Tue·May 26, 2020Tuesday·May 26, 2020

1. 01*

   Real scalar field, non-relativistic limit, and cosmological expansion

   Lars Helge Heyen🇩🇪 · Stefan Floerchinger🇩🇪

   The existing transformation from a relativistic real scalar field to a complex non-relativistic scalar field by Namjoo, Guth, and Kaiser is generalized from Minkowski space to a more general background metric. In that case the transformation is not purely algebraic any more but determined by a differential equation. We apply the generalized transformation to a real scalar with ${\varphi }^4$ interaction on an Friedmann-Lemaître-Robertson-Walker cosmologically expanding background and calculate the resulting non-relativistic action up to second order in small parameters. We also show that the transformation can be interpreted as a Bogoliubov transformation between relativistic and non-relativistic creation and annihilation operators and comment on emerging symmetries in the non-relativistic theory.

   hep-phPRD(2020)·10 citations
2. 02*

   Study on the anomalous quartic $W^{+}{W}^{-}\gamma \gamma$ couplings of electroweak bosons in $e^{-}p$ collisions at the LHeC and the FCC-he

   A. Gutiérrez-Rodríguez🇲🇽 · M. A. Hernández-Ruíz🇲🇽 · E. Gurkanli🇹🇷 · V. Ari🇹🇷 · M. Köksal🇹🇷

   In this paper, a study is carried out on the $e^{-}p\to e^{-}{\gamma }^{\ast }p\to p{W}^{+}\gamma {\nu }_e$ production to probe quartic $W^{+}{W}^{-}\gamma \gamma$ couplings using 10, 100 $\mathrm{f}{\mathrm{b}}^{-1}$ of $e^{-}p$ collisions data at $\sqrt{s}$= 1.30, 1.98 GeV at the Large Hadron electron Collider (LHeC) and 100, 1000 $\mathrm{f}{\mathrm{b}}^{-1}$ with $\sqrt{s}$= 3.46, 5.29 GeV at the Future Circular Collider-hadron electron (FCC-he). Production cross-sections are determined for both at leptonic and hadronic decay channel of the $W$-boson. With the data from future $e^{-}p$ colliders, it is possible to obtain sensitivity measures at $95\%$ C.L. on the anomalous $f_{M,i}/{\Lambda }^4$ and $f_{T,i}/{\Lambda }^4$ couplings which are competitive with the limits obtained by the LHC, as well as with others limits reported in the literature. The production mode $e^{-}p\to e^{-}{\gamma }^{\ast }p\to p{W}^{+}\gamma {\nu }_e$ in $e^{-}p$ collisions offers a window for study the quartic $W^{+}{W}^{-}\gamma \gamma$ electroweak bosons couplings at the LHeC and the FCC-he, which provides a much cleaner collision environment than the LHC.

   hep-phEPJC(2021)·17 citations
3. 03*

   Froissart Bound, Diffraction Scattering of Hadrons and Scaling at Asymptotic Energies

   Aruna Kumar Nayak🇮🇳 · Jnanadeva Maharana🇮🇳

   The Froissart bound on the total cross section is subjected to test against very high energy data. We have found no clear evidence for its violation. The scaling property of differential cross section in the diffraction region is investigated. It exhibits scaling in the ISR, SPS, Tevatron and LHC energy domain which had hitherto remained unexplored. The slope of the diffraction peak is fitted and the data are tested against the rigorous bounds.

   hep-phhep-exnucl-thPRD(2020)·3 citations
4. 04*

   Axial-tensor Meson Family at $T\ne 0$

   J.Y. Süngü🇹🇷 · A. Türkan🇹🇷 · E. Sertbakan🇹🇷 · E. Veli Veliev🇹🇷

   The mass and decay constant of the axial-tensor meson nonets ${\rho }_2,{\omega }_2$ and a missing member and also their first excited states are analyzed by the Thermal QCD sum rules model including QCD condensates up to dimension five. Mass and decay constant values in terms of variations of temperature are very well stable from $T=0$ up to ~$T\cong 120\mathrm{MeV}$. However nearly after these threshold, our numerical analysis indicate that they begin to diminish with increasing temperature. Mass value of these mesons and their first excited states decrease about $(1-13\%)$ compared to vacuum values and $(10-26\%)$ for the decay constants according to PDG data and $(9-26\%)$ and $(2-34\%)$ respectively concerning Regge Trajectory Model in the corresponding Thermal QCD sum rules calculations. The experimental results are already copious, but expected to grow up at ongoing and future heavy-ion experimental programs allowing us to compare our results.

   hep-phEPJC(2020)·11 citations
5. 05*

   NLO corrections to Vector Dark Matter Direct Detection -- An update

   Seraina Glaus🇩🇪 · Margarete Mühlleitner🇩🇪 · Jonas Müller🇩🇪 · Shruti Patel🇩🇪 · Rui Santos🇵🇹

   In this work we present an update to a previous calculation of the Next-to-Leading Order (NLO) corrections to the Vector Dark Matter (VDM) direct detection cross section. The model under investigation is a minimal extension of the Standard Model (SM) with one extra vector boson and one extra complex scalar field, where the vector is the DM candidate. We have computed the spin-independent cross section for the scattering of the VDM particle with a nucleon. We now provide an update to the NLO cross section for the direct detection of the DM particle. We further discuss the phenomenological implications of the NLO corrections for the sensitivity of the direct detection DM experiments.

   hep-phPoS(2020)·8 citations
6. 06*

   Constraints on light dark matter particles using white dwarf stars

   Grigoris Panotopoulos🇵🇹 · Ilídio Lopes🇵🇹

   We report constraints on the nucleon-dark matter particle cross section using the internal luminosity of observed white dwarf stars in the globular cluster Messier 4. Our results cover the parameter space corresponding to relatively light dark matter particles, in the mass range $0.1GeV-5GeV$, which is known to be very difficult to be probed by direct dark matter searches. The additional luminosity coming from self-annihilations of dark matter particles captured inside the stars must not exceed the observed luminosity. Imposing that condition, we obtain for the spin independent cross section of light dark matter particles on baryons ${\sigma }_{N\chi }$ the upper bound: ${\sigma }_{N\chi }<4\times 10^{-41}\mathrm{c}{\mathrm{m}}^2$.

   hep-phastro-ph.HEastro-ph.SRInt.J.Mod.Phys.D(2020)·31 citations
7. 07*

   The strangest non-strange meson is not so strange after all

   Saša Ceci🇭🇷 · Marin Vukšić🇬🇧 · Branimir Zauner

   The broad non-strange meson $f_0$(500) is considered to be a non-Breit-Wigner resonance. It is generally assumed that if a resonance is broad it can hardly be described by a Breit-Wigner form. We show here that is not true neither for the broad Z boson, nor for the much narrower $\Delta (1232)$, and explain why the $f_0$(500) fits with them perfectly. Key differences between them boil down to a single parameter: the angle at which we see the resonance pole from the threshold, which explains the background, the residue phase, and the difference between the pole and Breit-Wigner parameters.

   hep-ph3 citations
8. 08*

   Mass spectra of heavy pseudoscalars using instantaneous Bethe-Salpeter equation with different kernels

   Wei Li🇨🇳 · Ying-Long Wang🇨🇳 · Tai-Fu Feng🇨🇳 · Guo-Li Wang🇨🇳

   We solved the instantaneous Bethe-Salpeter equation for heavy pseudoscalars in different kernels, where the kernels are obtained using linear scalar potential plus one gluon exchange vector potentials in Feynman gauge, Landau gauge, Coulomb gauge and time-component Coulomb gauge. We obtained the mass spectra of heavy pseudoscalars, and compared the results between different kernels, found that using the same parameters we obtain the smallest mass splitting in time-component Coulomb gauge, the similar largest mass splitting in Feynman and Coulomb gauges, middle size splitting in Landau gauge.

   hep-phEPJC(2020)·4 citations
9. 09*

   Cherenkov radiation in a strong magnetic field

   Cheng-Yang Lee🇨🇳

   According to quantum electrodynamics, in a strong magnetic field that is constant and spatially uniform, the vacuum becomes polarized with a refractive index greater than unity. As a result, ultra-relativistic charged particles travelling in such media can emit Cherenkov radiation with a power spectrum directly proportional to the photon frequency $\omega$. Therefore, by extrapolating $\omega$ beyond the critical synchrotron frequency ${\omega }_c$, the Cherenkov radiation will eventually dominate over its synchrotron counterpart. However, such an extrapolation is not possible. We show that in the framework of effective field theory, the maximal attainable photon frequency ${\omega }_{\text{mbox}max}$ is about four order of magnitude less than ${\omega }_c$. At $\omega ={\omega }_{\text{mbox}max}$, given the ${\gamma }_e$-factor of an electron travelling normal to a constant and spatially uniform magnetic field $\mathbf{B}$, the spectrum of Cherenkov radiation becomes dominant when ${\gamma }_e(|\mathbf{B}|/\text{mbox}Gauss)\gtrsim 4.32\times 10^{19}$. Nevertheless, detecting the Cherenkov radiation in astrophysical environments remains challenging since its spectral flux density is about three orders of magnitude less than the synchrotron radiation.

   hep-phPLB(2020)·8 citations
10. 10*

    The interplay of transverse degrees of freedom and axial-vector mesons with short-distance constraints in g-2

    Pere Masjuan🇪🇸 · Pablo Roig🇲🇽 · Pablo Sanchez-Puertas🇪🇸

    We revisit well-known short-distance constraints relating the hadronic light-by light Green's function to the $⟨VVA⟩$ one, that have been a subject of debate over the past years in the context of the muon $(g-2)$. Specifically, we identify a relation among the longitudinal and transverse degrees of freedom that is enforced by the axial anomaly that, by contrast, has not received attention in the past. Such relation allows, among other things, to overcome the problem of basis ambiguities when describing axial-vector mesons transition form factors, but further applications are discussed as well, with special focus on the role of axial-vector mesons in the HLbL contribution to the muon $(g-2)$. Our results should also contribute to a better understanding of the, so far, controversial interplay among short-distance constraints with longitudinal and transverse degrees of freedom, such as axial-vector mesons. This is key to confront the theoretical and experimental result for the muon $(g-2)$ that, currently, exhibits a $4.2\sigma$ tension.

    hep-phJ.Phys.G(2022)·93 citations
11. 11*

    Achieving effective renormalization scale and scheme independence via the Principle of Observable Effective Matching

    Farrukh A. Chishtie🇨🇦

    In this work, we explicate a new approach for eliminating renormalization scale and scheme (RSS) dependence in observables. We develop this approach by matching RSS dependent observables (such as cross-sections and decay rates) to a theory which is independent of both these forms of dependencies. We term the fundamental basis behind this approach as the principle of observable effective matching (POEM), which entails matching of a scale- and scheme-dependent observable with the fully physical scale (PS) and dynamical scale-dependent theory at loop orders at which RSS independence is guaranteed. This is aimed toward achieving so-called "effective" RSS-independent expressions as the resulting dynamical dependence is derived from a particular order in RSS-dependent perturbation theory. With this matching at a PS at which the coupling (and masses) is experimentally determined at this scale, we obtain an "effective theoretical observable (ETO)", a finite-order RSS-independent version of the RSS-dependent observable. We illustrate our approach with a study of the cross-section ratio $R_{e^{+}{e}^{-}}$ for $e^{+}{e}^{-}\to$ hadrons, which is demonstrated to achieve scale and scheme independence utilizing the three- and four-loop order MS scheme expression in QCD perturbation theory via matching at both one-loop and two-loop orders for obtaining the ETO. With two-loop matching, we obtain an ETO prediction of $\frac{3}{11}{R}_{e^{+}{e}^{-}}^{eff}=1.052431_{-0.0006}^{+0.0006}$ at $Q=31.6GeV$, which is in excellent agreement with the experimental value of $\frac{3}{11}{R}_{e^{+}{e}^{-}}^{exp}=1.0527_{-0.005}^{+0.005}$.

    hep-phgr-qchep-thquant-phFront.Phys.(2022)·12 citations
12. 12*

    Storage Ring Probes of Dark Matter and Dark Energy

    Peter W. Graham🇺🇸 · Selcuk Haciomeroglu🇰🇷 · David E. Kaplan🇺🇸 · Zhanibek Omarov🇰🇷 · Surjeet Rajendran🇺🇸 · Yannis K. Semertzidis🇰🇷

    We show that proton storage ring experiments designed to search for proton electric dipole moments can also be used to look for the nearly dc spin precession induced by dark energy and ultra-light dark matter. These experiments are sensitive to both axion-like and vector fields. Current technology permits probes of these phenomena up to three orders of magnitude beyond astrophysical limits. The relativistic boost of the protons in these rings allows this scheme to have sensitivities comparable to atomic co-magnetometer experiments that can also probe similar phenomena. These complementary approaches can be used to extract the micro-physics of a signal, allowing us to distinguish between pseudo-scalar, magnetic and electric dipole moment interactions.

    hep-phhep-exhep-thPRD(2021)·75 citations
13. 13*

    Electromagnetic form factors of octet baryons with the nonlocal chiral effective theory

    Mingyang Yang🇨🇳 · Ping Wang🇨🇳

    The electromagnetic form factors of octet baryons are investigated with the nonlocal chiral effective theory. The nonlocal interaction generates both the regulator which makes the loop integral convergent and the $Q^2$ dependence of form factors at tree level. Both octet and decuplet intermediate states are included in the one loop calculation. The momentum dependence of baryon form factors are studied up to 1 GeV${}^2$ with the same number of parameters as for the nucleon form factors. The obtained magnetic moments of all the baryon octets as well as the radii are in good agreement with the experimental data and/or lattice simulation.

    hep-phPRD(2020)·18 citations
14. 14*

    Purely Triplet Seesaw and Leptogenesis within Cosmological Bound, Dark Matter and Vacuum Stability

    Mina Ketan Parida (Siksha 'O' Anusandhan, Deemed to be Univ.)🇮🇳 · Mainak Chakraborty (Phys. Dept., Cacutta Univ.)🇮🇳 · Swaraj Kumar Nanda (Siksha 'O' Anusandhan, Deemed to be Univ.)🇮🇳 · Riyanka Samantaray (Siksha 'O' Anusandhan, Deemed to be Univ.)🇮🇳

    In a novel standard model extension it has been suggested that, even in the absence of right-handed neutrinos and type-I seesaw, purely triplet leptogenesis leading to baryon asymmetry of the universe can be realised by two heavy Higgs triplets which also provide type-II seesaw ansatz for neutrino masses. In this work we discuss this model for hierarchical neutrino masses in concordance with recently determined cosmologocal bounds and oscillation data including ${\theta }_{23}$ in the second octant and large Dirac CP phases. We also address the issues on dark matter and vacuum stability of the scalar potential in a minimal extension of this model. We find that for both normal and inverted orderings the model fits the oscillation data with the sum of the three neutrino masses consistent with cosmological bounds determined from Planck satellite data. In addition using this model ansatz for CP-asymmetry and solutions of Boltzmann equations, we also show how successful prediction of baryon asymmetry emerges in the cases of both unflavoured and two-flavoured leptogeneses. With additional $Z_2$ discrete symmetry, a minimal extension of this model is shown to be capable of predicting a scalar singlet WIMP dark matter in agreement with direct and indirect observations. Whereas in the original model, the renormalization group running of the scalar potential renders it negatve leading to vacuum instability, the presence of the dark matter in the minimally extended model ensures stability. Although the combined constraints due to relic density and direct detection cross section allow this scalar singlet dark matter mass to be $m_{\xi }=750$ GeV, the additional vacuum stability constraint pushes this limiting value to $m_{\xi }=1.3$ TeV which is verifiable by ongoing experiments. We also dicuss constraint on the model parameters for the radiative stability of the standard Higgs mass.

    hep-phhep-exNPB(2020)·6 citations
15. 15*

    Doubly Cabibbo-suppressed decays of antitriplet charmed baryons

    Guanbao Meng🇨🇳 · Sam Ming-Yin Wong🇹🇼 · Fanrong Xu🇨🇳

    Doubly Cabibbo-suppressed (DCS) nonleptonic weak decays of antitriplet charmed baryons are studied systematically in this work. The factorizable and nonfactorizable contributions can be classified explicitly in the topological-diagram approach and treated separately. In particular, the evaluation of nonfactorizable terms is based on the pole model in conjunction with current algebra. All three types of relevant non-perturbative parameters contributing factorizable and nonfactorizable terms are estimated in the MIT bag model. Branching fractions of all the DCS decays are predicted to be of order $10^{-4}\sim 10^{-6}$. In particular, we find that the three modes ${\Xi }_c^{+}\to {\Sigma }^{+}{K}^0,{\Sigma }^0{K}^{+}$ and ${\Xi }_c^0\to {\Sigma }^{-}{K}^{+}$ are as large as $(1\sim 2)\times 10^{-4}$, which are the most promising DCS channels to be measured. We also point out that the two DCS modes ${\Xi }_c^{+}\to {\Sigma }^{+}{K}^0$ and ${\Xi }_c^0\to {\Sigma }^0{K}^0$ are possible to be distinguished from ${\Xi }_c^{+}\to {\Sigma }^{+}{K}_S$ and ${\Xi }_c^0\to {\Sigma }^0{K}_S$. The decay asymmetries for all the channels with a kaon in their final states are found to be large in magnitude and negative in sign.

    hep-phhep-exJHEP(2020)·15 citations
16. 16*

    Fixed-order and merged parton-shower predictions for WW and WWj production at the LHC including NLO QCD and EW corrections

    Stephan Bräuer🇩🇪 · Ansgar Denner🇩🇪 · Mathieu Pellen🇬🇧 · Marek Schönherr🇬🇧 · Steffen Schumann🇩🇪

    First, we present a combined analysis of $\mathrm{p}\mathrm{p}\to {\mu }^{+}{\nu }_{\mu }{\mathrm{e}}^{-}{\bar{\nu }}_{\mathrm{e}}$ and $\mathrm{p}\mathrm{p}\to {\mu }^{+}{\nu }_{\mu }{\mathrm{e}}^{-}{\bar{\nu }}_{\mathrm{e}}\mathrm{j}$ at next-to-leading order, including both QCD and electroweak corrections. Second, we provide all-order predictions for $\mathrm{p}\mathrm{p}\to {\mu }^{+}{\nu }_{\mu }{\mathrm{e}}^{-}{\bar{\nu }}_{\mathrm{p}}+\mathrm{jets}$ using merged parton-shower simulations that also include approximate EW effects. A fully inclusive sample for WW production is compared to the fixed-order computations for exclusive zero- and one-jet selections. The various higher-order effects are studied in detail at the level of cross sections and differential distributions for realistic experimental set-ups. Our study confirms that merged predictions are significantly more stable than the fixed-order ones in particular regarding ratios between the two processes.

    hep-phhep-exJHEP(2020)·43 citations
17. 17*

    NLO QCD+NLO EW corrections to diboson production matched to parton shower

    Mauro Chiesa🇫🇷 · Carlo Oleari🇮🇹 · Emanuele Re🇫🇷

    We present the matching of NLO QCD and NLO EW corrections to parton showers for vector-boson pair production at the LHC. We consider leptonic final states, including resonant and non-resonant diagrams, spin correlations and off-shell effects. Our results are obtained interfacing the Recola2-Collier one-loop provider with the POWHEG-BOX-RES framework. We discuss our implementation, we validate it at fixed order, and we show our final results matched to parton shower. A by-product of our work is also a general interface between Recola2-Collier and POWHEG-BOX-RES. This is the first time that EW and QCD corrections to diboson production are consistently matched to parton showers.

    hep-phhep-exEPJC(2020)·54 citations
18. 18*

    Comment on "Landau equation and QCD sum rules for the tetraquark molecular states" [Phys. Rev. D 101, 074011 (2020)]

    Wolfgang Lucha🇦🇹 · Dmitri Melikhov🇷🇺 · Hagop Sazdjian🇫🇷

    Recently, a QCD sum-rule analysis of tetraquark molecular states has been published, having the objective of demonstrating that our previously formulated tetraquark-adequate QCD sum rules are not correct. This comment brings to the attention of the reader inconsistencies in that article and explains some subtle details of QCD sum rules for exotic states.

    hep-ph1 citation
19. 19*

    Characterizing Proton-Proton Collisions at the Large Hadron Collider with Thermal Properties

    Dushmanta Sahu🇮🇳 · Raghunath Sahoo🇮🇳

    High-multiplicity proton-proton (pp) collisions at the Large Hadron Collider (LHC) energies have created a new domain of research to look for a possible formation of quark-gluon plasma in these events. In this paper, we estimate various thermal properties of the matter formed in pp collisions at the LHC energies, such as mean free path, isobaric expansivity, thermal pressure, and heat capacity using a thermodynamically consistent Tsallis distribution function. Particle species-dependent mean free path and isobaric expansivity are studied as functions of final state charged particle multiplicity for pp collisions at the center-of-mass energy $\sqrt{s}$ = 7 TeV. The effects of degree of non-extensivity, baryochemical potential, and temperature on these thermal properties are studied. The findings are compared with the theoretical expectations.

    hep-phhep-exnucl-exnucl-thMDPI Physics(2021)·8 citations
20. 20*

    Conformal Unification in a Quiver Theory and Gravitational Waves

    Claudio Corianò🇮🇹 · Paul H. Frampton🇮🇹 · Alessandro Tatullo🇮🇹

    The detection of a stochastic background of gravitational waves can reveal details about first-order phase transitions (FOPTs) at a time of $10^{-13}s$ of the early universe. We specifically discuss quiver-type GUTs which avoid both proton decay and a desert hypothesis. A quiver based on $SU(3{)}^{12}$ which breaks at a $E=4000$ GeV to trinification $SU(3{)}^3$ has a much larger ($g_{\ast }=1,272$) number of effective massless degrees of freedom than the Standard Model. Assuming a FOPT for this model we investigate the strain sensitivity of this model for a wide range of FOPT parameters.

    hep-phPLB(2020)·2 citations
21. 21*

    Probing Lepton Flavor Models at Future Neutrino Experiments

    Mattias Blennow🇪🇸 · Monojit Ghosh🇸🇪 · Tommy Ohlsson🇸🇪 · Arsenii Titov🇮🇹

    Non-Abelian discrete symmetries provide an interesting opportunity to address the flavor puzzle in the lepton sector. However, the number of currently viable models based on such symmetries is rather large. High-precision measurements of the leptonic mixing parameters by future neutrino experiments, including ESSnuSB, T2HK, DUNE, and JUNO, will be crucial to test such models. We show that the complementarity among these experiments offers a powerful tool for narrowing down this broad class of lepton flavor models.

    hep-phhep-exPRD(2020)·18 citations
22. 22*

    A Cosmic Microscope for the Preheating Era

    JiJi Fan🇺🇸 · Zhong-Zhi Xianyu🇺🇸

    Light fields with spatially varying backgrounds can modulate cosmic preheating, and imprint the nonlinear effects of preheating dynamics at tiny scales on large scale fluctuations. This provides us a unique probe into the preheating era which we dub the "cosmic microscope.'' We identify a distinctive effect of preheating on scalar perturbations that turns the Gaussian primordial fluctuations of a light scalar field into square waves, like a diode. The effect manifests itself as local non-Gaussianity. We present a model, "modulated partial preheating," where this nonlinear effect is consistent with current observations and can be reached by near future cosmic probes.

    hep-phastro-ph.COhep-thJHEP(2021)·33 citations
23. 23*

    Recoil-free azimuthal angle for precision boson-jet correlation

    Yang-Ting Chien🇺🇸 · Rudi Rahn🇳🇱 · Solange Schrijnder van Velzen🇳🇱 · Ding Yu Shao🇨🇳 · Wouter J. Waalewijn🇳🇱 · Bin Wu🇨🇭

    The azimuthal decorrelation between a vector boson and a jet is an essential hard probe in high energy proton-proton and heavy-ion collisions. We overcome intrinsic limitations of previous studies by using a recoil-free axis, achieving unprecedented next-to-next-to-leading logarithmic accuracy with small nonperturbative corrections. This choice of axis also makes the observable robust in the presence of a large background. Furthermore, the azimuthal angle distribution is minimally changed when determined using only charged particle tracks, which offer superior angular resolution for precise measurements. Our effective field theory includes full jet dynamics, and we find contributions from linearly-polarized gluon transverse momentum distributions in the initial and final state.

    hep-phhep-exnucl-thPLB(2021)·65 citations
24. 24*

    Flavour Violating Effects of Yukawa Running in SMEFT

    Jason Aebischer🇺🇸 · Jacky Kumar🇨🇦

    We study Yukawa Renormalization Group (RG) running effects in the context of the Standard Model Effective Theory (SMEFT).The Yukawa running being flavour dependent leads to RG-induced off-diagonal entries, so that initially diagonal Yukawa matrices at the high scale have to be rediagonalized at the electroweak (EW) scale. Performing such flavour rotations can lead to flavour violating operators which differ from the ones obtained through SMEFT RG evolution. We show, that these flavour rotations can have a large impact on low-energy phenomenology. In order to demonstrate this effect, we compare the two sources of flavour violation numerically as well as analytically and study their influence on several examples of down-type flavour transitions. For this purpose we consider $B_s-{\bar{B}}_s$ mixing, $b\to s\gamma$, $b\to s\ell \ell$ as well as electroweak precision observables. We show that the rotation effect can be comparable or even larger than the contribution from pure RGE evolution of the Wilson coefficients.

    hep-phJHEP(2020)·38 citations
25. 25*

    Reconstructing Effective Lagrangians Embedding Residual Family Symmetries

    Jordan Bernigaud🇩🇪 · Ivo de Medeiros Varzielas🇵🇹 · Jim Talbert🇩🇰

    We consider effective Lagrangians which, after electroweak- and family-symmetry breaking, yield fermionic mass matrices and/or other flavoured couplings exhibiting residual family symmetries (RFS). Thinking from the bottom up, these RFS intimately link ultraviolet (UV) Beyond-the-Standard Model (BSM) physics to infrared flavour phenomenology without direct reference to any (potentially unfalsifiable) UV dynamics. While this discussion is typically performed at the level of RFS group generators and the UV flavour groups they can close, we now also focus on the RFS-implied shape of the low-energy mass/coupling matrices. We then show how this information can be used to algorithmically guide the reconstruction of an effective Lagrangian, thereby forming top-down models realizing the typical bottom-up phenomenological conclusions. As a first application we take results from scans of finite groups capable of controlling (through their RFS) CKM or PMNS mixing within the SM alone. We then extend this to recently studied scenarios where RFS also control special patterns of leptoquark couplings, thus providing proof-in-principle completions for such `Simplified Models of Flavourful Leptoquarks.'

    hep-phEPJC(2021)·7 citations
26. 26*

    A singular way to search for heavy resonances in missing energy events

    Chan Beom Park🇰🇷

    The phase space of visible particles in missing energy events may have singularity structures. The singularity variables are devised to capture the singularities effectively for given event topology. They can greatly improve the discovery potential of new physics signals as well as to extract the mass spectrum information at hadron colliders. Focusing on the antler decay topology of resonance, we derive a novel singularity variable whose distribution has endpoints directly correlated with the resonance mass. As a practical application, we examine the applicability of the singularity variable to the searches for heavy neutral Higgs bosons in the two-Higgs doublet model.

    hep-phhep-exJHEP(2020)·9 citations
27. 27*

    Determination of $\alpha (M_z)$ from an hyperasymptotic approximation to the energy of a static quark-antiquark pair

    Cesar Ayala🇨🇱 · Xabier Lobregat🇪🇸 · Antonio Pineda🇪🇸

    We give the hyperasymptotic expansion of the energy of a static quark-antiquark pair with a precision that includes the effects of the subleading renormalon. The terminants associated to the first and second renormalon are incorporated in the analysis when necessary. In particular, we determine the normalization of the leading renormalon of the force and, consequently, of the subleading renormalon of the static potential. We obtain $Z_3^F(n_f=3)=2Z_3^V(n_f=3)=0.37(17)$. The precision we reach in strict perturbation theory is next-to-next-to-next-to-leading logarithmic resummed order both for the static potential and for the force. We find that the resummation of large logarithms and the inclusion of the leading terminants associated to the renormalons are compulsory to get accurate determinations of ${\Lambda }_{\overline{\mathrm{MS}}}$ when fitting to short-distance lattice data of the static energy. We obtain ${\Lambda }_{\overline{\mathrm{MS}}}^{(n_f=3)}=338(12)$ MeV and $\alpha (M_z)=0.1181(9)$. We have also found strong consistency checks that the ultrasoft correction to the static energy can be computed at weak coupling in the energy range we have studied.

    hep-phhep-lathep-thJHEP(2020)·59 citations
28. 28*

    The Techni-Pati-Salam Composite Higgs

    Giacomo Cacciapaglia🇫🇷 · Shahram Vatani🇫🇷 · Chen Zhang🇹🇼

    Composite Higgs models can be extended to the Planck scale by means of the partially unified partial compositeness (PUPC) framework. We present in detail the Techni-Pati-Salam model, based on a renormalizable gauge theory $SU(8{)}_{PS}\times SU(2{)}_L\times SU(2{)}_R$. We demonstrate that masses and mixings for all generations of standard model fermions can be obtained via partial compositeness at low energy, with four-fermion operators mediated by either heavy gauge bosons or scalars. The strong dynamics is predicted to be that of a confining $Sp(4{)}_{\mathrm{HC}}$ gauge group, with hyper-fermions in the fundamental and two-index anti-symmetric representations, with fixed multiplicities. This motivates for Lattice studies of the Infra-Red near-conformal walking phase, with results that may validate or rule out the model. This is the first complete and realistic attempt at providing an Ultra-Violet completion for composite Higgs models with top partial compositeness. In the baryon-number conserving vacuum, the theory also predicts a Dark Matter candidate, with mass in the few TeV range, protected by semi-integer baryon number.

    hep-phhep-latPRD(2021)·17 citations
29. 29*

    Neutrino charge constraints from scattering to the weak gravity conjecture to neutron stars

    Arindam Das🇯🇵 · Diptimoy Ghosh🇮🇳 · Carlo Giunti🇮🇹 · Arun Thalapillil🇮🇳

    In various extensions of the Standard Model of particle physics, and intriguingly even in the three-generation Standard Model without neutrino masses, neutrinos are allowed to have very tiny electric charges. After a review of the theoretical scenarios that allow the emergence of such charges, we discuss the existing observational limits and we derive new stringent direct upper bounds for the charges of the muon and tau neutrinos. We also point out a flavor-universal lower bound on neutrino charges which is obtained from the weak gravity conjecture, that is based on the hypothesis that gravity is the weakest force. We finally present a new flavor-universal upper bound on neutrino charges based on astrophysical observations of Magnetars.

    hep-phastro-ph.HEhep-exhep-thPRD(2020)·22 citations
30. 30*

    A Higgs Doublet + Higgs Singlet Scheme with Negative Kinetic Term for Neutrino Mass Generation

    Jianlong Lu🇸🇬

    In this paper, we propose a scheme for neutrino mass generation. A Higgs singlet is introduced in the Standard Model of particle physics (SM). All of this new singlet and the charged and neutral Higgs fields in the original Higgs doublet are assumed to have nonzero vacuum expectation values (VEVs). The normal hierarchy of neutrino masses is evidently preferred in our scheme. The neutrino masses are explicitly calculated.

    hep-ph2 citations
31. 31*

    Kink-Antikink Collisions in the Periodic ${\phi }^4$ Model

    M. Mohammadi🇮🇷 · R. Dehghani🇨🇦

    We borrow the form of potential of the well-known kink-bearing ${\phi }^4$ system in the range between its two vacua and paste it repeatedly into the other ranges to introduce the periodic ${\phi }^4$ system. The paper is devoted to providing a comparative numerical study of the properties of the two systems. Although the two systems are quite similar for a kink (antikink) solution, they usually exhibit different behaviors throughout collisions. For instance, they have different critical velocities, different results during collisions, and a different rule in their quasi-fractal structures. Their quasi-fractal structures will be studied in the disturbed kink-antikink collisions as well. Hence, three types of scattering windows will be introduced with respect to the incoming speed, the amplitude, and initial phase of the internal mode, respectively. Moreover, a detailed comparative study of the collisions between two kinks and one antikink will be done at the end.

    ↳ nlin.PShep-phCommun.Nonlinear Sci.Numer.Simul.(2021)·24 citations
32. 32*

    On Higher Dimensional Self-Similar Axion-Dilaton Solutions

    Ehsan Hatefi🇮🇹 · Eleonora Vanzan🇮🇹

    We show that solutions of the self-similar gravitational collapse in the Einstein-axion-dilaton system exist in higher dimensional spacetimes. These solutions are invariant under spacetime dilation combined with internal SL(2,R) transformations. We rely on the recent setup and use it for the three different conjugacy classes (elliptic, parabolic and hyperbolic) in higher dimensions. Lastly, we identify new families of physically distinguishable self-similar solutions for all three conjugacy classes in six and seven dimensions.

    ↳ hep-thgr-qchep-phmath-ph+1EPJC(2020)·7 citations
33. 33*

    Existence and Stability of Static Spherical Fluid Shells in a Schwarzschild-Rindler-anti-de Sitter Metric

    G. Alestas🇬🇷 · G. V. Kraniotis🇬🇷 · L. Perivolaropoulos🇬🇷

    We demonstrate the existence of static stable spherical fluid shells in the Schwarzschild-Rindler-anti-de Sitter (SRAdS) spacetime where $d{s}^2=f(r)d{t}^2-\frac{d{r}^2}{f(r)}-r^2(d{\theta }^2+{\sin }^2\theta d{\varphi }^2)$ with $f(r)=1-\frac{2Gm}{r}+2br-\frac{\Lambda }{3}{r}^2$. This is an alternative to the well known gravastar geometry where the stability emerges due to the combination of the repulsive forces of the interior de Sitter space with the attractive forces of the exterior Schwarzschild spacetime. In the SRAdS spacetime the repulsion that leads to stability of the shell comes from a negative Rindler term while the Schwarzschild and anti-de Sitter terms are attractive. We demonstrate the existence of such stable spherical shells for three shell fluid equations of state: vacuum shell ($p=-\sigma$), stiff matter shell ($p=\sigma$) and dust shell ($p=0$) where $p$ is the shell pressure and $\sigma$ is the shell surface density. We also identify the metric parameter conditions that need to be satisfied for shell stability in each case. The vacuum stable shell solution in the SRAdS spacetime is consistent with previous studies by two of the authors that demonstrated the existence sf stable spherical scalar field domain walls in the SRAdS spacetime.

    ↳ gr-qchep-phhep-thPRD(2020)·13 citations
34. 34*

    The Cosmological OTOC: Formulating new cosmological micro-canonical correlation functions for random chaotic fluctuations in Out-of-Equilibrium Quantum Statistical Field Theory

    Sayantan Choudhury🇩🇪

    The out-of-time-ordered correlation (OTOC) function is an important new probe in quantum field theory which is treated as a significant measure of random quantum correlations. In this paper, with the slogan "Cosmology meets Condensed Matter Physics" we demonstrate a formalism using which for the first time we compute the Cosmological OTOC during the stochastic particle production during inflation and reheating following canonical quantization technique. In this computation, two dynamical time scales are involved, out of them at one time scale the cosmological perturbation variable and for the other the canonically conjugate momentum is defined, which is the strict requirement to define time scale separated quantum operators for OTOC and perfectly consistent with the general definition of OTOC. Most importantly, using the present formalism not only one can study the quantum correlation during stochastic inflation and reheating, but also study quantum correlation for any random events in Cosmology. Next, using the late time exponential decay of cosmological OTOC with respect to the dynamical time scale of our universe which is associated with the canonically conjugate momentum operator in this formalism we study the phenomena of quantum chaos by computing the expression for {\it Lyapunov spectrum}. Further, using the well known Maldacena Shenker Stanford (MSS) bound, on Lyapunov exponent, $\lambda \le 2\pi /\beta$, we propose a lower bound on the equilibrium temperature, $T=1/\beta$, at the very late time scale of the universe. On the other hand, with respect to the other time scale with which the perturbation variable is associated, we find decreasing but not exponentially decaying behaviour, which quantifies the random correlation at out-of-equilibrium. Finally, we have studied the classical limit of the OTOC to check the consistency with the large time limiting behaviour.

    ↳ hep-thcond-mat.stat-mechgr-qchep-ph+1Symmetry(2020)·41 citations
35. 35*

    Early mass varying neutrino dark energy: Nugget formation and Hubble anomaly

    Antareep Gogoi🇮🇳 · Ravi Kumar Sharma🇮🇳 · Prolay Chanda🇺🇸 · Subinoy Das🇮🇳

    We present a novel scenario, in which light ($\sim$ few \rm{eV}) dark fermions (sterile neutrinos) interact with a scalar field like in mass varying neutrino dark energy theories. As the $\mathrm{eV}$ sterile states naturally become non-relativistic before the Matter Radiation Equality (MRE), we show that the neutrino-scalar fluid develops strong perturbative instability followed by the formation of neutrino-nuggets and the early dark energy behaviour disappears around MRE. The stability of the nugget is achieved when the Fermi pressure balances the attractive scalar force and we numerically find the mass and radius of heavy cold nuggets by solving for the static configuration for the scalar field. We find that for the case when DM nugget density is sub-dominant and most of the early DE energy goes into scalar field dynamics, it can in principle relax the Hubble anomaly. Especially when a kinetic energy dominated phase appears after the phase transition, the DE density dilutes faster than radiation and satisfy the requirements for solving $H_0$ anomaly. In our scenario, unlike in originally proposed early dark energy theory, the dark energy density is controlled by ($\mathrm{eV}$) neutrino mass and it does not require a fine tuned EDE scale. We perform a MCMC analysis and confront our model with Planck + SHOES and BAO data and find an evidence for non-zero neutrino-scalar EDE density during MRE. Our analysis shows that this model is in agreement of nearly 1.3$\sigma$ with SHOES measurement which is $H_0=74.03\pm 1.42$ km/s/Mpc.

    ↳ astro-ph.COgr-qchep-phApJ(2021)·97 citations
36. 36*

    Holographic Schwinger effect in the confining background with D-instanton

    Si-wen Li🇨🇳

    Using the gauge-gravity duality, we study the holographic Schwinger effect by performing the potential analysis on the confining D3- and D4-brane background with D-instantons then evaluate the pair production/decay rate by taking account into a fundamental string and a single flavor brane respectively. The two confining backgrounds with D-instantons are obtained from the black D(-1)-D3 and D0-D4 solution with a double Wick rotation. The total potential and pair production/decay rate in the Schwinger effect are calculated numerically by examining the NG action of a fundamental string and the DBI action of a single flavor brane all in the presence of an electric field. In both backgrounds our numerical calculation agrees with the critical electric field evaluated from the DBI action and shows the potential barrier is increased by the presence of the D-instantons, thus the production/decay rate is suppressed by the D-instantons. Our interpretation is that particles in the dual field theory could acquire an effective mass through the Chern-Simons interaction or the theta term due to the presence of D-instantons so that the pair production/decay rate in Schwinger effect is suppressed since it behaves as $e^{-m^2}$. Our conclusion is in agreement with the previous results obtained in the deconfined D(-1)-D3 background at zero temperature limit and from the approach of the flavor brane in the D0-D4 background. In this sense, this work may be also remarkable to study the phase transition in Maxwell-Chern-Simons theory and observable effects by the theta angle in QCD.

    ↳ hep-thhep-phEPJC(2021)·8 citations
37. 37*

    Dark matter annihilation in $\omega$ Centauri: Astrophysical implications derived from the MWA radio data

    Arpan Kar🇮🇳 · Biswarup Mukhopadhyaya🇮🇳 · Steven Tingay🇦🇺 · Ben McKinley🇦🇺 · Marijke Haverkorn🇳🇱 · Sam McSweeney🇦🇺 · Natasha Hurley-Walker🇦🇺 · Sourav Mitra🇮🇳 · Tirthankar Roy Choudhury🇮🇳

    We present an analysis of Murchison Widefield Array radio telescope data from $\omega$ Cen, possibly a stripped dwarf spheroidal galaxy core captured by our Galaxy. Recent interpretations of Fermi-LAT $\gamma$-ray data by Brown {\it et al.} (2019) and Reynoso-Cordova {\it et al.} (2019) suggest that $\omega$ Cen may contain significant Dark Matter. We utilise their best-fit Dark Matter annihilation models, and an estimate of the magnetic field strength in $\omega$ Cen, to calculate the expected radio synchrotron signal from annihilation, and show that one can usefully rule out significant parts of the magnetic field - diffusion coefficient plane using our current observational limits on the radio emission. Improvement by a factor of 10-100 on these limits could constrain the models even more tightly.

    ↳ astro-ph.HEhep-phPhys.Dark Univ.(2020)·9 citations
38. 38*

    Isovector parton distribution functions of the proton on a superfine lattice

    Zhouyou Fan🇺🇸 · Xiang Gao🇺🇸 · Ruizi Li🇺🇸 · Huey-Wen Lin🇺🇸 · Nikhil Karthik🇺🇸 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Sergey Syritsyn🇺🇸 · Yi-Bo Yang🇨🇳 · Rui Zhang🇺🇸

    We study isovector unpolarized and helicity parton distribution functions (PDF) of the proton within the framework of Large Momentum Effective Theory. We use a gauge ensemble, generated by the MILC Collaboration, with a superfine lattice spacing of $0.042$ fm and a pion mass of $310$ MeV, enabling us to simultaneously reach sub-fermi spatial separations and larger nucleon momenta. We compare the spatial dependence of quasi-PDF matrix elements in different renormalization schemes with the corresponding results of the global fits, obtained using 1-loop perturbative matching. We present determinations of the first four moments of the unpolarized and helicity PDFs of proton from the Ioffe-time dependence of the isovector matrix elements, obtained by employing a ratio-based renormalization scheme.

    ↳ hep-lathep-phnucl-exnucl-thPRD(2020)·81 citations
39. 39*

    Finite size effect on Dissociation and Diffusion of chiral partners in Nambu-Jona-Lasinio model

    Paramita Deb🇮🇳 · Sabyasachi Ghosh🇮🇳 · Jai Prakash🇮🇳 · Santosh Kumar Das🇮🇳 · Raghava Varma🇮🇳

    Along with masses of pion and sigma meson modes, their dissociation into quark medium provide a detail spectral structures of the chiral partners. Present article has studied a finite size effect on that detail structure of chiral partners by using the framework of Nambu-Jona-Lasinio model. Through this dissociation mechanism, their diffusions and conductions are also studied. The masses, widths, diffusion coefficients, conductivities of chiral partners are merged at different temperatures in restore phase of chiral symmetry, but merging points of all are shifted in lower temperature, when one introduce finite size effect into the picture. The strengths of diffusions and conductions are also reduced due to finite size consideration.

    ↳ nucl-thhep-phCPC(2022)·5 citations
40. 40*

    Constraints on neutrino mass in the scenario of vacuum energy interacting with cold dark matter after Planck 2018

    Hai-Li Li🇨🇳 · Jing-Fei Zhang🇨🇳 · Xin Zhang🇨🇳

    In this work, we investigate the constraints on the total neutrino mass in the scenario of vacuum energy interacting with cold dark matter (abbreviated as I$\Lambda$CDM) by using the latest cosmological observations. We consider four typical interaction forms, i.e., $Q=\beta H{\rho }_{\mathrm{de}}$, $Q=\beta H{\rho }_{\mathrm{c}}$, $Q=\beta H_0{\rho }_{\mathrm{de}}$, and $Q=\beta H_0{\rho }_{\mathrm{c}}$, in the I$\Lambda$CDM scenario. To avoid the large-scale instability problem in interacting dark energy models, we employ the extended parameterized post-Friedmann method for interacting dark energy to calculate the perturbation evolution of dark energy in these models. The observational data used in this work include the cosmic microwave background (CMB) measurements from the Planck 2018 data release, the baryon acoustic oscillation (BAO) data, the type Ia supernovae (SN) observation (Pantheon compilation), and the 2019 local distance ladder measurement of the Hubble constant $H_0$ from the Hubble Space Telescope. We find that, compared with those in the $\Lambda$CDM+$\sum m_{\nu }$ model, the constrains on $\sum m_{\nu }$ are looser in the four I$\Lambda$CDM+$\sum m_{\nu }$ models. When considering the three mass hierarchies of neutrinos, the constraints on $\sum m_{\nu }$ are tightest in the degenerate hierarchy case and loosest in the inverted hierarchy case. In addition, in the four I$\Lambda$CDM+$\sum m_{\nu }$ models, the values of coupling parameter $\beta$ are larger using the CMB+BAO+SN+$H_0$ data combination than that using the CMB+BAO+SN data combination, and $\beta >0$ is favored at more than 1$\sigma$ level when using CMB+BAO+SN+$H_0$ data combination. The issue of the $H_0$ tension is also discussed in this paper. We find that, compared with the $\Lambda$CDM+$\sum m_{\nu }$ model, the $H_0$ tension can be alleviated in the I$\Lambda$CDM+$\sum m_{\nu }$ model to some extent.

    ↳ astro-ph.COgr-qchep-phCommun.Theor.Phys.(2020)·30 citations
41. 41*

    Collective scalarization or tachyonization: when averaging fails

    Vitor Cardoso🇵🇹 · Arianna Foschi🇵🇹 · Miguel Zilhao🇵🇹

    Certain scalar-tensor theories of gravity provide negative-energy, tachyonic modes to a fundamental scalar inside matter, giving rise to non-perturbative phenomena around compact stars. Studies of this and other tachyonic instabilities always average over local matter properties. We use elementary, flat space models to understand possible collective effects and the accuracy of the averaging procedure. In particular, we consider bodies made of elementary constituents which do not, in isolation, scalarize because their compactness $\mathcal{C}$ is too small, $\mathcal{C}\lesssim {\mathcal{C}}_{\mathrm{crit}}$. We show that when the individual constituents have compactness smaller but close to the threshold, one is able to scalarize composite bodies through collective effects, and the compactness of the composite body can be made arbitrarily small. On the other hand, our results suggest that when the fundamental building blocks have very low compactness, then scalarization of the composite body requires a global compactness ${\mathcal{C}}_{\mathrm{global}}\gtrsim {\mathcal{C}}_{\mathrm{crit}}$. Thus, our results rule out scalarization of dilute bodies via collective effects.

    ↳ gr-qccond-mat.otherhep-phhep-thPRL(2020)·13 citations
42. 42*

    Gravitational Decoherence of Dark Matter

    Itamar Allali🇺🇸 · Mark P. Hertzberg🇺🇸

    Decoherence describes the tendency of quantum sub-systems to dynamically lose their quantum character. This happens when the quantum sub-system of interest interacts and becomes entangled with an environment that is traced out. For ordinary macroscopic systems, electromagnetic and other interactions cause rapid decoherence. However, dark matter (DM) may have the unique possibility of exhibiting naturally prolonged macroscopic quantum properties due to its weak coupling to its environment, particularly if it only interacts gravitationally. In this work, we compute the rate of decoherence for light DM in the galaxy, where a local density has its mass, size, and location in a quantum superposition. The decoherence is via the gravitational interaction of the DM overdensity with its environment, provided by ordinary matter. We focus on relatively robust configurations: DM perturbations that involve an overdensity followed by an underdensity, with no monopole, such that it is only observable at relatively close distances. We use non-relativistic scattering theory with a Newtonian potential generated by the overdensity to determine how a probe particle scatters off of it and thereby becomes entangled. As an application, we consider light scalar DM, including axions. In the galactic halo, we use diffuse hydrogen as the environment, while near the earth, we use air as the environment. For an overdensity whose size is the typical DM de Broglie wavelength, we find that the decoherence rate in the halo is higher than the present Hubble rate for DM masses $m_a\lesssim 5\times 10^{-7}$eV and in earth based experiments it is higher than the classical field coherence rate for $m_a\lesssim 10^{-6}$eV. When spreading of the states occurs, the rates can become much faster, as we quantify. Also, we establish that DM BECs decohere very rapidly and so are very well described by classical field theory.

    ↳ gr-qcastro-ph.COhep-phhep-th+1JCAP(2020)·32 citations
43. 43*

    QCD thermalization: Ab initio approaches and interdisciplinary connections

    Jürgen Berges🇩🇪 · Michal P. Heller🇩🇪 · Aleksas Mazeliauskas🇨🇭 · Raju Venugopalan🇺🇸

    Heavy-ion collisions at BNL's Relativistic Heavy Ion Collider and CERN's Large Hadron Collider provide strong evidence for the formation of a quark-gluon plasma, with temperatures extracted from relativistic viscous hydrodynamic simulations shown to be well above the transition temperature from hadron matter. How the strongly correlated quark-gluon matter forms in a heavy-ion collision, its properties off-equilibrium, and the thermalization process in the plasma, are outstanding problems in QCD. We review here the theoretical progress in this field in weak coupling QCD effective field theories and in strong coupling holographic approaches based on gauge-gravity duality. We outline the interdisciplinary connections of different stages of the thermalization process to non-equilibrium dynamics in other systems across energy scales ranging from inflationary cosmology, to strong field QED, to ultracold atomic gases, with emphasis on the universal dynamics of non-thermal and of hydrodynamic attractors. We survey measurements in heavy-ion collisions that are sensitive to the early non-equilibrium stages of the collision and discuss the potential for future measurements. We summarize the current state-of-the art in thermalization studies and identify promising avenues for further progress.

    ↳ hep-thcond-mat.quant-gashep-phnucl-th+1RMP(2021)·369 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.