Wed·Jan 14, 2026Wednesday·January 14, 2026

1. 01*

   Insights into Meson and Baryon Structure using Continuum Schwinger Function Methods

   Daniele Binosi🇮🇹 · Craig D. Roberts🇨🇳 · Zhao-Qian Yao🇩🇪

   The bulk of visible mass is supposed to emerge from nonperturbative dynamics within quantum chromodynamics (QCD). Following years of development and refinement, continuum and lattice Schwinger function methods have recently joined in revealing the three pillars that support this emergent hadron mass (EHM); namely, a nonzero gluon mass-scale, a process-independent effective charge, and dressed-quarks with running masses that take constituent-like values at infrared momenta. One may argue that EHM and confinement are inextricably linked; and theory is now working to expose their manifold expressions in hadron observables and highlight the types of measurements that can be made in order to validate the paradigm. This contribution sketches these ideas via the unified explanation of pion and proton electromagnetic and gravitational form factors.

   hep-phhep-exhep-latnucl-ex+1J.Subatomic Part.Cosmol.(2026)·1 citation
2. 02*

   Lepton Magnetic Moments: What They Tell Us

   Fred Jegerlehner🇩🇪

   Recently, the exciting new Fermilab (FNAL) Muon g-2 measurement impressively confirmed the final Brookhaven (BNL) result from 2004, and with a result four times more precise, has launched a new serious attack on the Standard Model (SM). On the theoretical side, ab initio lattice QCD (LQCD) calculations of hadronic vacuum polarization have made remarkable progress. They are now the new standard for studying the leading non-perturbative contributions, which have previously hindered matching with the precision required for full exploitation of the experimental results. The lattice results affected both leading hadronic contributions the hadronic vacuum polarization (HVP) and the hadronic light-by-light (HLbL) contributions by increasing the previously generally accepted $e^{+}{e}^{-}$ to hadrons based dispersion relation results. The shifts reduced the discrepancy between theory and experiment, leaving nothing missing. One of the most prominent signs of Beyond the Standard Model (BSM) physics has disappeared: the SM appears validated more than ever, in agreement with what other searches at the Large Hadron Collider (LHC) at CERN tell us! A triumph of the SM, even though the SM cannot explain known cosmological puzzles like dark matter or baryogenesis, and why neutrino masses are so tiny, the absence of strong CP violation, for example. I also argue that the discrepancy between the data-driven dispersive result and the lattice QCD results for the hadronic vacuum polarization can be largely explained by correcting the $e^{+}{e}^{-}$ data for 'rho-gamma' mixing effects.

   hep-phActa Phys.Polon.Supp.(2026)·0 citations
3. 03*

   Energy and momentum dependence of the soft-axion interaction rate

   Killian Bouzoud🇫🇷 · Jacopo Ghiglieri🇫🇷 · M. Laine🇨🇭 · G.S.S. Sakoda🇧🇷

   Axions coupled to thermal non-Abelian gauge fields may have cosmological significance. As the heat bath defines a frame, its influence depends separately on energy and momentum. A light-like momentum ($k\approx \omega$) is relevant for the axion contribution to the effective number of light neutrinos, $\Delta N_{\mathrm{eff}}^{}$, whereas a vanishing momentum ($k=0$) plays a role for warm natural inflation or ultralight dark matter, and has been employed in lattice estimates (both classical and quantum-statistical) of the strong sphaleron rate. Focussing on soft energies (${\alpha }_{\mathrm{s}}^{}T\ll \omega \ll \pi T$), we carry out an HTL computation to show how the domains $k=0$ and $k\approx \omega$ interpolate to each other. We then compare with lattice data at $k=0$, and connect our analysis to NLO computations at $k\approx \omega \ge \pi T$. Assembling the current best input, we re-investigate light QCD axion decoupling dynamics at $T\ge 200$ MeV, showing that efficient interactions in the ultrasoft domain increase $\Delta N_{\mathrm{eff}}^{}$ from $\sim 0.03$ to $\sim 0.04$ at $f_a^{}=4\times 10_{}^8$ GeV.

   hep-phJHEP(2026)·6 citations
4. 04*

   Study of $CP$ violation in ${\Lambda }_b^0/{\Xi }_b^{-}\to \Lambda (1520)M$ decays with the final-state rescattering mechanism

   Tian-Liang Feng🇨🇳 · Hui-Qiang Shang🇨🇳 · Jing Gao🇩🇪 · Qin Qin🇨🇳 · Fu-Sheng Yu🇨🇳

   Recently, the LHCb collaboration reported the first observation of $CP$ violation in baryon decays, with a significance of more than $5\sigma$. This strongly motivates us to investigate the $CP$ violation in more baryon decay processes. In this work, we employ the final-state rescattering mechanism with introducing two model parameters, ${\Lambda }_{charm}$ and ${\Lambda }_{charmless}$, and calculate two-body non-leptonic baryon decays ${\Lambda }_b^0\to \Lambda (1520){\pi }^0/\kappa (700)/f_0(500,980)/{\rho }^0/K^{\ast 0}/\varphi$ and ${\Xi }_b^{-}\to \Lambda (1520)K^{-}$. Consequently, we evaluate the corresponding branching ratios, $CP$ asymmetries, and interference effects between different decay amplitudes. Our theoretical predictions for certain decay channels are in good agreement with current experimental measurements, while the remaining processes--particularly the remarkably large $CP$ violation observable revealed by the kinematic analysis are expected to be tested in future experiments.

   hep-ph3 citations
5. 05*

   Geometric Constraint on Residue Phases: Resolving the N(2190) Anomaly and Diagnosing Exotic States

   S. Ceci🇭🇷 · R. Omerović🇧🇦 · H. Osmanović🇧🇦 · M. Uroić🇭🇷 · M. Vukšić🇬🇧 · B. Zauner🇭🇷

   We derive a parameter-free geometric constraint on residue phases dictated by the pole-threshold angle. Using the N(2190) anomaly as a test case, this constraint reveals a sign ambiguity in prior data; correcting it yields a phase of $-28^{\circ }\pm 10^{\circ }$, matching our prediction. This consistency validates the method as a model-independent diagnostic for distinguishing compact from molecular states, offering a rigorous tool for exotic spectroscopy.

   hep-phPLB(2026)·4 citations
6. 06*

   Decoding the Amplitude Pair with Distinct CPV Phases in Charmed Baryon Decays

   Zhi-Peng Xing🇨🇳 · Jin Sun🇰🇷 · Xiao-Gang He🇨🇳

   In this Letter, we propose a strategy to extract information on the hierarchical amplitude pair in singly Cabibbo-suppressed (SCS) charmed baryon two-body decays, with a dominant amplitude proportional to ${\lambda }_s=V_{cs}^{\ast }{V}_{us}$ from tree operators and sub-leading one proportional to ${\lambda }_b=V_{cb}^{\ast }{V}_{ub}$ from both penguin and tree contributions. The coexistence of these two amplitudes is essential for generating nonzero CP violation (CPV) effects. Since the ${\lambda }_b$ amplitude is strongly suppressed, its experimental determination is highly challenging. However, by exploiting SU(3) flavor symmetry, which relates the well-measured Cabibbo-favored (CF) amplitudes to the SCS tree amplitudes, information on the ${\lambda }_b$ amplitude can be extracted. Using current experimental data, a conservative analysis yields ${\lambda }_b$ amplitudes can be as large as about $10\%$ of the corresponding tree amplitudes with a significance of $2.1\sigma$. In addition, the Lee-Yang parameters of these decays provide an independent probe of this elusive term. We further identify two golden decay channels, ${\Xi }_c^0\to p{K}^{-}$ and ${\Xi }_c^0\to {\Sigma }^{+}{\pi }^{-}$, which are particularly well suited for experimental studies of CPV.

   hep-phhep-ex1 citation
7. 07*

   Where to find $X(17)$?

   Jun Jiang🇨🇳 · Cong-Feng Qiao🇨🇳 · Yu-Han Zhao🇨🇳

   The Atomki anomaly puts forward the hypothesis of an $X(17)$ particle to explain its observation. Utilizing experimental results from the Atomki experiments, measurements of the electron's anomalous magnetic moment, beam dump experiments, the KLOE-2 experiment, the PADME experiment, and the parity-violating Møller scattering experiment, we derive constraints on the $Xee$ coupling of the $X(17)$ boson to electrons. It is found that the scalar and pseudoscalar models can be excluded by Atomki experiments due to the parity conservation, and the pure axial-vector model is excluded at 98\% C.L. Meanwhile, the analyses in both pure vector and the vector $\pm$ axial-vector models consistently show that the $Xee$ coupling is of the vector type and has an almost fixed value, $\left(6.78\pm 0.042\right)\times 10^{-4}\lesssim |{\epsilon }_e^v|\lesssim \left(6.93\pm 1.66\right)\times 10^{-4}$ in unit of electric charge $e$.

   hep-ph1 citation
8. 08*

   Phenomenological Study of ${\Omega }_c\to {\Omega }^{-}{\pi }^{+}$ at Polarized Electron-Positron Collider

   Yunlu Wang🇨🇳 · Yunlong Xiao🇨🇳 · Pengcheng Hong🇨🇳

   The exploration of symmetry laws stands as a cutting-edge direction in modern physics research. This work delves into the examination of P and CP symmetry properties within the charm quark system by analyzing asymmetry parameters in the two-body decay process of ${\Omega }_c$. By accounting for the polarization effects of electron and positron beams and employing the helicity formalism, we systematically analyze the decay characteristics of ${\Omega }_c$ and its subsequent hyperon decays through specific asymmetry parameters. A comprehensive formulation of the angular distribution for these decay processes has been developed. The research assesses the detection sensitivity of asymmetry parameters in the ${\Omega }_c\to {\Omega }^{-}{\pi }^{+}$ decay mode across different experimental conditions, including varying data sample sizes and beam polarization configurations. These results contribute to enriching a theoretical foundation for forthcoming experimental endeavors at the STCF, offering significant implications for symmetry studies in the charm sector.

   hep-phCPC(2026)·0 citations
9. 09*

   An Optimal Observable Machine for reinterpretable measurements in high-energy physics

   Torben Mohr🇩🇪 · Alejandro Quiroga Triviño🇩🇪 · Fabian Riemer🇩🇪 · Artur Monsch🇩🇪 · Matteo Defranchis🇨🇭 · Joscha Knolle🇩🇪 · Ankita Mehta🇨🇭 · Jan Kieseler🇩🇪 · Markus Klute🇩🇪

   A machine-learning-based framework for constructing generator-level observables optimized for parameter extraction in particle physics analyses is introduced, referred to as the Optimal Observable Machine (OOM). Unfoldable differential distributions are learned that maximize sensitivity to a parameter of interest while remaining robust against detector effects, systematic uncertainties, and biases introduced by the unfolding procedure. Detector response and systematic uncertainties are explicitly incorporated into the training through a likelihood-based loss function, enabling a direct optimization of the expected measurement precision while minimizing the bias from any assumption on the parameter of interest itself. The approach is demonstrated in an application to top quark physics, focusing on the measurement of a recently observed pseudoscalar excess at the top quark pair production threshold in dilepton final states. It is shown that a generator-level observable with enhanced sensitivity and long-term reinterpretability can be constructed using this method.

   hep-phhep-ex0 citations
10. 10*

    Differential observables for the Higgs-strahlung process to all orders in EFT

    Sourav Bera · Debsubhra Chakraborty🇮🇳 · Susobhan Chattopadhyay🇮🇳 · Rick S. Gupta🇮🇳

    We develop methods to obtain the fully differential cross-section for the $f\bar{f}\to Z(\ell \ell )h$ process to any desired order in effective field theory (EFT). To achieve this, we first derive a mapping between the partial wave expansion and the EFT expansion to all orders. We find that at lower orders, EFT predicts correlations between the different partial wave coefficients. This allows us to construct linear combinations of partial wave coefficients that get their leading contributions from a higher dimension EFT operator. We then introduce experimental observables, the so called angular moments -- that probe these linear combinations of partial wave coefficients -- and can be determined from a fully differential analysis of the angular distribution of the leptons arising from the $Z$ decay. We show that analysing the dependence of these angular moments on the $Zh$ invariant mass allows us to systematically probe all higher dimension EFT operators contributing to this process. While we take the Higgs-strahlung process as an example, the methods developed here are completely general and can be applied to other 2-to-2 collider processes.

    hep-phhep-exhep-th1 citation
11. 11*

    Lattice-based equation of state with a critical point from constant entropy contours and its comparison to effective QCD approaches

    Hitansh Shah🇺🇸 · Mauricio Hippert🇧🇷 · Jorge Noronha🇺🇸 · Claudia Ratti🇺🇸 · Volodymyr Vovchenko🇺🇸

    In this work, we systematically assess the performance of a new method from [H. Shah et al., Phys. Rev. C 113, L012201] for locating the QCD critical point using constant-entropy contours by testing it against various effective QCD approaches. We demonstrate that, while the method yields spurious critical points in purely hadronic models (HRG) due to non-parabolic contour behavior at low temperatures ($T\lesssim 120$ MeV), it accurately reproduces the CP location in frameworks that feature a genuine phase transition and benchmarked against lattice QCD, such as Holographic Einstein-Maxwell-Dilaton, and Functional QCD approaches. Building on our previous determination of constant entropy contours using lattice data, we extend that analysis to construct a complete Lattice-based Equation of State (EoS) at finite density, which features a critical point at $(T,{\mu }_B)\approx (114,602)$ MeV. By integrating the extrapolated entropy density with respect to temperature, we reconstruct the pressure, baryon density, susceptibility, and speed of sound in the critical region, and analyze the focusing behavior of isentropic trajectories in the vicinity of the critical point.

    hep-phnucl-thPRD(2026)·3 citations
12. 12*

    The Quantum Complexity of String Breaking in the Schwinger Model

    Sebastian Grieninger🇺🇸 · Martin J. Savage🇺🇸 · Nikita A. Zemlevskiy🇺🇸

    String breaking, the process by which flux tubes fragment into hadronic states, is a hallmark of confinement in strongly-interacting quantum field theories. A suite of quantum complexity measures is examined using Matrix Product States to characterize the string breaking process in the 1+1D Schwinger model. We demonstrate the presence of nonlocal quantum correlations along the string that may affect fragmentation dynamics, and show that entanglement and magic offer complementary perspectives on string formation and breaking beyond conventional observables.

    hep-phhep-lathep-thnucl-th+123 citations
13. 13*

    Particle mixing and quantum reference frames

    Antonio Capolupo🇮🇹 · Gabriele Pisacane🇮🇹 · Aniello Quaranta🇮🇹

    We discuss the role of quantum reference frames in providing a viable definition of rest frame for mixed particles. We then analyze the related concept of frame-dependent entanglement and its impact on the phenomenology of neutral mesons and neutrinos.

    hep-ph0 citations
14. 14*

    Lorentz and CPT Tests in Neutron and Storage-Ring EDM Experiments

    Yunhua Ding🇺🇸

    We investigate Lorentz- and CPT-violating effects in neutron and storage-ring electric dipole moment (EDM) experiments within the framework of the Standard-Model Extension (SME). For neutron EDM experiments, perturbation theory is applied to derive leading-order contributions to the spin precession frequency arising from Lorentz and CPT violation. For storage-ring experiments, a generalized Bargmann-Michel-Telegdi equation is used to determine the corresponding spin-precession modifications. The analysis establishes explicit correspondences between measured EDMs and specific SME coefficients, providing a basis for setting the first limits on several previously unconstrained coefficients for Lorentz violation in future studies.

    hep-ph1 citation
15. 15*

    Dark Matter emission at Belle II and NA62 in Minimal Flavor Violation framework

    Federico Mescia🇮🇹 · Shohei Okawa🇰🇷 · Joel Swallow🇨🇭 · Claudio Toni🇫🇷

    Minimal Flavor Violation (MFV) provides a compelling framework for exploring physics beyond the Standard Model, in which new QCD-singlet fields transforming under the global $\mathrm{SU}(3{)}^3$ quark flavor symmetry can naturally be stable and act as dark matter (DM) candidates. We show that the DM-MFV framework naturally accommodates the excess in either $K^{+}\to {\pi }^{+}\nu \bar{\nu }$ or $B^{+}\to K^{+}\nu \bar{\nu }$, while a unified explanation of both channels simultaneously cannot be achieved within a minimal setup containing only a single dark matter multiplet with nearly degenerate masses. Overall, our findings underscore the intricate interplay between MFV-based model building, flavored dark matter scenarios, and precision flavor experiments, highlighting flavored dark matter as a framework that is both theoretically robust and experimentally testable.

    hep-phhep-exPRD(2026)·1 citation
16. 16*

    Merging multidimensional equations of state of strongly interacting matter via a statistical mixture

    Yumu Yang🇺🇸 · Prachi Garella🇺🇸 · Musa R. Khan🇺🇸 · Tulio E. Restrepo🇺🇸 · Joaquin Grefa🇺🇸 · Johannes Jahan🇺🇸 · Mauricio Hippert🇧🇷 · Jorge Noronha🇺🇸 · Claudia Ratti🇺🇸 · Romulo Rougemont🇧🇷

    We introduce a general method to merge multidimensional equations of state (EoSs) by combining them in a two-fluid equilibrium statistical mixture in the grand canonical ensemble. The merged grand potential density $\omega$ is built directly from the input EoSs and the fluid fractions are fixed by minimizing $\omega$ at fixed temperature $T$ and baryon chemical potential ${\mu }_B$. Thermodynamic consistency and stability are guaranteed as all thermodynamic quantities are consistently derived from a single merged grand potential $\omega (T,{\mu }_B)$ with the correct convexity properties. Our method can accommodate a first-order phase transition and a critical endpoint with mean-field critical exponents. We use this method to merge a van der Waals Hadron-Resonance-Gas EoS with a holographic Einstein-Maxwell-Dilaton EoS that has a critical point and a first-order line. The result is a single EoS, spanning hadronic and deconfined matter over a broad range in $(T,{\mu }_B)$, which can be readily used in heavy-ion hydrodynamic simulations. Our merging method can be generalized to consider a higher dimensional phase diagram (e.g., by considering more chemical potentials) and more than two input EoSs.

    ↳ nucl-thhep-lathep-phPRD(2026)·9 citations
17. 17*

    Excluding Hypothetical Light Boson Interpretation of Yb King Plot Nonlinearity with the ${}^1{S}_0\leftrightarrow {}^3{P}_2$ Isotope Shift Measurement

    Taiki Ishiyama · Koki Ono · Reiji Asano · Hokuto Kawase · Tetsushi Takano · Ayaki Sunaga · Yasuhiro Yamamoto · Minoru Tanaka · Yoshiro Takahashi

    We present precision spectroscopy and isotope shift measurement of the ${}^1{S}_0\leftrightarrow {}^3{P}_2$ clock transition in neutral ytterbium ($\mathrm{Yb}$) atoms. By revealing a magic wavelength at $905.4(2)$ nm, we successfully achieve the atomic spectrum narrower than $100$ Hz. The interleaved clock operation between isotopes allows us to determine isotope shifts of four bosonic isotope pairs at Hz-level uncertainties, which is combined with those of other four ultra-narrow transitions in $\mathrm{Yb}$ and ${\mathrm{Yb}}^{+}$ to construct the King plot. Importantly, the new isotope shift data reported in this work is a key to exclude the possibility of attributing the observed nonlinearity of the three-dimensional King plot solely to the new physics, while the previous works rely on the other terrestrial bound set by the neutron scattering and $(g-2{)}_e$ measurements. This work paves the way for the effective use of precision isotope shift data in the King plot analysis and stimulates further measurements in $\mathrm{Yb}$ and other elements.

    ↳ physics.atom-phhep-exhep-phnucl-ex1 citation
18. 18*

    Primordial Gravitational Waves from Scalar Backreaction in Axion-SU(2) Inflation

    Mattia Cielo🇮🇹 · Ema Dimastrogiovanni🇳🇱 · Matteo Fasiello🇪🇸 · Alexandros Papageorgiou🇪🇸

    In this work, we perform the first numerical study of strong scalar backreaction in spectator chromo-natural inflation (SCNI) in the case where the spectator sector decays during inflation. The tachyonic instability in scalar fluctuations, activated as the system crosses the $m_Q=\sqrt{2}$ threshold, amplifies perturbations and may significantly alter the background dynamics. The strong scalar backreaction regime introduces an effective quartic term in the potential for the gauge field background that rapidly drives it to zero, accelerating the axion-gauge system decay. We describe the dynamics of such decay and derive the gravitational wave spectrum for a set of benchmark parameters. Interestingly, the signal may peak at interferometer scales and lie within LISA's projected sensitivity.

    ↳ astro-ph.COhep-phPRD(2026)·1 citation
19. 19*

    On equivalent methods for functional determinants

    Matthias Carosi🇩🇪

    Computing functional determinants of differential operators is central to any field-theoretical calculation relying on a saddle-point expansion. A variety of approaches is available for the computation that avoid having to know the eigenspectrum of the operator, and in particular the Gel'fand-Yaglom theorem and the Green's function method. In this note, we show how both approaches can be constructed using a contour integral argument and conclude that these are completely equivalent for computing ratios of determinants of one-dimensional operators. Furthermore, we comment on the presence of vanishing as well as negative eigenvalues and show how the Green's function method provides a natural prescription for handling them.

    ↳ hep-thhep-phmath-phmath.MP+1JHEP(2026)·3 citations
20. 20*

    QCD phase-transition under the light of Thermofractal

    Airton Deppman🇧🇷

    The deconfining transition in $SU(3)$ gauge theory, traditionally interpreted through the Gross-Witten-Wadia (GWW) model as a sharp third-order phase transition in the large-$N_c$ limit, appears as a smooth crossover in lattice QCD. This work demonstrates that the transition is topologically smoothed into a crossover by incorporating the fractal momentum space structure inherent to thermofractals. By matching the non-extensive $\beta$-function to one-loop QCD results, a fundamental scaling of the thermofractal index $q$ is derived as a function of the number of flavours $N_f$. It is proven that applying a $q$-deformed derivative operator ${\mathcal{D}}_q$ to the $q$-logarithm of the eigenvalue distance results in a non-extensive measure that effectively smears the topological stiffness of the gauge vacuum. A unified master equation for the Polyakov loop $⟨L⟩$ is presented, governed by the thermofractal index $q$ and a single variance parameter ${\sigma }^2(T)$ that scales as $T^{1/(q-1)}$. The observed phase dynamics are shown to be asymptotic limits of this unified density: a ``soft'' algebraic growth $⟨L⟩\propto T^{11}$ in the 1D string-like confined regime for $N_f=0$, and a rapid $1-⟨L⟩\propto T^{-21}$ suppression in the 3D deconfined volume for $N_f=3$. This approach provides a microscopic foundation for partial deconfinement theory and reproduces lattice QCD data with a reduced ${\chi }^2\approx 1.12$, offering a rigorous reconciliation between matrix model topology and the continuous QCD crossover.

    ↳ hep-lathep-exhep-phhep-th0 citations
21. 21*

    Search for Cosmic Ray Electron Boosted Dark Matter with the CDEX-10 Experiment

    R. Xu🇨🇳 · 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🇨🇳 · J. Y. Cui🇨🇳 and 76 other authors

    We present new constraints on the cosmic ray electron boosted light dark matter (CReDM) using the 205.4 kg$\cdot$day data of the CDEX-10 experiment located at the China Jinping Underground Laboratory. The cosmic ray electron spectrum and distribution in the Galaxy are generated by the $\mathtt{GALPROP}$ code package. In the calculation process of DM-electron scattering process in the Galaxy, we consider the energy-dependency of the DM-electron scattering cross section. The constraints on CReDM are set for both heavy and light mediator scenarios using the CDEX-10 dataset. The result exceeds previous Standard Halo Model (SHM) limits for DM mass lower than 0.6 MeV in heavy mediator case and corresponds to the best sensitivity among all direct detection experiments from 1 keV to 0.5 MeV in the light mediator scenario.

    ↳ hep-exhep-phphysics.ins-det1 citation
22. 22*

    Note on pulsar timing array correlation functions induced by peculiar velocities

    Neha Anil Kumar🇺🇸 · Keisuke Inomata🇺🇸 · Marc Kamionkowski🇺🇸

    Several papers have recently calculated the contribution to pulsar timing array overlap reduction functions (ORFs) induced by our peculiar velocity with respect to the rest frame of the stochastic gravitational-wave background. Here we show that a harmonic-space calculation confirms the most recent result. We note that, with the harmonic-space calculation, the ORFs for spin-1 GWs and the correlations with astrometry measurements are also easily obtained.

    ↳ astro-ph.COgr-qchep-ph0 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.