇩🇪 · Laura Eisenberger🇩🇪

    Even 50 years after the discovery of a positron annihilation line from the inner Galaxy, no class of astrophysical sources has emerged as a definitive explanation for both the emission morphology and flux. Positrons produced by dark matter annihilation or decay have been proposed, but the mass of any such candidate is constrained by continuum $\gamma$-ray emission at energies $>511$ keV. Earlier analyses have claimed that this emission requires that the positrons have kinetic energies less than a few MeV at injection, disfavoring both much of the dark matter parameter space and many potential compact astrophysical source classes such as pulsars. However, these constraints were not based on a full forward model of the absolute flux of the $\gamma$-ray line and continuum data, and did not marginalize over uncertainties about the relative angular distributions of the line and continuum. Here we describe an improved analysis that overcomes these limitations, and show that constraints on the injection energy are much weaker than previously claimed; even under conservative assumptions the data are consistent with initial energies up to $\sim 110$ MeV from INTEGRAL/SPI data alone, and up to $\sim 55$ MeV when including COMPTEL and EGRET data, subject to cross-normalization between them and INTEGRAL.

    ↳ astro-ph.HEastro-ph.GAhep-ph7 citations
32. 32*

    Contact potentials in presence of a regular finite-range interaction using dimensional regularization and the $N/D$ method

    David R. Entem🇪🇸 · Juan Nieves🇪🇸 · Jose Antonio Oller🇪🇸

    We solve the Lippman-Schwinger equation (LSE) with a kernel that includes a regular finite-range potential and additional contact terms with derivatives. We employ distorted wave theory and dimensional regularization, as proposed in Physics Letters B 568 (2003) 109. We analyze the spin singlet nucleon-nucleon $S-$wave as case of study, with the regular one-pion exchange (OPE) potential in this partial wave and up to $\mathcal{O}(Q^6)$ (six derivatives) contact interactions. We discuss in detail the renormalization of the LSE, and show that the scattering amplitude solution of the LSE fulfills exact elastic unitarity and inherits the left-hand cut of the long-distance OPE amplitude. Furthermore, we proof that the LSE amplitude coincides with that obtained from the exact $N/D$ calculation, with the appropriate number and typology of subtractions to reproduce the effective range parameters taken as input to renormalize the LSE amplitude. The generalization to higher number of derivatives is straightforward.

    ↳ nucl-thhep-phPRD(2025)·4 citations
33. 33*

    Probing Cosmic Curvature with Fast Radio Bursts and DESI DR2

    Jéferson A. S. Fortunato · Wiliam S. Hipólito-Ricaldi · Gustavo E. Romero

    The spatial curvature of the Universe remains a central question in modern cosmology. In this work, we explore the potential of localized Fast Radio Bursts (FRBs) as a novel tool to constrain the cosmic curvature parameter ${\Omega }_k$ in a cosmological model-independent way. Using a sample of 120 FRBs with known redshifts and dispersion measures, we reconstruct the Hubble parameter $H(z)$ via artificial neural networks, and use it to obtain angular-diameter distances $D_A(z)$ through two complementary approaches. First, we derive the comoving distance $D_C(z)$ and $D_A(z)$ directly from FRBs without assuming a fiducial cosmology. Then, we combine the FRB-based $H(z)$ with Baryon Acoustic Oscillation (BAO) DESI DR2 measurements to infer $D_A(z)$. By comparing the FRB-derived and BAO+FRB-derived $D_A(z)$, we constrain spatial curvature. Our covariance-based likelihood (accounting for correlated uncertainties) yields ${\Omega }_k=-0.31\pm 0.57$, while a diagonal (Gaussian) treatment gives ${\Omega }_k=-0.13\pm 0.46$. Both estimations are consistent with spatial flatness at the $1\sigma$ level, albeit with a mild preference for negative curvature. Explicitly accounting for the full covariance broadens the intervals and avoids underestimation of uncertainties. These results highlight the growing relevance of FRBs in precision cosmology and their synergy with BAO as a powerful, cosmological model-independent probe of the large-scale geometry of the Universe.

    ↳ astro-ph.COhep-phPRD(2026)·9 citations
34. 34*

    The Exact and Approximate Tales of Boost-Breaking Cosmological Correlators

    Zhehan Qin🇨🇳 · Sébastien Renaux-Petel🇫🇷 · Xi Tong🇬🇧 · Denis Werth🇫🇷 · Yuhang Zhu🇰🇷

    Cosmological correlators offer a remarkable window into the high-energy physics governing Universe's earliest moments, with the tantalising prospect of discovering new particles. However, extracting new physics from these observables requires both precise theoretical predictions of inflationary theories and accurate, analytical templates suitable for data analysis throughout parameter and kinematic spaces. In this paper, we extend the current analytical results by computing the most general boost-breaking seed correlator mediated by the tree-level exchange of a massive spinning particle. We derive the result using two complementary approaches, bootstrapping from boundary differential equations, and direct spectral integration. Both representations are packaged as a single partially resummed series that converges in all physical kinematics. Computing this correlator marks a milestone for carving out the space of all boost-breaking correlators, and therefore completes the tree-level catalogue. We then introduce a general procedure to obtain accurate approximations for cosmological collider signals based on the saddle-point method. This approach allows for a clear physical intuition of various signals hidden in correlators, as the bulk physics is made manifest through the location of these saddles in the complex time plane, which depend on the external kinematics. Evaluating the time integrals at these saddles yields results given as elementary functions that remain valid beyond soft limits and provide intuitive control over both the signal shape and amplitude. We demonstrate the power of this method in both de Sitter-invariant and boost-breaking scenarios, and uncover novel refined waveform and strength dependence for oscillatory signals from massive fields. We provide a complete cosmological collider shape template capturing all boost-breaking effects for upcoming cosmological surveys.

    ↳ hep-thastro-ph.COgr-qchep-phJCAP(2025)·24 citations
35. 35*

    Anomalous non-thermal fixed point in a quasi-two-dimensional dipolar Bose gas

    Niklas Rasch · Lauriane Chomaz🇩🇪 · Thomas Gasenzer🇩🇪

    The emergence of distinctly sub-diffusive scaling in the vicinity of an anomalous non-thermal fixed point is discussed in a quasi-two-dimensional dipolar Bose gas in the superfluid phase, carrying ensembles of vortices and antivortices with zero net angular momentum. The observed scaling behavior reflects coarsening dynamics driven by the mutual annihilation of vortices and antivortices, with the mean inter-defect distance growing algebraically over time as ${\ell }_{\text{v}}(t)\sim t^{\beta }$. A sub-diffusive ($\beta <1/2$) exponent $\beta \approx 0.2$ is extracted for various parameter regimes, initial conditions, and dipolar configurations from both scaling occupation-number spectra and the evolution of inter-defect distances as well as the corresponding total vortex densities. As vortex-antivortex annihilation progresses, excitations of the background condensate increase. This gives rise to a transition in the scaling behavior at late times, toward a non-thermal fixed point governed by diffusion-type scaling with $\beta \approx 1/2$ as expected for the mutual annihilation of well-separated vortex-antivortex dipoles. While the temporal scaling with $\beta$ does not depend significantly on the strength and anisotropy of the dipolar interactions and thus underlines the universality of the anomalous as well as diffusion-type non-thermal fixed points, we find distinctly different vortex patterns resulting in the dipolar case. While in the superfluid with contact interactions only, same-sign vortices tend to cluster and form large-scale eddies, in the dipolar and tilted cases, roton excitations appear to prevent such motion, giving rather rise to a maximisation of distances between vortices of either sign.

    ↳ cond-mat.quant-gashep-phPRA(2025)·2 citations
36. 36*

    Toward extracting scattering phase shift from integrated correlation functions IV: Coulomb corrections

    Peng Guo🇺🇸 · Frank X. Lee🇺🇸

    The formalism developed in Refs.~\cite{Guo:2023ecc,Guo:2024zal,Guo:2024pvt} that relates the integrated correlation functions for a trapped system to the infinite volume scattering phase shifts through a weighted integral is further extended to include Coulomb interaction between charged particles. The original formalism cannot be applied due to different divergent asymptotic behavior resulting from the long-range nature of the Coulomb force. We show that a modified formula in which the difference of integrated correlation functions between particles interacting with Coulomb plus short-range interaction and with Coulomb interaction alone is free of divergence, and has rapid approach to its infinite volume limit. Using an exactly solvable model, we demonstrate that the short-range potential scattering phase shifts can be reliably extracted from the formula in the presence of Coulomb interaction.

    ↳ hep-latcond-mat.othercond-mat.quant-gashep-ph+1PRD(2025)·6 citations
37. 37*

    Gauge-invariant Slavnov-Taylor Decomposition for Trilinear Vertices

    Andrea Quadri🇮🇹

    We continue the analysis of the gauge-invariant decomposition of amplitudes in spontaneously broken massive gauge theories by providing a characterization of separately gauge-invariant subsectors for amplitudes involving trilinear interaction vertices for an Abelian theory with chiral fermions. We show that the use of Frohlich-Morchio-Strocchi gauge-invariant dynamical (i.e. propagating inside loops) fields yields a very powerful handle on the cancellations among unphysical degrees of freedom (the longitudinal mode of the massive gauge field, the Goldstone scalar and the ghosts). The resulting cancellations are encoded into separately Slavnov-Taylor invariant sectors for 1-PI amplitudes. The construction works to all orders in perturbation theory. This decomposition suggests a novel strategy for the determination of finite counter-terms required to restore the Slavnov-Taylor identities in chiral theories in the absence of an invariant regularization scheme.

    ↳ hep-thhep-phUniverse(2025)·0 citations
38. 38*

    On-shell recursion relations for higher-spin Compton amplitudes

    Yohei Ema🇨🇭 · Ting Gao🇺🇸 · Wenqi Ke🇺🇸 · Zhen Liu🇺🇸 · Ishmam Mahbub🇺🇸

    We recursively construct tree-level electromagnetic and gravitational Compton amplitudes of higher-spin massive particles by the all-line transverse momentum shift. With three-point amplitude as input, we demonstrate that higher-point electromagnetic and gravitational Compton amplitudes are on-shell constructible up to spin $s=3/2$ and $s=5/2$, respectively, under the all-line transverse shift after imposing the current constraint condition. We unambiguously derive the four-point electromagnetic and gravitational Compton amplitudes for $s\le 3/2$ and $s\le 5/2$, which are uniquely determined by the on-shell recursion relation and are free from unphysical spurious poles. In addition, we explore amplitudes of spin-$3/2$ particles with non-minimal three-point interactions with photon, as well as $s>3/2$ particles, and comment on their notable features. Our work furthers the understanding of on-shell methods for massive amplitudes, with hopes to shed light on physical observables in particle physics and higher-spin amplitudes relevant for Kerr black-hole scattering.

    ↳ hep-thgr-qchep-phJHEP(2026)·6 citations
39. 39*

    The particle spectra of parity-violating theories: A less radical approach and an upgrade of PSALTer

    Will Barker🇨🇿 · Georgios K. Karananas🇩🇪 · Haochen Tu🇬🇧

    Due to computational barriers, the effects of parity violation have so far been grossly neglected in gravitational model-building, leading to a serious gap in the space of prior models. We present a new algorithm for efficiently computing the particle spectrum for any parity-violating tensorial field theory. It allows to extract conditions for the absence of massive ghosts without resorting to any manipulation of radicals in cases where the particle masses are irrational functions of the Lagrangian coupling coefficients. We test it against several examples, among which is the most general parity-indefinite Einstein-Cartan/Poincaré gravity that propagates two healthy massive scalars (in addition to the massless graviton). Importantly, we upgrade the PSALTer software in the Wolfram Language to accommodate parity-violating theories. PSALTer is a contribution to the xAct project.

    ↳ hep-thgr-qchep-phPRD(2025)·6 citations
40. 40*

    Primordial Gravitational Waves from Phase Transitions during Reheating

    Amitayus Banik🇰🇷 · Nicolás Bernal🇦🇪 · Fazlollah Hajkarim🇺🇸

    We study primordial gravitational waves (GWs) generated from first-order phase transitions (PTs) during cosmic reheating. Using a minimal particle physics model, and a general parametrization of the inflaton energy density and the evolution of the Standard Model temperature, we explore the conditions under which PTs occur and determine the corresponding PT parameters (the PT temperature, duration and strength), which depend on the evolution of the background during reheating. We find that, in certain cosmological scenarios, PTs can be delayed and prolonged compared to the standard post-inflationary evolution. Incorporating these PT parameters, we compute the resulting GW spectrum generated from the various processes occurring during a first-order PT. We find that, in comparison to the standard cosmological history, the GW amplitude and peak frequency can be modified by several orders of magnitude due to the cosmological evolution during reheating. In particular, the GW spectra could be within the reach of next-generation GW observatories.

    ↳ astro-ph.COhep-phPRD(2026)·8 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.