Tue·Aug 2, 2022Tuesday·August 2, 2022

1. 01*

   Comprehensive Analysis of Charged Lepton Flavour Violation in the Symmetry Protected Type-I Seesaw

   Andreas Crivellin🇨🇭 · Fiona Kirk🇨🇭 · Claudio Andrea Manzari🇨🇭

   The type-I seesaw model is probably the most straightforward and best studied extension of the Standard Model that can account for the tiny active neutrino masses determined from neutrino oscillation data. In this article, we calculate the complete set of one-loop corrections to charged lepton flavour violating processes within this model. We give the results both using exact diagonalisation of the neutrino mass matrix, and at at leading order in the seesaw expansion (i.e. $\mathcal{O}(v^2/M_R^2)$). Furthermore, we perform the matching onto the $SU(2{)}_L$ invariant Standard Model Effective Field Theory at the dimension-6 level. These results can be used as initial conditions for the renormalisation group evolution from the right-handed neutrino scale down to the scale of the physical processes, which resums large logarithms. In our numerical analysis, we study the inverse seesaw limit, i.e. the symmetry protected type-I seesaw, where the Wilson coefficient of the Weinberg operator is zero such that sizeable neutrino Yukawas are permissible and relevant effects in charged lepton flavour violating observables are possible. We correlate the different charged lepton flavour violating processes, e.g. $\ell \to {\ell }^{\prime }\gamma$, $\ell \to 3{\ell }^{\prime }$, $\mu \to e$ conversion and $Z\to \ell {\ell }^{\prime }$, taking into account the constraints from electroweak precision observables and tests of lepton flavour universality.

   hep-phhep-exJHEP(2022)·18 citations
2. 02*

   GTMDs and the factorization of exclusive double Drell-Yan

   Miguel G. Echevarria🇪🇸 · Patricia A. Gutierrez Garcia🇪🇸 · Ignazio Scimemi🇪🇸

   Different exclusive processes have been proposed to access the generalized transverse momentum dependent distributions (GTMDs) with no proof of factorization, which allows to rigorously define the GTMDs. Using Soft Collinear Effective Theory we derive for the first time the factorization of the differential cross section for the exclusive double Drell-Yan process for the exclusive double Drell-Yan process pion N to N' gamma* gamma* to N' (l^+l^-)(l^+l^-), for small transverse momenta of the photons in terms of a perturbatively calculable hard factor, GTMDs and light-cone wave functions (LCWFs). We find that the hard factor of the process can be obtained from single inclusive Drell-Yan production so that one can resum logarithms at high orders in QCD. We also discuss the evolution of the GTMDs and the LCWFs.

   hep-phhep-exhep-latnucl-ex+1PLB(2023)·15 citations
3. 03*

   The role of long distance contribution to the $B\to K^{(\ast )}{\ell }^{+}{\ell }^{-}$ in the Standard Model

   Massimo Ladisa🇮🇹 · Pietro Santorelli🇮🇹

   We investigate rare semileptonic $B\to K^{\ast }{\ell }^{+}{\ell }^{-}$ by looking at the long distance contributions. Our analysis is limited to the very small values of physical accessible range of invariant mass of the leptonic couple $q^2$. We show that the light quarks loop has to be accounted for, along with the charming penguin contribution, in order to accurately compute the $q^2$-spectrum in the Standard Model. Such a long distance contribution may also play a role in the analysis of the lepton flavour universality violation in this process.

   hep-phhep-exPLB(2023)·9 citations
4. 04*

   A first step towards quantum simulating jet evolution in a dense medium

   João Barata🇺🇸

   The fast development of quantum technologies over the last decades has offered a glimpse to a future where the quantum properties of multi-particle systems might be more fully understood. In particular, quantum computing might prove crucial to explore many aspects of high energy physics unaccessible to classical methods. In this talk, we will describe how one can use digital quantum computers to study the evolution of QCD jets in quark gluons plasmas. We construct a quantum circuit to study single particle evolution in a dense QCD medium. Focusing on the jet quenching parameter $\hat{q}$, we present some early numerical results for a small quantum circuit. Future extensions of this strategy are also addressed.

   hep-phquant-phActa Phys.Polon.Supp.(2023)·0 citations
5. 05*

   Massive Right-handed Neutrinos in B Decays

   Hongkai Liu🇮🇱

   In this paper, we present the differential decay distributions for $\bar{B}\to D^{(\ast )}\ell \bar{X}$ decays with a massive right-handed neutrino in the low-energy effective field theory framework and show how the massive effects of the RH neutrinos can explain the positive value of the difference in forward-backward asymmetries, $\Delta A_{\text{FB}}\equiv A_{\text{FB}}^{\mu }-A_{\text{FB}}^e$, tentatively inferred from Belle data. We also make predictions for $q^2$ dependent angular observables to motivate future measurements.

   hep-ph0 citations
6. 06*

   Dipole polarizabilities of light pseudoscalar mesons within the Domain Model of QCD vacuum

   Sergei Nedelko🇷🇺 · Vladimir Voronin🇷🇺

   Dipole polarizabilities of light pseudoscalar mesons are calculated in the framework of the mean field approach to QCD vacuum and bosonization based on the statistical ensemble of almost everywhere homogeneous Abelian (anti-)self-dual gluon fields -- the domain model of QCD vacuum. In this approach, one derives a nonlocal effective action of meson fields which describes two-point correlation functions and all possible strong, weak and electromagnetic interactions of meson fields including their excited states. Specifically, the role of intermediate scalar meson fields in formation of the polarizabilities is addressed. Within the domain model, the propagators of scalar meson fields composed of light quark-anti-quark pairs have no poles at real momenta. It turns out that for charged pions and kaons, the contribution of intermediate scalar fields to polarizability is substantial, but not the largest one. The calculated polarizabilities are in reasonable agreement with COMPASS experimental data and results of Chiral Perturbation Theory.

   hep-phPRD(2023)·3 citations
7. 07*

   Basis light-front quantization approach to $\Lambda$ and ${\Lambda }_c$ and their isospin triplet baryons

   Tiancai Peng🇨🇳 · Zhimin Zhu🇨🇳 · Siqi Xu🇨🇳 · Xiang Liu🇨🇳 · Chandan Mondal🇨🇳 · Xingbo Zhao🇨🇳 · James P. Vary🇺🇸

   We obtain the masses, the electromagnetic properties, and the parton distribution functions (PDFs) of $\Lambda$, ${\Lambda }_c$, and their isospin triplet baryons, i.e, ${\Sigma }^0$, ${\Sigma }^{+}$, ${\Sigma }^{-}$ and ${\Sigma }_c^0$, ${\Sigma }_c^{+}$, ${\Sigma }_c^{++}$ from a light-front effective Hamiltonian in the leading Fock sector in the basis light-front quantization framework. The light-front wave functions of these baryons are given by the eigenstates of the effective Hamiltonian consisting of a three-dimensional confinement potential and a one-gluon exchange interaction with fixed coupling. The masses of these baryons in our approach are in the experimental range while isospin-dependent mass differences are too small. Meanwhile, the electromagnetic properties are in agreement with the available experimental data, the lattice QCD simulations, and the other theoretical calculations. We also present the gluon and the sea quark PDFs, which we generate dynamically from the QCD evolution of the valence quark distributions.

   hep-phPRD(2022)·25 citations
8. 08*

   Bayesian inference of the fluctuating proton shape in DIS and hadronic collisions

   Heikki Mäntysaari🇫🇮 · Björn Schenke🇺🇸 · Chun Shen🇺🇸 · Wenbin Zhao🇺🇸

   We determine the likelihood distribution for the model parameters describing the event-by-event fluctuating proton geometry at small $x$ by performing a Bayesian analysis within the Color Glass Condensate framework. The exclusive $\mathrm{J}/\psi$ production data from HERA is found to constrain the model parameters well, and we demonstrate that complementary constraints can be obtained from simulations of Pb+Pb collisions at the LHC.

   hep-phnucl-thActa Phys.Polon.Supp.(2023)·3 citations
9. 09*

   Prospects for probing axionlike particles at a future hadron collider through top quark production

   Yasaman Hosseini🇮🇷 · Mojtaba Mohammadi Najafabadi🇮🇷

   Axionlike particles (ALPs) emerge from spontaneously broken global symmetries in high energy extensions of the Standard Model (SM). This causes ALPs to be among the objectives of future experiments which intend to search for new physics beyond the SM. We discuss the reach of future pp collider FCC-hh in probing the ALP model parameters through top quark pair production associated with ALP ($t\bar{t}+\text{ALP}$) in a model-independent approach. The search is performed in the semileptonic decay mode of $t\bar{t}$ and the analysis is performed using a parametric simulation of the detector response for a projected integrated luminosity of $30\mathrm{a}{\mathrm{b}}^{-1}$. It is shown that $t\bar{t}+\text{ALP}$ production at the FCC-hh is a promising channel with significant sensitivity to probe the ALP coupling with gluons. The ALP coupling with gluons obtained from HL-LHC and other experiments are presented for comparison.

   hep-phUniverse(2022)·5 citations
10. 10*

    Blast from the past II: Constraints on heavy neutral leptons from the BEBC WA66 beam dump experiment

    Ryan Barouki🇬🇧 · Giacomo Marocco🇬🇧 · Subir Sarkar🇬🇧

    We revisit the search for heavy neutral leptons with the Big European Bubble Chamber in the 1982 proton beam dump experiment at CERN, focussing on those heavier than the kaon and mixing only with the tau neutrino, as these are far less constrained than their counterparts with smaller mass or other mixings. Recasting the previous search in terms of this model and including additional production and decay channels yields the strongest bounds to date, up to the tau mass. This applies also to our updated bounds on the mixing of heavy neutral leptons with the electron neutrino.

    hep-phSciPost Phys.(2022)·87 citations
11. 11*

    Flavor Changing Neutral Current processes and family discrimination in 3-3-1 models

    Vinícius Oliveira🇧🇷 · C. A. de S. Pires🇧🇷

    In 3-3-1 models anomaly cancellation requires that one of the three families of quarks transforms as triplet by $\text{SU}(3{)}_{\text{L}}$ with the other two transforming necessarily as anti-triplet. This is an important feature of the model because with it we explain family replication. Thus it is mandatory to discriminate which of the families will transform as triplet by $\text{SU}(3{)}_{\text{L}}$ because the main consequence of anomaly cancellation in 3-3-1 models is the arising of processes violating flavor at tree level by means of neutral currents mediated by gauge and scalar fields and each case leads to different results. In this work we consider the 3-3-1 model with right-handed neutrinos. Among the spectrum of 3-3-1 particles that contributes to the flavor changing neutral processes, there is a pseudoscalar that may be the lightest of the 3-3-1 particles and then should give the main contribution to such processes. We then calculate its contribution to the $K^0-{\bar{K}}^0$ mixing transition and confront it with the current experimental results. We do this for the three cases in which one of the family of quarks transforms as a triplet by $\text{SU}(3{)}_{\text{L}}$. According to our findings each case leads to different constraints on the mass of the pseudoscalar and the case in which the third family of quarks transforms as triplet seems to be the favoured one. We also obtain the most stringent bounds on the mass of the pseudoscalar of the model.

    hep-phJ.Phys.G(2023)·25 citations
12. 12*

    Crafting polarisations for top, $W$ and $Z$

    J. A. Aguilar-Saavedra🇪🇸

    We put forward a method to tune the polarisation state of decaying heavy particles (top quarks and $W/Z$ bosons) in a pre-existing Monte Carlo sample. With this technique, dubbed as `custom angle replacement', the decay angular distributions are modified in such a way that the desired polarisation state is reproduced, while all the production kinematics are unchanged. A non-trivial test of this approach is presented for the top quark semileptonic decay $t\to Wb\to \ell \nu b$, with $\ell =e,\mu$, in which the decay distribution is four-dimensional and involves three different Lorentz frames. The proposed method is ideally suited to obtain event samples with polarised heavy particles, as required by experimental measurements of polarisation and spin correlations.

    hep-phhep-exPRD(2022)·7 citations
13. 13*

    Effects of Reheating on Moduli Stabilization

    Khursid Alam🇮🇳 · Koushik Dutta🇮🇳

    Moduli potential loses its minima due to external energy sources of inflaton energy density or radiation produced at the end of inflation. But, the non-existence of minima does not necessarily mean destabilization of moduli. In fact, the destabilization of moduli is always dependent on the initial field values of the fields. In this work, we study carefully how the effects of reheating ease the problem of moduli destabilization. The associated time scale to produce the thermal bath allows a larger initial field range to stabilize the field. Contrary to the usual notion, the allowed initial field range is larger for higher temperatures when the effective potential is of a run-away nature. This eases the moduli destabilization problem for heavy mass moduli. For low mass moduli ($\lesssim$ 30 TeV), the allowed field range still causes the cosmological moduli problem by violating the BBN constraints unless its initial abundance is suppressed.

    hep-phastro-ph.COgr-qchep-thJCAP(2022)·5 citations
14. 14*

    Baryonic spin Hall effects in Au+Au collisions at $\sqrt{s_{NN}}=7.7-200$ GeV

    Baochi Fu🇨🇳 · Longgang Pang🇨🇳 · Huichao Song🇨🇳 · Yi Yin🇨🇳

    In this proceeding, we present our recent prediction on the local net Lambda polarization to search for the baryonic spin Hall effect (SHE) at RHIC BES energies. The baryonic SHE is induced by the gradients of baryon chemical potential, which leads to local polarization separation between baryons and anti-baryons. Based on hydrodynamic simulations with spin Cooper-Fryer formula, we propose to use $P_{2,y}^{\mathrm{net}}$ and $P_{2,z}^{\mathrm{net}}$, the second Fourier coefficients of net spin polarization to quantify this baryonic SHE. Future experimental observation of their non-trivial signatures could strongly support the existence of the baryon SHE in hot and dense QCD matter.

    hep-phActa Phys.Polon.Supp.(2023)·7 citations
15. 15*

    A Scotogenic Model with Two Inert Doublets

    Amine Ahriche (U. Sharjah)🇮🇹

    In this work, we present a scotogenic model, where the neutrino mass is generated at one-loop diagrams. The standard model (SM) is extended by three singlet Majorana fermions and two inert scalar doublets instead of one doublet as in the minimal scotogenic model. The model scalar sector includes two CP-even, two CP-odd and two charged scalars in addition to the Higgs. The dark matter (DM) candidate could be either the light Majorana fermion (Majorana DM), or the lightest among the CP-even and the CP-odd scalars (scalar DM). We show that the model accommodates both Majorana and scalar DM within a significant viable parameter space, while considering all the relevant theoretical and experimental constraints such as perturbativity, vacuum stability, unitarity, the di-photon Higgs decay, electroweak precision tests and lepton flavor violating constraints. In addition to the collider signatures predicted by the minimal scotogenic model, our model predicts some novel signatures that can be probed through some final states such as $8jets+\text{slashed}{E}_T$, $1\ell +4jets+\text{slashed}{E}_T$ and $4b+\text{slashed}{E}_T$.

    hep-phJHEP(2023)·13 citations
16. 16*

    Searches for Lorentz and CPT Violation with Confined Particles

    Yunhua Ding🇺🇸

    An overview of recent progress on searches for Lorentz- and CPT-violating signals with confined particles and antiparticles in Penning traps is presented. In the context of the Standard-Model Extension (SME), leading-order shifts in the cyclotron and anomaly frequencies of a confined particle and antiparticle due to Lorentz and CPT violation are provided. The two frequencies are then related to comparisons of charge-to-mass ratios and magnetic moments between particles and antiparticles. Applying reported results from Penning-trap experiments leads to new limits on various coefficients for Lorentz violation.

    hep-ph0 citations
17. 17*

    Constraining the photon mass via Schumann resonances

    P. C. Malta · J. A. Helayël-Neto🇧🇷

    The photon is the paradigm for a massless particle and current experimental tests set severe upper bounds on its mass. Probing such a small mass, or equivalently large Compton wavelength, is challenging at laboratory scales, but planetary or astrophysical phenomena may potentially reach much better sensitivities. In this work we consider the effect of a finite photon mass on Schumann resonances in the Earth-ionosphere cavity, since the TM modes circulating Earth have eigen-frequencies of order $\mathcal{O}(10\mathrm{Hz})$ that could be sensitive to $m_{\gamma }\approx 10^{-14}{eV/c}^2$. In particular, we update the limit from Kroll [Phys. Rev. Lett. 27, 340 (1971)], $m_{\gamma }\le 2.4\times 10^{-13}{eV/c}^2$, by considering realistic conductivity profiles for the atmosphere. We find the conservative upper bound $m_{\gamma }\le 2.5\times 10^{-14}{eV/c}^2$, a factor 9.6 more strict than Kroll's earlier projection.

    hep-phphysics.ao-phphysics.geo-phPRD(2022)·7 citations
18. 18*

    The factorization effect in ${\Lambda }_C\to \Lambda \pi$ and ${\Lambda }_C\to \Lambda K$

    Shou-shan Bao🇨🇳

    We calculated the branch ratios of ${\Lambda }_C\to \Lambda K$ and ${\Lambda }_C\to \Lambda \pi$ within factorization approximation. It is found that the results suffers from the uncertainties of form factors. To reduce such uncertainties, we checked the ratio of the two channels, which is obtained as $R=0.0743\pm 0.0014$. It is found that the uncertainty caused by form factors is significantly reduced. This note is prepared for the BESIII collaboration.

    hep-ph1 citation
19. 19*

    Electroweak production of ${\chi }_{Q1}$ states in $e^{+}{e}^{-}$ collisions: A brief review

    N.N. Achasov🇷🇺 · A.V. Kiselev🇷🇺 · G.N. Shestakov🇷🇺

    A brief review of the available experimental and theoretical results on the production of the ${\chi }_{Q1}$ states in $e^{+}{e}^{-}$ annihilation and photon-photon $\gamma {\gamma }^{\ast }$ interactions is presented. Future data on the production of the ${\chi }_{c1}(1P)$, ${\chi }_{c1}(3872)$, ${\chi }_{c1}(4140)$, ${\chi }_{c1}(4274)$, ${\chi }_{c1}(4685)$, ${\chi }_{b1}(1P)$, ${\chi }_{b1}(2P)$, and ${\chi }_{b1}(3P)$ resonances in $e^{+}{e}^{-}$ annihilation and $\gamma {\gamma }^{\ast }$ interactions will help the development and unification of theoretical predictions related to the electroweak decays of heavy quarkonia, the reduction of their spread and model uncertainties.

    hep-phhep-exnucl-exnucl-thPRD(2022)·10 citations
20. 20*

    The role of initial state radiation in quenched jets

    Korinna Zapp🇸🇪

    Jet quenching in heavy ion collisions and in particular the sub-structure of quenched jets are promising tools for investigating the microscopic processes underlying jet quenching and the background medium's response to energy and momentum depositions. A quantitative understanding of the data can, however, be complicated by the presence of initial state radiation in reconstructed jets. Using an extended version of JEWEL the effect of initial state radiation on different jet observables is studied in proton-proton and heavy ion collisions. It is shown that, depending on the observable and the jet radius, the initial state contributions can be sizable. Some general insights into when sizable effects can be expected also emerges.

    hep-phnucl-thPLB(2022)·5 citations
21. 21*

    Comments and extensions of a suggestion for a relativistic charge density definition

    Carl E. Carlson (William & Mary)🇺🇸

    A recent suggested definition of a relativistically correct three dimensional charge density of an extended hadron is shown to be physically and intuitively connected to an earlier relativistically correct two dimensional charge density studied in the context of light-front physics. Looking at spin-1/2 hadrons, such a connection is shown to exist for both the polarized and unpolarized cases.

    hep-phnucl-th11 citations
22. 22*

    Rare radiative ${\Xi }_b^{-}\to {\Xi }^{-}\gamma$ decay in the relativistic quark model

    A. O. Davydov🇷🇺 · R. N. Faustov🇷🇺 · V. O. Galkin🇷🇺

    Recently the LHCb collaboration put the upper limit on the ${\Xi }_b^{-}\to {\Xi }^{-}\gamma$ decay branching ratio $Br({\Xi }_b^{-}\to {\Xi }^{-}\gamma )<1.3\times 10^{-4}$. The measured value is below the light-cone sum rule prediction. In this paper the rare radiative decay of the ${\Xi }_b^{-}$ baryon is studied in the framework of the relativistic quark model based on the quasipotential approach and QCD. The decay form factors are calculated with the comprehensive account of the relativistic effects. The obtained result for the branching ratio is found to be below the upper limit set by LHCb and is consistent with theoretical predictions based on the SU(3) flavor-symmetry, light-front quark model and light-cone QCD sum rules in full theory within theoretical uncertainties.

    hep-phMod.Phys.Lett.A(2022)·4 citations
23. 23*

    Photons production in heavy-ion collisions as a signal of deconfinement phase

    Sergei Nedelko🇷🇺 · Aleksei Nikolskii🇷🇺

    The photon production due to conversion of two gluons into a photon, $gg\to \gamma$, in the presence of the background gauge fields is studied within the specific mean-field approach to QCD vacuum. In this approach, mean field in the confinement phase is represented by the statistical ensemble of almost everywhere homogeneous abelian (anti-)self-dual gluon configurations, while the deconfined phase can be characterized by the purely chromomagnetic fields. The probability of gluon conversion of two gluons into a photon vanishes in the confinement phase due to the randomness of the background field configurations. The anisotropic strong electromagnetic field, generated in the collision of relativistic heavy ions, serves as a catalyst for deconfinement with the appearance of an anisotropic purely chromomagnetic mean field. Respectively, deconfined phase is characterized by nonzero probability of the conversion of two gluons into a photon with strongly anisotropic angular distribution.

    hep-phEPJA(2023)·5 citations
24. 24*

    WIMP and FIMP Dark Matter in Singlet-Triplet Fermionic Model

    Geneviève Bélanger🇫🇷 · Sandhya Choubey🇸🇪 · Rohini M. Godbole🇮🇳 · Sarif Khan🇩🇪 · Manimala Mitra🇮🇳 · Abhishek Roy🇮🇳

    We present an extension of the SM involving three triplet fermions, one triplet scalar and one singlet fermion, which can explain both neutrino masses and dark matter. One triplet of fermions and the singlet are odd under a $Z_2$ symmetry, thus the model features two possible dark matter candidates. The two remaining $Z_2$-even triplet fermions can reproduce the neutrino masses and oscillation parameters consistent with observations. We consider the case where the singlet has feeble couplings while the triplet is weakly interacting and investigate the different possibilities for reproducing the observed dark matter relic density. This includes production of the triplet WIMP from freeze-out and from decay of the singlet as well as freeze-in production of the singlet from decay of particles that belong to the thermal bath or are thermally decoupled. While freeze-in production is usually dominated by decay processes, we also show cases where the annihilation of bath particles give substantial contribution to the final relic density. This occurs when the new scalars are below the TeV scale, thus in the reach of the LHC. The next-to-lightest odd particle can be long-lived and can alter the successful BBN predictions for the abundance of light elements, these constraints are relevant in both the scenarios where the singlet or the triplet are the long-lived particle. In the case where the triplet is the DM, the model is subject to constraints from ongoing direct, indirect and collider experiments. When the singlet is the DM, the triplet which is the next-to-lightest odd particle can be long-lived and can be probed at the proposed MATHUSLA detector. Finally we also address the detection prospects of triplet fermions and scalars at the LHC.

    hep-phJHEP(2022)·17 citations
25. 25*

    BEEC2.0: An Upgraded Version for the Production of Heavy Quarkonium at Electron-positron Collider

    Zhi Yang🇨🇳 · Xu-Chang Zheng🇨🇳 · Xing-Gang Wu🇨🇳

    The event generator BEEC [Z. Yang, X.G. Wu and X.Y. Wang, Comput. Phys. Commun. 184, 2848 (2013)] was devoted to the simulation of heavy quarkonium production at an unpolarized electron-positron collider. We upgraded it here by adding the generation of quarkonium with polarized electron and positron beams. In addition, the production of color-singlet 2S-wave states were included. Several future electron-positron colliders with high luminosity have been under discussion in the past decade. Especially, their possibility of producing polarized beams is important for providing more insights into the underlying physics. This upgraded version offers a useful tool for the feasibility study on quarkonium from the experimental side.

    hep-phhep-exComput.Phys.Commun.(2022)·6 citations
26. 26*

    Multi-hadron molecules: status and prospect

    Tian-Wei Wu🇨🇳 · Ya-Wen Pan🇨🇳 · Ming-Zhu Liu🇨🇳 · Li-Sheng Geng🇨🇳

    Starting from 2003, the discovery of a large amount of the so-called exotic hadronic states, i.e., the $XYZ$ states, the pentaquark states as well as the tetraquark states, have not only revived studies of hadron spectroscopy, but also hinted at the existence of new multi-hadron states made of hadrons other than nucleons and hyperons. We briefly comment on some of the latest studies on multi-hadron molecules in the light and heavy flavor sectors and highlight what should be done in the future.

    hep-phhep-exhep-latnucl-ex+1Sci.Bull.(2022)·30 citations
27. 27*

    Second resonance of the Higgs field: more signals from the LHC experiments

    Maurizio Consoli🇮🇹 · Leonardo Cosmai🇮🇹 · Fabrizio Fabbri🇮🇹

    Theoretical arguments and lattice simulations suggest that, beside the known resonance of mass $m_h=$ 125 GeV, the Higgs field might exhibit a second resonance with a larger mass $(M_H{)}^{\mathrm{theor}}=690\pm 10(\mathrm{stat})\pm 20(\mathrm{sys})\mathrm{GeV}$ which, however, would couple to longitudinal W's with the same typical strength as the low-mass state at 125 GeV and thus represent a relatively narrow resonance mainly produced at LHC by gluon-gluon fusion. By looking for some evidence in the LHC data, we argue that the existence of a new resonance in the predicted mass region finds support in two analyses by ATLAS (searching for heavy resonances decaying into final states with 4 charged leptons or $\gamma \gamma$ pairs) and in more recent CMS results (searching for heavy resonances decaying into a pair of $h(125)$ bosons or looking for $\gamma \gamma$ pairs produced in $pp$ double-diffractive scattering). Since the correlation of these measurements is very small and since, having some definite theoretical prediction, local deviations from the pure background are not downgraded by the look-elsewhere effect, we emphasize the instability of the present situation that could probably be resolved by just adding two crucial, missing samples of RUN2 data.

    hep-ph8 citations
28. 28*

    Power Corrections to Electroweak Boson Production from Threshold Resummation

    George Sterman🇺🇸 · Werner Vogelsang🇩🇪

    We study the power corrections for electroweak boson production that are implied by threshold resummation, which we have extended to massive particles produced at measured transverse momentum, $p_T$, and rapidity. Power corrections in the resulting expressions arise from ambiguities in the low-scale behavior of the perturbative running coupling. Arguing for the relevance of the eikonal approximation, we show that such power corrections begin at order $1/p_T^2$ in full QCD, consistent with fixed-order, massive-gluon analysis. For large-$N$ Mellin moments, the leading behavior is $N^2/p_T^2$, which exponentiates along with the logarithms of threshold resummation.

    hep-phPRD(2023)·10 citations
29. 29*

    Lattice three-gluon vertex in extended kinematics: planar degeneracy

    F. Pinto-Gómez🇪🇸 · F. De Soto🇪🇸 · M. N. Ferreira🇧🇷 · J. Papavassiliou🇪🇸 · J. Rodríguez-Quintero🇪🇸

    We present novel results for the three-gluon vertex, obtained from an extensive quenched lattice simulation in the Landau gauge. The simulation evaluates the transversely projected vertex, spanned on a special tensorial basis, whose form factors are naturally parametrized in terms of individually Bose-symmetric variables. Quite interestingly, when evaluated in these kinematics, the corresponding form factors depend almost exclusively on a single kinematic variable, formed by the sum of the squares of the three incoming four-momenta, $q$, $r$, and $p$. Thus, all configurations lying on a given plane in the coordinate system $(q^2,r^2,p^2)$ share, to a high degree of accuracy, the same form factors, a property that we denominate \emph{planar degeneracy}. We have confirmed the validity of this property through an exhaustive study of the set of configurations satisfying the condition $q^2=r^2$, within the range $[0,5\mathrm{GeV}]$. Moreover, a preliminary exploration reveals that the planar degeneracy persist in the case of more arbitrary configurations. This drastic simplification allows for a remarkably compact description of the main bulk of the data, which is particularly suitable for future numerical applications. A semi-perturbative analysis reproduces the lattice findings rather accurately, once the inclusion of a gluon mass has cured all spurious divergences.

    hep-phhep-latPLB(2023)·36 citations
30. 30*

    Analytic Computation of Three-point Energy Correlator in QCD

    Tong-Zhi Yang🇨🇭 · Xiaoyuan Zhang🇺🇸

    The energy correlator measures the energy deposited in multiple detectors as a function of the angles among them. In this paper, an analytic formula is given for the three-point energy correlator with full angle dependence at leading order in electron-positron annihilation. This is the first analytic computation of trijet event shape observables in QCD, which provides valuable data for phenomenological studies. The result is computed with direct integration, where appropriate parameterizations of both phase space and kinematic space are adopted to simplify the calculation. With full shape dependence, our result provides the expansions in various kinematic regions such as equilateral, triple collinear and squeezed limits, which benefit studies on both factorization and large logarithm resummation.

    hep-phhep-thJHEP(2022)·42 citations
31. 31*

    Quantum color screening in external magnetic field

    Guojun Huang🇨🇳 · Jiaxing Zhao🇨🇳 · Pengfei Zhuang🇨🇳

    We calculate color screening mass in a thermalized and magnetized QCD matter in the frame of loop resummation theory without restriction to the magnetic field strength. Our full calculation covers the often used approximations for weak magnetic field at high temperature and strong magnetic field at low temperature. We find that while the magnetic field created in heavy ion collisions at RHIC and LHC energies is probably the strongest one in nature, its effect on the QCD matter is still weaker in comparison with the high temperature of the fireball, and therefore can safely be treated as a perturbation.

    hep-phhep-thPRD(2023)·10 citations
32. 32*

    Light baryon resonances from a coupled-channel study including $\mathbf{K\Sigma }$ photoproduction

    Deborah Rönchen🇩🇪 · Michael Döring🇺🇸 · Ulf-G. Meißner🇩🇪 · Chao-Wei Shen🇩🇪

    The Jülich-Bonn dynamical coupled-channel approach is extended to include $K\Sigma$ photoproduction off the proton. Differential cross section and (double) polarization data for $K^{+}{\Sigma }^0$ and $K^0{\Sigma }^{+}$ are analysed simultaneously with the pion- and photon-induced production of $\pi N$, $\eta N$, $K\Lambda$, and $K\Sigma$ final states, totaling more than 67,000 data points for center-of-mass energies $W<2.4$ GeV. Based on the fit results the spectrum of $N^{\ast }$ and $\Delta$ resonances is extracted in terms of pole positions and residues. We discuss the impact of the $\gamma p\to K\Sigma$ channels in detail and investigate the influence of recent polarization data for $\eta p$ photoproduction.

    ↳ nucl-thhep-phnucl-exEPJA(2022)·55 citations
33. 33*

    Gravity Tests with Radio Pulsars in Perturbative and Nonperturbative Regimes

    Lijing Shao🇨🇳

    Searches for empirical clues beyond Einstein's general relativity (GR) are crucial to understand gravitation and spacetime. Radio pulsars have been playing an important role in testing gravity theories since 1970s. Because radio timing of binary pulsars is very sensitive to changes in the orbital dynamics, small deviations from what GR predicts can be captured or constrained. In this sense, the gravity sector in the standard-model extension was constrained tightly with a set of pulsar systems. Moreover, compact objects like pulsars are possible to develop nonperturbative deviations from GR in some specific alternative gravity theories, thus radio pulsars also provide rather unique testbeds in the strong-gravity regime.

    ↳ gr-qcastro-ph.HEhep-phProceedings of the Ninth Meeting on CPT a…·2 citations
34. 34*

    Dark energy: EFTs and supergravity

    Francesc Cunillera🇬🇧

    The subject of this thesis is cosmological implications of string compactifications understood in a broad sense. In the first half of the thesis, we will begin by reviewing the four-dimensional description of the tree-level perturbative type IIB action. We will then review a number of open questions in cosmology and their relevance with regards to the remainder of the thesis. We will first explore some of these cosmological questions from the perspective of effective field theories motivated by supergravity. From the naturalness of dark energy and how to obtain a naturally light dark energy field in terms of the clockwork mechanism and the Dvali-Kaloper-Sorbo four-form mixing. We also discuss the coincidence problem for dynamical models of dark energy consistent with a quintessence field slowly rolling down a potential slope, of the type one would expect from the asymptotics of moduli space. In the second half of the thesis, we introduce the effects of perturbative and non-perturbative corrections to the tree-level type IIB action. We then focus on obtaining a viable model of quintessence from the type IIB effective field theory. However, we are able to show that such a model must have a non-supersymmetric Minkowski vacuum at leading order. When we consider the effects of quantum fluctuations during the early Universe, we see that such models must have extremely fine-tuned initial conditions to describe a slow-rolling scalar field at present times. We conclude that quintessence faces more challenges than a true cosmological constant, to the point that quintessence is very unattractive for model building modulo a ruling out of the cosmological constant by observations. Following this line of reasoning, we consider whether other perturbative corrections can generate de Sitter solutions in an appropriate setting.

    ↳ hep-thastro-ph.COgr-qchep-ph2 citations
35. 35*

    Impact of Symmetry Energy on Sound Speed and Spinodal Decomposition in Dense Neutron-Rich Matter

    Nai-Bo Zhang🇨🇳 · Bao-An Li🇺🇸

    Using a meta model for nuclear Equation of State (EOS) with its parameters constrained by astrophysical observations and terrestrial nuclear experiments, we examine effects of nuclear EOS especially its symmetry energy \esym term on the speed of sound squared $C_s^2(\rho )$ and the critical density ${\rho }_t$ where $C_s^2({\rho }_t)$ vanishes (indicating the onset of spinodal decomposition) in both dense neutron-rich nucleonic matter relevant for relativistic heavy-ion collisions and the cold $n+p+e+\mu$ matter in neutron stars at $\beta$-equilibrium. Unlike in nucleonic matter with fixed values of the isospin asymmetry $\delta$, in neutron stars with a density dependent isospin profile $\delta (\rho )$ determined consistently by the $\beta$ equilibrium and charge neutrality conditions, the $C_s^2(\rho )$ almost always show a peak and then vanishes at ${\rho }_t$. The latter strongly depends on the high-density behavior of \esym if the skewness parameter $J_0$ characterizing the stiffness of high-density symmetric nuclear matter (SNM) EOS is not too far above its currently known most probable value of about $-190$ MeV inferred from recent Bayesian analyses of neutron star observables. Moreover, in the case of having a super-soft \esym that is decreasing with increasing density above about twice the saturation density of nuclear matter, the ${\rho }_t$ is significantly lower than the density where the \esym vanishes (indicating the onset of isospin-separation instability and pure neutron matter formation) in neutron star cores.

    ↳ nucl-thastro-ph.HEhep-phnucl-exEPJA(2023)·30 citations
36. 36*

    Constraining Axions with ZTF J1901+1458

    Leesa Fleury🇨🇦 · Ilaria Caiazzo🇺🇸 · Jeremy Heyl🇨🇦

    The axion-nucleon coupling enables the production of axions through the decay of excited ${}^{57}\text{Fe}$ isotopes, and axions produced in the Sun through this process are often a target of helioscope searches. We show for the first time that hot, highly magnetic white dwarfs such as ZTF J1901+1458 are a viable target to search for the X-ray signature of axions that were produced by the ${}^{57}\text{Fe}$ transition in the core and then converted to photons in the magnetosphere. We calculate that a 100 ks observation of ZTF J1901+1458 with NuSTAR would constrain the coupling of axions to nucleons and photons at a level below the bounds of both current and future planned helioscopes.

    ↳ astro-ph.HEastro-ph.SRhep-phPRD(2023)·6 citations
37. 37*

    Momentum gauge fields from curved momentum space through Kaluza-Klein reduction

    Eduardo Guendelman🇮🇱 · Fabian Wagner🇵🇱

    In this work we investigate the relation between curved momentum space and momentum-dependent gauge fields. While the former is a classic idea that has been shown to be tied to minimal-length models, the latter constitutes a relatively recent development in quantum gravity phenomenology. In particular, the gauge principle in momentum space amounts to a modification of the position operator of the form ${\hat{X}}^{\mu }\to {\hat{X}}^{\mu }-g{A}^{\mu }(\hat{P})$ akin to a gauge-covariant derivative in momentum space according to the minimal coupling prescription. Here, we derive both effects from a Kaluza-Klein reduction of a higher-dimensional geometry exhibiting curvature in momentum space. The interplay of the emerging gauge fields as well as the remaining curved momentum space lead to modifications of the Heisenberg algebra. While the gauge fields imply Moyal-type noncommutativity dependent on the analogue field strength tensor, the dimensionally reduced curved momentum space geometry translates to a Snyder-type noncommutative geometry.

    ↳ gr-qchep-phhep-thquant-phClass.Quant.Grav.(2023)·8 citations
38. 38*

    Quark Matter in the NJL Model with a Vector Interaction and the Structure of Hybrid Stars

    G. B. Alaverdyan🇦🇲

    The properties of hadron-quark hybrid stars are studied when the quark phase is described in terms of a local SU(3) Nambu--Jona-Lasinio (NJL) model taking into account the contribution of the vector and axial-vector interaction between the quarks, and the hadronic phase, in the relativistic mean field (RMF) model. For different values of the vector coupling constant $G_V$, the equations of state of the quark matter are calculated and the parameters of the hadron-quark phase transition are determined under the assumption that the phase transition takes place in accordance with Maxwell's construction. It is shown that for a larger vector coupling constant, the equation of state of the quark matter will be "stiffer" and the coexistence pressure $P_0$ of the phases will be greater. Using the resulting hybrid equations of state, the TOV equations are integrated numerically and the mass and radius of the compact star are determined for different values of the central pressure $P_c$. It is shown that when $G_V$ is larger, the maximum mass of the compact star will be larger and thereby, the radius of the configuration with maximum mass will be smaller. Questions of the stability of hybrid stars are also discussed. It is shown that in terms of the model examined here, for all values of the vector coupling constant, a hybrid star with an infinitely small quark core is stable. These results are compared with recent measurements of the mass and radius of the pulsars PSR J0030+0451 and PSR J0740+6620, carried out at the International Space Station with the NASA's Neutron star Interior Composition Explorer (NICER) X-ray telescope. A comparison of the theoretical results with observational data does not exclude the possibility of quark deconfinement in the interiors of compact stars.

    ↳ nucl-thastro-ph.SRhep-phAstrophysics(2022)·12 citations
39. 39*

    Effect of global momentum conservation on longitudinal flow decorrelation

    Pingal Dasgupta🇨🇳 · Han-Sheng Wang🇨🇳 · Guo-Liang Ma🇨🇳

    We calculate the longitudinal flow decorrelation coefficients, i.e., $r_n(\eta ,{\eta }_r)$ for $n=2,3$, in the presence of hydro-like flow and the global momentum conservation (GMC) constraint. The longitudinal flow decorrelation is weakened due to the GMC constraint. The GMC effect is sensitive to the total number of particles involved in GMC, the average longitudinal momentum, the transverse momentum, and the reference pseudorapidity. Our results of the $r_2(\eta ,{\eta }_{rA})/r_2(\eta ,{\eta }_{rB})$ ratio between two reference pseudorapidity bins are consistent with the experimental measurements. We predict that the modification effect of GMC on longitudinal flow decorrelation is more noticeable at BNL Relativistic Heavy Ion Collider energies than at CERN Large Hadron Collider energies. Our finding provides a new perspective for understanding the longitudinal flow decorrelation in relativistic heavy-ion collisions.

    ↳ nucl-thhep-phnucl-exPRC(2023)·4 citations
40. 40*

    A New Structure in the Deuteron

    Misak M. Sargsian🇺🇸 · Frank Vera🇺🇸

    We demonstrate that a paradigm shift from considering the deuteron as a system of bound proton and neutron to considering it as a pseudo-vector system in which we observe proton and neutron, results in a possibility of probing a new "incomplete" P-state like structure on the light-front (LF), at extremely large internal momenta, which can be achieved in high energy transfer electro-disintegration of the deuteron. Investigating the deuteron on the light-front, where the vacuum-fluctuations are suppressed, we found that this new structure, together with conventional S- and D- states, is a leading order in transferred energy of the reaction, thus it is not suppressed on the light-front.The incompleteness of the observed P-state results in a violation of angular condition which can happen only if deuteron contains non-nucleonic structures such as $\Delta$$\Delta$, $N^{\ast }N$ or hidden color components. We demonstrate that experimentally verifiable signatures of "incomplete" P-states are angular anisotropy of LF momentum distribution of the nucleon in the deuteron as well as an enhancement of the tensor polarization strength beyond the S- and D- wave predictions at large internal momenta in the deuteron.

    ↳ nucl-thhep-phnucl-exPRL(2023)·14 citations
41. 41*

    Non-equilibrium attractor in high-temperature QCD plasmas

    Dekrayat Almaalol🇺🇸 · Kirill Boguslavski🇦🇹 · Aleksi Kurkela🇳🇴 · Michael Strickland🇺🇸

    We establish the existence of a far-from-equilibrium attractor in weakly-coupled gauge theory undergoing 0+1d Bjorken expansion which goes beyond the energy-momentum tensor to the detailed form of the one-particle distribution function. We then demonstrate that the dynamics can be re-scaled at intermediate times and represented by universal exponents. Finally, we assess different procedures for reconstructing the full one-particle distribution function from the energy-momentum tensor along the attractor and discuss implications for the freeze-out procedure used in the phenomenological analysis of ultra-relativistic nuclear collisions

    ↳ hep-thhep-phnucl-th2 citations
42. 42*

    Pion, kaon, and (anti-)proton production in U+U Collisions at $\sqrt{s_{NN}}$ = 193 GeV measured with the STAR detector

    STAR Collaboration: M. S. Abdallah🇪🇬 · B. E. Aboona🇺🇸 · J. Adam🇺🇸 · J. R. Adams🇺🇸 · J. K. Adkins🇺🇸 · G. Agakishiev🇷🇺 · I. Aggarwal🇮🇳 · M. M. Aggarwal🇮🇳 · Z. Ahammed🇮🇳 · A. Aitbaev🇷🇺 · I. Alekseev🇷🇺 · D. M. Anderson🇺🇸 and 342 other authors

    We present the first measurements of transverse momentum spectra of ${\pi }^{\pm }$, $K^{\pm }$, $p(\bar{p})$ at midrapidity ($|y|<0.1$) in U+U collisions at $\sqrt{s_{NN}}$ = 193 GeV with the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The centrality dependence of particle yields, average transverse momenta, particle ratios and kinetic freeze-out parameters are discussed. The results are compared with the published results from Au+Au collisions at $\sqrt{s_{NN}}=$ 200 GeV in STAR. The results are also compared to those from A Multi Phase Transport (AMPT) model.

    ↳ nucl-exhep-exhep-phnucl-thPRC(2023)·18 citations
43. 43*

    Implications for Cosmic Domain Walls from LIGO-Virgo First Three Observing Runs

    Yang Jiang🇨🇳 · Qing-Guo Huang🇨🇳

    We put constraints on the normalized energy density in gravitaional waves from cosmic domain walls (DWs) by searching for the stochastic gravitational-wave background (SGWB) in the data of Advanced LIGO and Virgo's first three observing runs. By adopting a phenomenological broken power-law model, we obtain the upper limit of normalized energy density of SGWB generated by DWs in the peak frequency band $10\sim 200$ Hz, and get the most stringent limitation at the peak frequency $f_{\ast }=35$ Hz, namely ${\Omega }_{\text{DW}}(f_{\ast }=35\text{Hz})<1.4\times 10^{-8}$ at $95\%$ confidence level (CL). Subsequently, we work out the constraints on the parameter space in the appealing realization of DW structure -- the heavy axion model which can avoid the so-called quality problem.

    ↳ astro-ph.COhep-phhep-thPRD(2022)·15 citations
44. 44*

    Far-from-equilibrium attractor in non-conformal plasmas

    Sunil Jaiswal🇮🇳 · Subrata Pal🇮🇳 · Chandrodoy Chattopadhyay🇺🇸 · Lipei Du🇨🇦 · Ulrich Heinz🇺🇸

    We study the far-off-equilibrium dynamics of a Bjorken expanding non-conformal system within kinetic theory and hydrodynamics. We show that, in contrast to the conformal case, neither shear nor bulk viscous pressure relax quickly to a non-equilibrium attractor. In kinetic theory an early-time, far-from-equilibrium attractor exists for the scaled longitudinal pressure, driven by the rapid longitudinal expansion of the medium. Second-order dissipative hydrodynamics fails to accurately describe this attractor, but a modified anisotropic hydrodynamic formulation reproduces it and provides excellent agreement with kinetic theory.

    ↳ nucl-thhep-phActa Phys.Polon.Supp.(2023)·6 citations
45. 45*

    Nonperturbatively Renormalized Nucleon Gluon Momentum Fraction in the Continuum Limit of $N_f=2+1+1$ Lattice QCD

    Zhouyou Fan🇺🇸 · Huey-Wen Lin🇺🇸 · Matthew Zeilbeck🇺🇸

    We present the nonperturbatively renormalized nucleon gluon momentum fraction using ensembles with $2+1+1$ flavors of highly improved staggered quarks (HISQ), generated by MILC Collaboration. The calculation is done using clover fermions for the valence action with three pion masses, $220$, $310$ and $690$ MeV and three lattice spacings, 0.09, 0.12, and 0.15 fm. The renormalization is done using RI/MOM nonperturbative renormalization and using cluster-decomposition error reduction (CDER) to enhance the signal-to-noise ratio of the renormalization constant. We find the CDER technique is particularly important to improve the signal at the finer lattice ensembles where the lattice volume is larger. We extrapolate the gluon momentum fraction to the continuum-physical limit and obtain $⟨x{⟩}_g=0.492(52{)}_{\text{stat.+NPR}}(49{)}_{\text{mixing}}$ in the $\overline{\text{MS}}$ scheme at 2 GeV, where first error includes the statistical error and uncertainties in nonperturbative renormalization, while the latter systematic accounts for ignoring quark mixing. Our gluon momentum fraction is consistent with other recent lattice-QCD results at physical pion mass.

    ↳ hep-lathep-phPRD(2023)·16 citations
46. 46*

    Multi-scale evolution of charmed particles in a nuclear medium

    JETSCAPE collaboration: W. Fan🇺🇸 · G. Vujanovic🇺🇸 · S. A. Bass🇺🇸 · A. Majumder🇺🇸 · A. Angerami🇺🇸 · R. Arora🇺🇸 · S. Cao🇺🇸 · Y. Chen🇺🇸 · T. Dai🇺🇸 · L. Du🇨🇦 · R. Ehlers🇺🇸 · H. Elfner🇩🇪 and 47 other authors

    Parton energy-momentum exchange with the quark gluon plasma (QGP) is a multi-scale problem. In this work, we calculate the interaction of charm quarks with the QGP within the higher twist formalism at high virtuality and high energy using the MATTER model, while the low virtuality and high energy portion is treated via a (linearized) Boltzmann Transport (LBT) formalism. Coherence effect that reduces the medium-induced emission rate in the MATTER model is also taken into account. The interplay between these two formalisms is studied in detail and used to produce a good description of the D-meson and charged hadron nuclear modification factor RAA across multiple centralities. All calculations were carried out utilizing the JETSCAPE framework.

    ↳ nucl-thhep-phnucl-exPRC(2023)·28 citations
47. 47*

    $ϵ$-Expansion of Multivariable Hypergeometric Functions Appearing in Feynman Integral Calculus

    Souvik Bera🇮🇳

    We present a new methodology, suitable for implementation on computer, to perform the $ϵ$-expansion of hypergeometric functions with linear $ϵ$ dependent Pochhammer parameters in any number of variables. Our approach allows one to perform Taylor as well as Laurent series expansion of multivariable hypergeometric functions. Each of the coefficients of $ϵ$ in the series expansion is expressed as a linear combination of multivariable hypergeometric functions with the same domain of convergence as that of the original hypergeometric function. We present illustrative examples of hypergeometric functions in one, two and three variables which are typical of Feynman integral calculus.

    ↳ math-phhep-phhep-thmath.MPNPB(2023)·16 citations
48. 48*

    The Dark Universe after Reheating in String Inflation

    Michele Cicoli🇮🇹 · Kuver Sinha🇺🇸 · Robert Wiley Deal🇺🇸

    We study the production of dark matter and dark radiation after reheating in string inflation models where the Calabi-Yau has a fibred structure and the visible sector lives on D3 branes. We show how the interplay between different physical constraints from inflation, reheating, supersymmetry breaking and dark radiation, leads to distinct predictions for the nature of dark matter.

    ↳ hep-thhep-phJHEP(2022)·25 citations
49. 49*

    Power-law Inflation Satisfies Penrose's Weyl Curvature Hypothesis

    Guido D'Amico🇮🇹 · Nemanja Kaloper🇺🇸

    Based on entropy considerations and the arrow of time Penrose argued that the universe must have started in a special initial singularity with vanishing Weyl curvature. This is often interpreted to be at odds with inflation. Here we argue just the opposite, that Penrose's persuasions are in fact consistent with inflation. Using the example of power law inflation, we show that inflation begins with a past null singularity, where Weyl tensor vanishes when the metric is initially exactly conformally flat. This initial state precisely obeys Penrose's conditions. The initial null singularity breaks $T$-reversal spontaneously and picks the arrow of time. It can be regulated and interpreted as a creation of a universe from nothing, initially fitting in a bubble of Planckian size when it materializes. Penrose's initial conditions are favored by the initial $O(4)$ symmetry of the bubble, selected by extremality of the regulated Euclidean action. The predicted observables are marginally in tension with the data, but they can fit if small corrections to power law inflation kick in during the last 60 efolds.

    ↳ gr-qcastro-ph.COhep-phhep-thPRD(2022)·6 citations
50. 50*

    Monopole-fermion scattering and varying Fock space

    Yuta Hamada🇯🇵 · Teppei Kitahara🇯🇵 · Yoshiki Sato🇯🇵

    We propose a four-dimensional interpretation of the outgoing state of the scattering of a massless fermion off a Dirac monopole. It has been known that such a state has fractional fermion numbers and is necessarily outside the Fock space on top of ordinary perturbative vacuum, when more than two flavours of charged Dirac fermions are considered. In this paper, we point out that the Fock space of the fermions depends on the rotor degree of freedom of the monopole and changes by a monopole-fermion s-wave scattering. By uplifting the fermion-rotor system introduced by Polchinski, from two to four dimensions, we argue that the outgoing state can be understood as a state in a different Fock space.

    ↳ hep-thcond-mat.str-elhep-phJHEP(2022)·20 citations
51. 51*

    Amplitudes within causal loop-tree duality

    Sascha Kromin🇩🇪 · Niklas Schwanemann🇩🇪 · Stefan Weinzierl🇩🇪

    We study scalar one-loop amplitudes in massive ${\varphi }^3$-theory within causal loop-tree duality. We derive a recurrence relation for the integrand of the amplitude. The integrand is by construction free of spurious singularities on H-surfaces. Taking renormalisation and contour deformation into account, we obtain the (integrated) amplitude by Monte Carlo integration. We have checked up to seven points that our results agree with analytic results.

    ↳ hep-thhep-phPRD(2022)·18 citations
52. 52*

    Memories of quenches in operator mixing

    Joydeep Chakrabortty🇮🇳 · Diptarka Das🇮🇳 · Bidyut Dey🇮🇳 · Suraj Prakash🇮🇳 · Shakeel Ur Rahaman🇮🇳

    We work perturbatively with an interacting quantum field theory comprised of two distinct scalar fields. In this theory, we introduce a sudden quench of the mass of one of the scalars at time $t_0$. Also, the quartic interaction between the two scalars is turned on at time $t_{in}$. These break time-translation invariance. In this setup we examine the effects of the relative ordering of $t_0$ and $t_{in}$ on composite operator mixing. We study how such operator mixing affect features of the scalar potential. We find that the late time effective potential can be sensitive enough to the quenches to trigger phase transitions.

    ↳ hep-thcond-mat.stat-mechhep-phPRD(2022)·0 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.