Fri·May 20, 2022Friday·May 20, 2022

1. 01*

   ALP one-loop corrections and nonresonant searches

   Jesús Bonilla🇪🇸

   We consider the complete leading-order -- dimension five -- effective linear Lagrangian for ALPs. The full set of one-loop contributions to ALP-SM effective couplings are derived, including all finite corrections. A few phenomenological consequences of these computations are also explored as illustration, with flavour diagonal channels in the case of fermions: in particular, we explore one-loop constraints on the coupling of the ALP to top quarks. Additionally, we propose a new search for ALPs, targeting VBS processes at the LHC. For this, we consider the tree-level diboson production in VBS, where the ALP participates as an off-shell mediator. Upper limits on ALP EW couplings are obtained from a reinterpretation of Run 2 public CMS VBS analyses. Simple projections for LHC Run 3 and HL-LHC are also calculated, demonstrating the power of future dedicated analyses at ATLAS and CMS.

   hep-ph1 citation
2. 02*

   Heavy-quark production at NNLO

   Simone Devoto🇮🇹

   We present the calculation of QCD radiative corrections to heavy-quark production at NNLO. The calculation is implemented in an updated version of \textsc{Matrix}, which allows us to obtain multidifferential predictions for stable top quarks. We also report on the NNLO calculation for $b\bar{b}$ production and comment on the inclusion of top-quark decays and of the extension of our results to $t\bar{t}H$.

   hep-ph0 citations
3. 03*

   Production of the ${\eta }_1(1855)$ through kaon induced reactions under the assumptions that it is a molecular or a hybrid state

   Xiao-Yun Wang🇨🇳 · Fan-Cong Zeng🇨🇳 · Xiang Liu🇨🇳

   By the reaction of kaon interacting with a proton, we investigate the production of the newly observed ${\eta }_1(1855)$ predicted in the picture of the $K{\bar{K}}_1(1400)$ molecular state and hybrid state. The total and differential cross sections of the concrete $K^{-}p\to {\eta }_1(1855)\Lambda$ reaction are calculated. Taking the partial decay width of the ${\eta }_1$ to $K{\bar{K}}^{\ast }$ as 0.9 MeV and 98.1 MeV, the minimum cross section of the ${\eta }_1(1855)$ production via the $K^{-}p$ reaction can reach up 0.59 $nb$ and 63.8 $nb$ at the center of mass energies $W\simeq 3.5$ GeV, respectively. The differential cross sections for the ${\eta }_1(1855)$ production at the different center of mass energies are also available. Furthermore, we present the Dalitz processes of $2\to 3$ and $2\to 4$, and initially discuss the feasibility of finding out the ${\eta }_1(1855)$ in experiments like J-PARC.

   hep-phPRD(2022)·23 citations
4. 04*

   Spin evolution of massive fermion in QED plasma

   Ziyue Wang🇨🇳

   The dynamical evolution of spin of a massive probe fermion in a massless hot QED plasma at local equilibrium is investigated through the quantum kinetic theory. We consider the massive probe fermion undergoing 2-by-2 Coulomb scattering with the massless fermions in the medium. The axial kinetic equation is derived including the collision terms to the first order of gradients and leading logarithmic order of the coupling. The collision terms are vanishing at global equilibrium, around which the relaxation time can be extracted as an operator. We further decompose the axial kinetic equation into kinetic equations of axial-charge density as well as the transverse magnetic dipole moment, and illustrate the diffusion and polarization effect through preliminary numerical analysis.

   hep-phPRD(2022)·23 citations
5. 05*

   Indirect Detection of Low-mass Dark Matter Through the ${\pi }^0$ and $\eta$ Windows

   J. G. Christy🇺🇸 · Jason Kumar🇺🇸 · Arvind Rajaraman🇺🇸

   We consider the search for gamma-rays produced by the annihilation or decay of low-mass dark matter which couples to quarks. In this scenario, most of the photons are produced from the decays of ${\pi }^0$ or $\eta$ mesons. These decays produce distinctly different photon signatures due to the difference in meson mass. We assess the ability of the future MeV-range observatories to constrain the hadronic final states produced by dark matter annihilation or decay from the shape of the resulting photon spectrum. We then comment on how this information can be used to determine properties of the dark matter coupling to the quark current, based on the approximate symmetries of low-energy QCD.

   hep-phastro-ph.COastro-ph.HEPRD(2022)·4 citations
6. 06*

   Off-shell probes of the Higgs Yukawa couplings: light quarks and charm

   Natascia Vignaroli🇮🇹

   We review the present status and the future prospects for the measurements of the Higgs Yukawa couplings to light quarks and charm. A special focus is given to novel proposed off-shell probes, which offer promising and complementary opportunities to test light quark Yukawas in triboson final states. Additionally, a new off-shell strategy to test the charm Yukawa coupling in the final state with two bosons plus a charm and a jet is considered. First estimates for the HL-LHC and the FCC-hh sensitivities on the channel are presented, showing encouraging results.

   hep-phhep-exSymmetry(2022)·15 citations
7. 07*

   Impact of the Dresden-II and COHERENT neutrino scattering data on neutrino electromagnetic properties and electroweak physics

   M. Atzori Corona🇮🇹 · M. Cadeddu🇮🇹 · N. Cargioli🇮🇹 · F. Dordei🇮🇹 · C. Giunti🇮🇹 · Y.F. Li🇨🇳 · C. A. Ternes🇮🇹 · Y.Y. Zhang🇨🇳

   Coherent elastic neutrino-nucleus scattering (CE$\nu$NS) represents a powerful tool to investigate key electroweak physics parameters and neutrino properties since its first observation in 2017 by the COHERENT experiment exploiting the spallation neutron source at Oak Ridge National Laboratory. In light of the recent detection of such a process with antineutrinos produced by the Dresden-II reactor scattering off a germanium detector, we revisit the limits so far set on the neutrino magnetic moments, charge radii and millicharges as well as on the weak mixing angle. In order to do so, we also include the contribution of elastic neutrino-electron scattering, whose effect becomes non negligible in some beyond the Standard Model theories. By using different hypotheses for the germanium quenching factor and the reactor antineutrino flux, we provide a measurement of the weak mixing angle at the low-energy scale of the Dresden-II reactor experiment and, thanks to a combined analysis with the latest cesium iodide and argon data set released by the COHERENT Collaboration, we deliver updated limits for the neutrino electromagnetic properties. Interestingly, we are able to set a new best upper limit on the electron neutrino charge radius and significantly improve the other CE$\nu$NS-related limits on the neutrino electric charge and magnetic moment.

   hep-phhep-exnucl-exnucl-thJHEP(2022)·81 citations
8. 08*

   Supersymmetric minimal $U(1{)}_X$ model at the TeV scale with right-handed Majorana neutrino dark matter

   Nobuchika Okada🇺🇸 · Desmond Villalba🇺🇸

   We propose a supersymmetric extension of the minimal $U(1{)}_X$ model, along with a new $Z_2$-parity. One of the salient features of this model relates to how both the $U(1{)}_X$ gauge symmetry and R-parity are broken radiatively at the TeV scale by the VEV of a $Z_2$-even right handed neutrino. By assigning one right-handed neutrino $Z_2$-odd parity, it can remain a viable dark matter (DM) candidate, despite R-parity being broken. Furthermore, the DM relic abundance receives an enhanced annihilation cross section due to the $U(1{)}_X$ gauge boson ($Z^{\prime }$) resonance and is in agreement with the current observations. We have also found a complementarity that exists between the observed DM relic abundance and search results for the $Z^{\prime }$ boson resonance at the Large Hadron Collider (LHC), which further constrains the parameter space of our $U(1{)}_X$ model. Lastly, we consider a $SU(5)\times U(1{)}_x$ GUT extension and investigate the complementarities mentioned previously.

   hep-phPRD(2023)·1 citation
9. 09*

   Hybrid kT-factorization and impact factors at NLO

   Andreas van Hameren🇵🇱 · Leszek Motyka🇵🇱 · Grzegorz Ziarko🇵🇱

   In the hybrid kT-factorization formula, one initial-state parton momentum is space-like and carries non-vanishing transverse components, while the other is on-shell. We promote this factorization formula to next-to-leading order. Studying the partonic cross section, we identify all soft and collinear divergencies in the real and virtual contribution, and recognize that all non-cancelling ones can be attributed to PDF evolution, evolution kernel, and target impact factors. In result, we construct a framework that may be used to compute NLO impact factors in general. In particular, we recover known expressions for inclusive NLO quark-and gluon impact factor corrections.

   hep-phJHEP(2022)·45 citations
10. 10*

    Neutrino capture on tritium as a probe of flavor vacuum condensate and dark matter

    Antonio Capolupo🇮🇹 · Aniello Quaranta🇮🇹

    We show that the study of neutrino capture on tritium, for non-relativistic neutrinos, can allow to distinguish among the various neutrino models, eventually prove the quantum field theory condensation effects and permit to test the hypothesis according to which the flavor vacuum energy gives a contribution to the dark matter of the universe. Indeed, we show that the capture rate depends on the neutrino model considered, and that it brings an imprint of the flavor vacuum condensate. Experiments like PTOLEMY, designed to reveal the cosmic neutrino background, then can give an indication of the existence of the dark matter component induced by neutrino mixing.

    hep-phPLB(2023)·31 citations
11. 11*

    A short overview on low mass scalars at future lepton colliders

    Tania Robens🇭🇷

    In this manuscript, I give a short summary on scenarios with new physics scalars that could be investigated at future $e^{+}{e}^{-}$ colliders. I concentrate on cases where at least one of the additional scalar has a mass below 125 GeV, and discuss both models where this could be realized, as well as studies which focus on such scenarios. This work is based on several overview talks I recently gave at the CEPC workshop, FCC week and ECFA future collider workshop, as well as a Snowmass White Paper.

    hep-phUniverse(2022)·23 citations
12. 12*

    Semileptonic B decays matrix elements

    Guido Martinelli🇮🇹 · Manuel Naviglio🇮🇹 · Silvano Simula🇮🇹 · Ludovico Vittorio🇮🇹

    We present some applications of the unitarity-based Dispersion Matrix (DM) approach to the extraction of the CKM matrix element $|V_{cb}|$ from the experimental data on the exclusive $B_{(s)}\to D_{(s)}^{(\ast )}\ell {\nu }_{\ell }$ decays. The DM method allows to achieve a non-perturbative, model-independent determination of the momentum dependence of the semileptonic form factors. Starting from lattice results available at large values of the 4-momentum transfer and implementing non-perturbative unitarity bounds, the behaviour of the form factors in their whole kinematical range is obtained without introducing any explicit parameterization of their momentum dependence. We firstly illustrate the effectiveness of the method by considering the case of the semileptonic $B\to \pi$ decay, which is a good benchmark since the kinematic range is large. Then, we focus on the four exclusive semileptonic $B_{(s)}\to D_{(s)}^{(\ast )}\ell {\nu }_{\ell }$ decays and we extract $|V_{cb}|$ from the experimental data for each transition. The average over the four channels is $|V_{cb}|=(41.2\pm 0.8)\cdot 10^{-3}$. We find, for the first time, an exclusive value which is compatible with the latest inclusive determination at $1\sigma$ level. We address also the issue of Lepton Flavour Universality by computing pure theoretical estimates of the $\tau /\ell$ ratios of the branching fractions for each channel. In the case of a light spectator quark we obtain $R(D^{\ast })=0.275(8)$ and $R(D)=0.296(8)$, which are compatible with the corresponding experimental values within $1.3\sigma$. In the case of a strange spectator quark we obtain $\text{R}(D_s^{\ast })=0.2497(60)$ and $\text{R}(D_s)=0.298(5)$.

    hep-phhep-exhep-lat2 citations
13. 13*

    Detector Requirements for Model-Independent Measurements of Ultrahigh Energy Neutrino Cross Sections

    Ivan Esteban🇺🇸 · Steven Prohira🇺🇸 · John F. Beacom🇺🇸

    The ultrahigh energy range of neutrino physics (above $\sim 10^7\mathrm{GeV}$), as yet devoid of detections, is an open landscape with challenges to be met and discoveries to be made. Neutrino-nucleon cross sections in that range - with center-of-momentum energies $\sqrt{s}\gtrsim 4\mathrm{TeV}$ - are powerful probes of unexplored phenomena. We present a simple and accurate model-independent framework to evaluate how well these cross sections can be measured for an unknown flux and generic detectors. We also demonstrate how to characterize and compare detector sensitivity. We show that cross sections can be measured to ${\simeq }_{-30}^{+65}$% precision over $\sqrt{s}\simeq$ 4-140 TeV ($E_{\nu }=10^7$-$10^{10}$ GeV) with modest energy and angular resolution and $\simeq 10$ events per energy decade. Many allowed novel-physics models (extra dimensions, leptoquarks, etc.) produce much larger effects. In the distant future, with $\simeq 100$ events at the highest energies, the precision would be $\simeq 15\%$, probing even QCD saturation effects.

    hep-phastro-ph.HEhep-exPRD(2022)·30 citations
14. 14*

    Parametric resonance in neutrino oscillations induced by ultra-light dark matter and implications for KamLAND and JUNO

    Marta Losada🇦🇪 · Yosef Nir🇮🇱 · Gilad Perez🇮🇱 · Inbar Savoray🇮🇱 · Yogev Shpilman🇮🇱

    If ultra-light dark matter (ULDM) exists and couples to neutrinos, the neutrino oscillation probability might be significantly altered by a parametric resonance. This resonance can occur if the typical frequency of neutrino flavor-oscillations $\Delta m^2/(2E)$, where $\Delta m^2$ is the mass-squared difference of the neutrinos and $E$ is the neutrino energy, matches the oscillation frequency of the ULDM field, determined by its mass, $m_{\varphi }$. The resonance could lead to observable effects even if the ULDM coupling is very small, and even if its typical oscillation period, given by ${\tau }_{\varphi }=2\pi /m_{\varphi }$, is much shorter than the experimental temporal resolution. Defining a small parameter ${ϵ}_{\varphi }$ to be the ratio between the contribution of the ULDM field to the neutrino mass and the vacuum value of the neutrino mass, the impact of the resonance is particularly significant if ${ϵ}_{\varphi }{m}_{\varphi }L\gtrsim 4$, where $L$ is the distance between the neutrino source and the detector. Such parametric resonance can improve the fit to the KamLAND experiment measurements by about $3.5\sigma$ compared to standard oscillations. This scenario will be tested by the JUNO experiment.

    hep-phhep-exJHEP(2023)·26 citations
15. 15*

    Atmospheric resonant production for light dark sectors

    Luc Darmé🇫🇷

    Cosmic ray atmospheric showers provide an effective environment for the production of MeV-scale dark sector particles. We show that, when available, the resonant annihilation of positrons from the shower on atmospheric electrons is the dominant production mechanism by more than an order of magnitude. We provide a quantitative example based on dark photon production and update existing constraints on a corresponding light dark matter model from kilotons neutrino experiments and xenon-based direct detection experiments.

    hep-phhep-exPRD(2022)·11 citations
16. 16*

    Constraints on sterile neutrino models from strong gravitational lensing, Milky Way satellites, and Lyman-$\alpha$ forest

    Ioana A. Zelko🇺🇸 · Tommaso Treu🇺🇸 · Kevork N. Abazajian🇺🇸 · Daniel Gilman🇨🇦 · Andrew J. Benson🇺🇸 · Simon Birrer🇺🇸 · Anna M. Nierenberg🇺🇸 · Alexander Kusenko🇺🇸

    The nature of dark matter is one of the most important unsolved questions in science. Some dark matter candidates do not have sufficient nongravitational interactions to be probed in laboratory or accelerator experiments. It is thus important to develop astrophysical probes which can constrain or lead to a discovery of such candidates. We illustrate this using state-of-the-art measurements of strong gravitationally-lensed quasars to constrain four of the most popular sterile neutrino models, and also report the constraints for other independent methods that are comparable in procedure. First, we derive effective relations to describe the correspondence between the mass of a thermal relic warm dark matter particle and the mass of sterile neutrinos produced via Higgs decay and GUT-scale scenarios, in terms of large-scale structure and galaxy formation astrophysical effects. Second, we show that sterile neutrinos produced through the Higgs decay mechanism are allowed only for mass $>26$ keV, and GUT-scale scenario $>5.3$ keV. Third, we show that the single sterile neutrino model produced through active neutrino oscillations is allowed for mass $>92$ keV, and the 3 sterile neutrino minimal standard model ($\nu$MSM) for mass $>16$ keV. These are the most stringent experimental limits on these models.

    hep-phastro-ph.COastro-ph.GAPRL(2022)·62 citations
17. 17*

    Probing Free Nucleons with (Anti)neutrinos

    R. Petti🇺🇸

    We discuss a method to study free protons and neutrons using $\nu (\bar{\nu })$-hydrogen (H) Charged Current (CC) inelastic interactions, together with various precision tests of the isospin (charge) symmetry using $\nu$ and $\bar{\nu }$ CC interactions on both H and nuclear targets. Probing free nucleons with (anti)neutrinos provides information about their partonic structure, as well as a crucial input for the modeling of $\nu (\bar{\nu })$-nucleus (A) interactions. Such measurements can also represent a tool to address some of the limitations of accelerator-based neutrino scattering experiments on nuclear targets, originating from the combined effect of the unknown (anti)neutrino energy and of the nuclear smearing. We also discuss a method to impose constraints on nuclear effects and calibrate the (anti)neutrino energy scale in $\nu (\bar{\nu })$-A interactions, which are two outstanding systematic uncertainties affecting present and future long-baseline neutrino experiments.

    hep-phPLB(2022)·11 citations
18. 18*

    At the heart of baryonic matter the ARBUZ model favored by recent hadron form factor data

    Egle Tomasi-Gustafsson🇫🇷 · Simone Pacetti🇮🇹

    Data on electromagnetic form factors of proton, neutron, and $\Lambda$ from annihilation and scattering reactions are collected and interpreted in the frame of a generalized picture of the internal structure of baryons which holds in space-like and time-like regions. It is shown that these data give an insight of the space structure of the baryon for distances one hundred times smaller than the baryon size and, in the time-like region, a vision of the time evolution of the hadronic matter for times up to $10^{-25}$~s, that is two orders of magnitude shorter than the time taken by the light to cross the volume of a proton. In the proposed interpretation, the electric form factor of the proton in the space-like region can not cross zero, but vanishes or stays very small, as an extrapolation of the data seems to show. In the time-like region specific structures appearing in the data give evidence of the dominance of the quark-diquark structure in a specific range of time of the evolution of the system.

    ↳ nucl-thhep-ph0 citations
19. 19*

    Effective field theory treatment of $\mathcal{N}=4$ supersymmetric Yang-Mills thermodynamics

    Ubaid Tantary🇺🇸 · Jens O. Andersen🇳🇴 · Qianqian Du🇺🇸 · Michael Strickland🇺🇸

    At finite temperature the free energy density of $\mathcal{N}=4$ supersymmetric Yang-Mills can be calculated using resummed perturbation theory through the order ${\lambda }^{5/2}$. Effective field theory methods provide a useful alternative approach to streamline these calculations. In this proceedings contribution, I review recent work with my collaborators where we used effective field theory methods to calculate the free energy density of $\mathcal{N}=4$ supersymmetric Yang-Mills in four spacetime dimensions through second order in the 't Hooft coupling $\lambda$. At this order the contributions to the free energy density come from the hard scale $T$ and the soft scale $\sqrt{\lambda }T$. The contribution from the scale $T$ enters through the coefficients in the effective Lagrangian obtained by dimensional reduction and the effects of the scale $gT$ can be calculated using perturbative methods in the effective theory.

    ↳ hep-thhep-ph1 citation
20. 20*

    Color dependence of the topological susceptibility in Yang-Mills theories

    Ed Bennett🇬🇧 · Deog Ki Hong🇰🇷 · Jong-Wan Lee🇰🇷 · C.-J. David Lin🇹🇼 · Biagio Lucini🇬🇧 · Maurizio Piai🇬🇧 · Davide Vadacchino🇬🇧

    For Yang-Mills theories in four dimensions, we propose to rescale the ratio between topological susceptibility and string tension squared in a universal way, dependent only on group factors. We apply this suggestion to $SU(N_c)$ and $Sp(N_c)$ groups, and compare lattice measurements performed by several independent collaborations. We show that the two sequences of (rescaled) numerical results in these two families of groups are compatible with each other. We hence perform a combined fit, and extrapolate to the common large-$N_c$ limit.

    ↳ hep-lathep-phhep-thPLB(2022)·36 citations
21. 21*

    Gauge Symmetry Breaking in Flux Compactification with Wilson-line Scalar Condensate

    Kento Akamatsu🇯🇵 · Takuya Hirose🇯🇵 · Nobuhito Maru🇯🇵

    We discuss the gauge symmetry breaking of six dimensional theories in flux compactification with a magnetic flux background and a constant vacuum expectation value (VEV) for the scalar fields, which are zero modes of extra spatial components of the gauge field. Although the effective potential for the scalar fields are known not to be generated classically and radiatively in a magnetic flux background only, the one-loop effective potential is shown to be generated by the effects of the non-zero constant VEV. As illustrations, we calculate the one-loop effective potential in SU(2) and SU(3) Yang-Mills theories. In both cases, we find that the potential minimum is located at non-zero VEV and the gauge symmetry breaking takes place.

    ↳ hep-thhep-phPRD(2022)·7 citations
22. 22*

    Role of non-gaussian quantum fluctuations in neutrino entanglement

    Denis Lacroix🇫🇷 · A. B. Balantekin🇺🇸 · Michael J. Cervia🇺🇸 · Amol V. Patwardhan🇺🇸 · Pooja Siwach🇺🇸

    The flavor evolution of neutrinos in environments with large neutrino number densities is an open problem at the nexus of astrophysics and neutrino flavor physics. Among the many unanswered questions pertaining to this problem, it remains to be determined whether neutrino-neutrino coherent scattering can give rise to nontrivial quantum entanglement among neutrinos, and whether this can affect the flavor evolution in a meaningful way. To gain further insight into this question, here we study a simple system of two interacting neutrino beams, and obtain the exact phase-space explored by this system using the Husimi quasi-probability distribution. We observe that the entanglement induced by the coupling leads to strong delocalization in phase-space with largely non-Gaussian quantum fluctuations. The link between the neutrino entanglement and quantum fluctuations is illustrated using the one- and two-neutrino entropy. In addition, we propose an approximate phase-space method to describe the interacting neutrinos problem, where the exact evolution is replaced by a set of independent mean-field evolutions with a statistical sampling of the initial conditions. The phase-space approach provides a simple and accurate method to describe the gross features of the neutrino entanglement problem. Applications are shown using time-independent and time-dependent Hamiltonians in the non-adiabatic regime.

    ↳ nucl-thhep-phquant-phPRD(2022)·51 citations
23. 23*

    Snowmass White Paper: Generalized Symmetries in Quantum Field Theory and Beyond

    Clay Cordova🇺🇸 · Thomas T. Dumitrescu🇺🇸 · Kenneth Intriligator🇺🇸 · Shu-Heng Shao🇺🇸

    Symmetry plays a central role in quantum field theory. Recent developments include symmetries that act on defects and other subsystems, and symmetries that are categorical rather than group-like. These generalized notions of symmetry allow for new kinds of anomalies that constrain dynamics. We review some transformative instances of these novel aspects of symmetry in quantum field theory, and give a broad-brush overview of recent applications.

    ↳ hep-thhep-ph315 citations
24. 24*

    Capture of primordial black holes in extrasolar systems

    Benjamin V. Lehmann🇺🇸 · Ava Webber🇺🇸 · Olivia G. Ross🇺🇸 · Stefano Profumo🇺🇸

    The vast datasets associated with extrasolar systems promise to offer sensitive probes of new physics in the near future. We consider the possibility that such systems may capture primordial black holes (PBHs) or other exotic compact objects, giving rise to unique observational signatures. We estimate the rate of captures by extrasolar systems, accounting for several distinct mechanisms. We find that the capture rate is negligible unless PBHs account for the entirety of dark matter in a narrow mass range just above the threshold of existing constraints from evaporation. In this scenario, luminous evaporating PBHs may be detectable by exoplanet searches.

    ↳ astro-ph.EPastro-ph.SRgr-qchep-phJCAP(2022)·11 citations
25. 25*

    An analysis of the spin density matrix of quarkonium in heavy ion collisions

    Kayman J. Gonçalves🇧🇷 · Giorgio Torrieri🇧🇷

    In this addendum to [1], we apply the techniques developed in that paper to the $J/\Psi$ and ${\rm Y}$ spin alignement measurements in [2]. We argue that while the data points to a maximally impure density matrix, consistent with Cooper-Frye/Statistical model freeze-out, a measurement of the dependence of the $\varphi$-sensitive coefficients on the azimuthal angle with respect to the reaction plane would be the crucial test of this conclusion.

    ↳ nucl-thhep-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.