Fri·Dec 13, 2019Friday·December 13, 2019

1. 01*

   Getting a THUMP from a WIMP

   Hooman Davoudiasl🇺🇸 · Gopolang Mohlabeng🇺🇸

   Producing an acceptable thermal relic abundance of dark matter with masses $\gg 10^2$ TeV is a challenge. We propose a novel mechanism where GeV-scale states establish a tiny thermal relic abundance for dark matter, which is later promoted to ultra massive status by a very light scalar. We refer to this dark matter as a THermal Ultra Massive Particle (THUMP). Direct detection of THUMPs can be naturally expected due to large scattering cross sections mediated by low mass states that couple THUMPs to the Standard Model. Our model generically leads to signals for the associated GeV-scale states at accelerator experiments.

   hep-phastro-ph.COJHEP(2020)·28 citations
2. 02*

   Loop Dominated Signals from Neutrino Portal Dark Matter

   Hiren H. Patel🇺🇸 · Stefano Profumo🇺🇸 · Bibhushan Shakya🇨🇭

   We study scenarios where loop processes give the dominant contributions to dark matter decay or annihilation despite the presence of tree level channels. We illustrate this possibility in a specific model where dark matter is part of a hidden sector that communicates with the Standard Model sector via a heavy neutrino portal. We explain the underpinning rationale for how loop processes mediated by the portal neutrinos can parametrically dominate over tree level decay channels, and demonstrate that this qualitatively changes the indirect detection signals in positrons, neutrinos, and gamma rays.

   hep-phastro-ph.COPRD(2020)·18 citations
3. 03*

   T-dependence of the axion mass when the U_A(1) and chiral symmetry breaking are tied

   Dubravko Klabučar🇭🇷 · Davor Horvatić🇭🇷 · Dalibor Kekez🇭🇷

   Modulo the scale of spontaneous breaking of Peccei-Quinn symmetry, the axion mass $m_a(T)$ is given by the QCD topological susceptibility $\chi (T)$ at all temperatures $T$. From an approach tying the $U_A(1)$ and chiral symmetry breaking and getting good $T$-dependence of $\eta$ and $\eta$ mesons, we get $\chi (T)$ for an effective Dyson-Schwinger model of nonperturbative QCD. Comparison with lattice results for $\chi (T)$, and thus also for $m_a(T)$, shows good agreement for temperatures ranging from zero up to the double of the chiral restoration temperature $T_c$.

   hep-phnucl-thActa Phys.Polon.Supp.(2020)·0 citations
4. 04*

   Impact of the Recoil Scheme on the Accuracy of Angular-Ordered Parton Showers

   Silvia Ferrario Ravasio🇬🇧 · Gavin Bewick🇬🇧

   In these proceedings we present three possible interpretations of the ordering variable implemented in the Herwig7 angular-ordered parton shower. Each interpretation determines a different recoil-scheme prescription and we show how it can impact the logarithmic accuracy of the algorithm. We also present comparisons with LEP data.

   hep-phhep-ex0 citations
5. 05*

   New Directions for Axion Searches via Scattering at Reactor Neutrino Experiments

   James B. Dent🇺🇸 · Bhaskar Dutta🇺🇸 · Doojin Kim🇺🇸 · Shu Liao🇺🇸 · Rupak Mahapatra🇺🇸 · Kuver Sinha🇺🇸 · Adrian Thompson🇺🇸

   Searches for pseudoscalar axion-like-particles (ALPs) typically rely on their decay in beam dumps or their conversion into photons in haloscopes and helioscopes. We point out a new experimental direction for ALP probes through their production via the Primakoff process or Compton-like scattering off of electrons or nuclei. We consider ALPs produced by the intense gamma ray flux available from megawatt-scale nuclear reactors at neutrino experiments through Primakoff-like or Compton-like channels. Low-threshold detectors in close proximity to the core will have visibility to ALP decays and inverse Primakoff and Compton scattering, providing sensitivity to the ALP-photon and ALP-electron couplings. We find that the sensitivity to these couplings at the ongoing MINER neutrino experiment exceeds existing limits set by laboratory experiments and, for the ALP-electron coupling, we forecast the world's best laboratory-based constraints over a large portion of the sub-MeV ALP mass range.

   hep-phhep-exPRL(2020)·93 citations
6. 06*

   Quark Transverse Parton Distribution at the Next-to-Next-to-Next-to-Leading Order

   Ming-xing Luo🇨🇳 · Tong-Zhi Yang🇨🇳 · Hua Xing Zhu🇨🇳 · Yu Jiao Zhu🇨🇳

   We report a calculation of the perturbative matching coefficients for the transverse-momentum-dependent parton distribution functions for quark at the next-to-next-to-next-to-leading order in QCD, which involves calculation of non-standard Feynman integrals with rapidity divergence. We introduce a set of generalized Integration-By-Parts equations, which allows an algorithmic evaluation of such integrals using the machinery of modern Feynman integral calculation.

   hep-phnucl-thPRL(2020)·144 citations
7. 07*

   Potential analysis of holographic Schwinger effect in the magnetized background

   Zhou-Run Zhu🇨🇳 · De-fu Hou (CCNU)🇨🇳 · Xun Chen🇨🇳

   We study the holographic Schwinger effect with magnetic field at RHIC and LHC energies by using the AdS/CFT correspondence. We consider both weak and strong magnetic field cases with $B\ll T^2$ and $B\gg T^2$ solutions respectively. Firstly, we calculate separating length of the particle pairs at finite magnetic field. It is found that for both weak and strong magnetic field solutions the maximum value of separating length decreases with the increase of magnetic field , which can be inferred that the virtual electron-positron pairs become real particles more easily. We also find that the magnetic field reduces the potential barrier and the critical field for the weak magnetic field solution, thus favors the Schwinger effect. With strong magnetic field solution, the magnetic field enhances the Schwinger effect when the pairs are in perpendicular to the magnetic field although the magnetic field increases the critical electric field.

   hep-phhep-thnucl-thEPJC(2020)·24 citations
8. 08*

   Bayesian analysis of $b\to s{\mu }^{+}{\mu }^{-}$ Wilson coefficients using the full angular distribution of ${\Lambda }_b\to \Lambda (\to p{\pi }^{-}){\mu }^{+}{\mu }^{-}$ decays

   Thomas Blake (Warwick U.)🇬🇧 · Stefan Meinel (Arizona U.)🇺🇸 · Danny van Dyk (Munich, Tech. U.)🇩🇪

   Following updated and extended measurements of the full angular distribution of the decay ${\Lambda }_b\to \Lambda (\to p{\pi }^{-}){\mu }^{+}{\mu }^{-}$ by the LHCb collaborations, as well as a new measurement of the $\Lambda \to p{\pi }^{-}$ decay asymmetry parameter by the BESIII collaboration, we study the impact of these results on searches for non-standard effects in exclusive $b\to s{\mu }^{+}{\mu }^{-}$ decays. To this end, we constrain the Wilson coefficients ${\mathcal{C}}_9$ and ${\mathcal{C}}_{10}$ of the numerically leading dimension-six operators in the weak effective Hamiltonian, in addition to the relevant nuisance parameters. In stark contrast to previous analyses of this decay mode, the changes in the updated experimental results lead us to find very good compatibility with both the Standard Model and with the $b\to s{\mu }^{+}{\mu }^{-}$ anomalies observed in rare $B$-meson decays. We provide a detailed analysis of the impact of the partial angular distribution, the full angular distribution, and the ${\Lambda }_b\to \Lambda {\mu }^{+}{\mu }^{-}$ branching fraction on the Wilson coefficients. In this process, we are also able to constrain the size of the production polarization of the ${\Lambda }_b$ baryon at LHCb.

   hep-phhep-exPRD(2020)·51 citations
9. 09*

   Spectrum of nonstrange singly charmed baryons in the constituent quark model

   Keval Gandhi🇮🇳 · Zalak Shah🇮🇳 · Ajay Kumar Rai🇮🇳

   We study the masses of radial and orbital excited states of nonstrange singly charmed baryons in the framework of hypercentral Constituent Quark Model (hCQM). To obtain the mass spectra, the Coulomb plus screened potential is employed with the first order correction, which gives a relativistic effect of order $\mathcal{O}$$(1/m)$. The spin-spin, spin-orbit and tensor interactions are included (perturbatively as a spin dependent potential) in order to generate the splitting in mass spectra. We compare our computed mass spectra of nonstrange singly charmed baryons with the other theoretical predictions as well as with the experimental observations. We construct the Regge trajectories of these baryons in the $(J,M^2)$ plane. Further, we analyze the strong one pion decay rates for $S$, $P$ and the $D$-wave transitions in the framework of Heavy Hadron Chiral Perturbation Theory (HHChPT). Moreover, the electromagnetic properties like magnetic moments, transition magnetic moments and the radiative decay widths are determined for the ground state of these baryons in the constituent quark model.

   hep-phInt.J.Theor.Phys.(2020)·30 citations
10. 10*

    Type-I Seesaw with eV-Scale Neutrinos

    G. C. Branco🇵🇹 · J. T. Penedo🇵🇹 · Pedro M. F. Pereira🇵🇹 · M. N. Rebelo🇵🇹 · J. I. Silva-Marcos🇵🇹

    We consider seesaw type-I models including at least one (mostly-)sterile neutrino with mass at the eV scale. Three distinct situations are found, where the presence of light extra neutrinos is naturally justified by an approximately conserved lepton number symmetry. To analyse these scenarios consistently, it is crucial to employ an exact parametrisation of the full mixing matrix. We provide additional exact results, including generalised versions of the seesaw relation and of the Casas-Ibarra parametrisation, valid for every scale of seesaw. We find that the existence of a light sterile neutrino imposes an upper bound on the lightest neutrino mass. We further assess the impact of light sterile states on short- and long-baseline neutrino oscillation experiments, emphasise future detection prospects, and address CP Violation in this framework via the analysis of CP asymmetries and construction of weak basis invariants. The proposed models can accommodate enough active-sterile mixing to play a role in the explanation of short-baseline anomalies.

    hep-phJHEP(2020)·29 citations
11. 11*

    Trimuon production at the LHC

    Mario W. Barela🇧🇷 · V. Pleitez🇧🇷

    No process without a standard model (SM) background has been observed so far. As a tool in the study of a class of models containing doubly charged vector bileptons, we propose one such process that, violating lepton flavor number conservation, has no contribution from the SM: $pp\to {\mu }^{+}{\mu }^{+}{\mu }^{-}{e}^{-}$. By carefully isolating the parameters to keep them free, we are able to acquire a notion of how a possible PMNS-like matrix present in the relevant charged current parametrization could affect the observables. We find that an interesting section of the space of parameters can be explored at the current LHC in the specified conditions.

    hep-phhep-exPRD(2020)·9 citations
12. 12*

    Heavy-light mesons beyond ladder approximation

    Pianpian Qin🇨🇳 · Si-xue Qin🇨🇳 · Yu-xin Liu🇨🇳

    The heavy-light mesons are studied within the framework of Dyson-Schwinger equations of QCD. Inspired by the axial-vector Ward-Takahashi identity resulting from the chiral symmetry, we propose a truncation scheme beyond the ladder approximation without introducing any additional parameter. For the pseudoscalar and vector heavy-light mesons, the obtained mass spectrum has the level of relative errors at $5\%$ compared with experimental data and lattice-QCD results. For the leptonic decay constants, our results are comparable with those from experiments and/or lattice QCD. For some channels, the discrepancies are sizable but significantly smaller than those using the equal spacing rule. The truncation scheme proposed in this work is simple and could be improved and applied to study other open flavor hadrons including both mesons and baryons.

    hep-phPRD(2020)·23 citations
13. 13*

    Photon pair production in gluon fusion: Top quark effects around threshold

    Long Chen🇩🇪 · Gudrun Heinrich🇩🇪 · Stephan Jahn🇩🇪 · Stephen P. Jones🇨🇭 · Matthias Kerner🇨🇭 · Johannes Schlenk🇨🇭 · Hiroshi Yokoya🇰🇷

    We present a calculation of the NLO QCD corrections to the loop-induced production of a photon pair through gluon fusion, including massive top quarks at two loops. The two-loop virtual amplitudes are computed via projecting onto a set of Lorentz structures related to linear polarisation states of external gauge bosons. All two-loop master integrals dependent on the top quark mass are evaluated numerically. Matching the fixed order NLO result to a calculation with threshold resummation, we obtain an accurate description of the diphoton invariant mass spectrum around the threshold of top quark pair production. We analyse how the distribution of the diphoton invariant mass is affected by the top quark loop-induced corrections, especially around the top quark pair production threshold.

    hep-phhep-exPoS(2019)·0 citations
14. 14*

    Multipole Moments of Heavy Vector and Axial-Vector Mesons in QCD

    T.M. Aliev🇹🇷 · S. Bilmis🇹🇷 · M. Savci🇹🇷

    The magnetic and quadrupole moments of the vector and axial-vector mesons containing heavy quark are estimated within the light cone sum rules method. Our predictions on magnetic moments for the vector mesons are compared with the results obtained by other approaches.

    hep-phPRD(2020)·9 citations
15. 15*

    Two-loop non-planar master integrals for top-pair production in the quark-annihilation channel

    Matteo Becchetti🇧🇪 · Roberto Bonciani🇮🇹 · Valerio Casconi🇮🇹 · Andrea Ferroglia🇺🇸 · Simone Lavacca🇮🇹 · Andreas von Manteuffel🇺🇸

    We present the analytic computation of the master integrals associated to certain two-loop non-planar topologies, which are needed to complete the evaluation of the last two color coefficients for the top-pair production in the quark-annihilation channel, which are not yet known analytically. The master integrals have been computed exploiting the differential equations method in canonical form. The solution is given as a series expansion in the dimensional regularization parameter through to weight four, the expansion coefficients are given in terms of multiple polylogarithms.

    hep-ph1 citation
16. 16*

    Lepton Flavour Symmetries

    Ferruccio Feruglio🇮🇹 · Andrea Romanino🇮🇹

    We provide a general classification of flavour symmetries according to their interplay with the proper Poincare' and gauge groups and to their linear or nonlinear action in field space. We focus on the lepton sector and we review the different types of symmetries describing neutrino masses and the lepton mixing matrix. For each type of symmetry we present several illustrative examples and we discuss specific strengths and limitations.

    hep-phRMP(2021)·272 citations
17. 17*

    Correlating uncertainties in global analyses within SMEFT matters

    Stefan Bißmann🇩🇪 · Johannes Erdmann🇩🇪 · Cornelius Grunwald🇩🇪 · Gudrun Hiller🇩🇪 · Kevin Kröninger🇩🇪

    We investigate the impact of correlations between (theoretical and experimental) uncertainties on multi-experiment, multi-observable analyses within the Standard Model Effective Field Theory (SMEFT). To do so, we perform a model-independent analysis of $t$-channel single top-quark production and top-quark decay data from ATLAS, CMS, CDF and D0. We show quantitatively how the fit changes when different experimental or theoretical correlations are assumed. Scaling down statistical uncertainties according to the luminosities of future colliders with $300{\mathrm{fb}}^{-1}$ and higher, we find that this effect becomes a matter of life and death: assuming no correlations returns a fit in agreement with the Standard Model while a 'best guess'-ansatz taking into account correlations would observe new physics. At the same time, modelling the impact of higher order SMEFT-corrections the latter turn out to be a subleading source of uncertainty only.

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

    Gravitational Waves from Supercool Axions

    Luigi Delle Rose🇮🇹 · Giuliano Panico🇮🇹 · Michele Redi🇮🇹 · Andrea Tesi🇮🇹

    We study the dynamics of the Peccei-Quinn (PQ) phase transition for the QCD axion. In weakly coupled models the transition is typically second order except in the region of parameters where the PQ symmetry is broken through the Coleman-Weinberg mechanism. In strongly coupled realizations the transition is often first order. We show examples where the phase transition leads to strong supercooling lowering the nucleation temperature and enhancing the stochastic gravitational wave signals. The models predict a frequency peak in the range 100-1000 Hz with an amplitude that is already within the sensitivity of LIGO and can be thoroughly tested with future gravitational wave interferometers.

    hep-phastro-ph.COhep-thJHEP(2020)·130 citations
19. 19*

    Lepton-Nucleus Cross Section Measurements for DUNE with the LDMX Detector

    Artur M. Ankowski🇺🇸 · Alexander Friedland🇺🇸 · Shirley Weishi Li🇺🇸 · Omar Moreno🇺🇸 · Philip Schuster🇺🇸 · Natalia Toro🇺🇸 · Nhan Tran🇺🇸

    We point out that the LDMX (Light Dark Matter eXperiment) detector design, conceived to search for sub-GeV dark matter, will also have very advantageous characteristics to pursue electron-nucleus scattering measurements of direct relevance to the neutrino program at DUNE and elsewhere. These characteristics include a 4-GeV electron beam, a precision tracker, electromagnetic and hadronic calorimeters with near 2$\pi$ azimuthal acceptance from the forward beam axis out to $\sim$40${}^{\circ }$ angle, and low reconstruction energy threshold. LDMX thus could provide (semi)exclusive cross section measurements, with detailed information about final-state electrons, pions, protons, and neutrons. We compare the predictions of two widely used neutrino generators (GENIE, GiBUU) in the LDMX region of acceptance to illustrate the large modeling discrepancies in electron-nucleus interactions at DUNE-like kinematics. We argue that discriminating between these predictions is well within the capabilities of the LDMX detector.

    hep-phhep-exnucl-exnucl-thPRD(2020)·31 citations
20. 20*

    A detailed study of the ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$ decays in the Standard Model

    Srimoy Bhattacharya🇮🇳 · Soumitra Nandi🇮🇳 · Sunando Kumar Patra🇮🇳 · Ria Sain🇮🇳

    Based on the standard model (SM) of particle physics, we study the decays ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$ in light of the available inputs from lattice and the data from LHCb. We fit the form-factors of this decay mode using the available theory and experimental inputs after defining different fit scenarios and checking their consistencies. The theory inputs include the relations between the form-factors in heavy quark effective theory (HQET) and soft collinear effective theory (SCET) at the endpoints of di-lepton invariant mass squared $q^2$. Utilizing the fit results, we have predicted a few observables related to this mode. We have also predicted the observable $R_{\Lambda }=Br({\Lambda }_b\to \Lambda {\ell }_i^{+}{\ell }_i^{-})/Br({\Lambda }_b\to \Lambda {\ell }_j^{+}{\ell }_j^{-})$ where ${\ell }_i$ and ${\ell }_j$ are charged leptons of different generations ($i\ne j$). At the moment, we do not observe noticeable differences in the extracted values of the observables in fully data-driven and SM like fit scenarios.

    hep-phhep-exhep-latPRD(2020)·11 citations
21. 21*

    Herwig 7.2 Release Note

    Johannes Bellm🇸🇪 · Gavin Bewick🇬🇧 · Silvia Ferrario Ravasio🇬🇧 · Stefan Gieseke🇩🇪 · David Grellscheid🇳🇴 · Patrick Kirchgaesser🇩🇪 · Mohammad R. Masouminia🇬🇧 · Graeme Nail🇬🇧 · Andreas Papaefstathiou🇬🇧 · Simon Platzer🇦🇹 · Michael Rauch🇩🇪 · Christian Reuschle🇸🇪 and 4 other authors

    A new release of the Monte Carlo event generator Herwig (version 7.2) is now available. This version introduces a number of improvements, notably: improvements to the simulation of multiple-parton interactions, including diffractive processes; a new model for baryonic colour re-connection; spin correlations in both the dipole and angular-ordered parton showers; improvements to strangeness production; an improved choice of evolution variable in the angular-ordered parton shower; support for generic Lorentz structures in BSM models.

    hep-phEPJC(2020)·256 citations
22. 22*

    Multi-gluon correlations and evidence of saturation from dijet measurements at an Electron Ion Collider

    Heikki Mäntysaari🇫🇮 · Niklas Mueller🇺🇸 · Farid Salazar🇺🇸 · Björn Schenke🇺🇸

    We study inclusive and diffractive dijet production in electron-proton and electron-nucleus collisions within the Color Glass Condensate effective field theory. We compute dijet cross sections differentially in both mean dijet transverse momentum $\mathbf{P}$ and recoil momentum $\mathbf{\Delta }$, as well as the anisotropy in the relative angle between $\mathbf{P}$ and $\mathbf{\Delta }$. We use the nonlinear Gaussian approximation to compute multiparticle correlators for general small $x$ kinematics, employing running coupling Balitsky-Kovchegov evolution to determine the dipole amplitude at small $x$. Our results cover a much larger kinematic range than accessible in previous computations performed in the correlation limit approximation, where it is assumed that $|\mathbf{P}|\gg |\mathbf{\Delta }|$. We validate this approximation in its range of applicability and quantify its failure for $|\mathbf{P}|\lesssim |\mathbf{\Delta }|$. We also predict significant target-dependent deviations from the correlation limit approximation for $|\mathbf{P}|>|\mathbf{\Delta }|$ and $|\mathbf{P}|\lesssim Q_s$, which offers a straightforward test of gluon saturation and access to multi-gluon distributions at a future electron ion collider.

    ↳ nucl-thhep-phPRL(2020)·79 citations
23. 23*

    Multi-Messenger Connections among High-Energy Cosmic Particles

    Kohta Murase🇺🇸

    The origin of high-energy cosmic neutrinos is one of the biggest mysteries in astroparticle physics. The fact that diffuse intensities of high-energy neutrinos, ultrahigh-energy cosmic rays, and GeV-TeV gamma rays are all comparable suggests that these messengers are physically connected. The IceCube data above 100 TeV energies can be naturally explained by cosmic-ray reservoir models. In particular, starburst galaxies and galaxy clusters/groups serve as natural storage rooms of cosmic rays, and it has been theoretically predicted that these sources are promising sites of high-energy neutrinos and gamma rays that are produced via inelastic pp interactions. Indeed, the predictions made before the discovery of IceCube neutrinos are consistent with the current high-energy neutrino data measured in IceCube, and that they could give a grand-unified view of sub-PeV neutrinos, sub-TeV gamma rays, and ultrahigh-energy cosmic rays. These unified models have strong prediction powers, which can be tested by next-generation neutrino detectors such as IceCube-Gen2 as well as gamma-ray telescopes such as CTA. The recent observations have also shown that the 10-100 TeV diffuse neutrino flux is higher than that at PeV energies, which suggests that they come from a different class of neutrino sources. The detailed comparison with the diffuse isotropic gamma-ray background measured by Fermi has revealed that these medium-energy neutrinos are likely to come from hidden cosmic-ray accelerators, from which neutrinos can escape while GeV-TeV gamma rays are attenuated. The candidate source classes are choked gamma-ray burst jets and active galactic nuclei (AGN) cores. In particular, the AGN corona model predicts a unique connection between 10-100 TeV neutrinos and MeV gamma rays, which can be robustly tested with future MeV gamma-ray missions such as AMEGO.

    ↳ astro-ph.HEhep-phPoS(2020)·6 citations
24. 24*

    Issues with Search for Critical Point in QCD with Relativistic Heavy Ion Collisions

    Masayuki Asakawa🇯🇵 · Masakiyo Kitazawa🇯🇵 · Berndt Müller🇺🇸

    A systematic search for a critical point in the phase diagram of QCD matter is underway at the Relativistic Heavy Ion Collider (RHIC) and is planned at several future facilities. Its existence, if confirmed, and its location will greatly enhance our understanding of QCD. In this note we emphasize several important issues that are often not fully recognized in theoretical interpretations of experimental results relevant to the critical point search. We discuss ways in which our understanding on these issues can be improved.

    ↳ nucl-thhep-phnucl-exPRC(2020)·18 citations
25. 25*

    Jets as precision probes in electron-nucleus collisions at the Electron-Ion Collider

    Miguel Arratia🇺🇸 · Youqi Song🇺🇸 · Felix Ringer🇺🇸 · Barbara V. Jacak🇺🇸

    We discuss the prospects of using jets as precision probes in electron-nucleus collisions at the future Electron-Ion Collider. Jets produced in deep-inelastic scattering can be calibrated by a measurement of the scattered electron. Such electron-jet "tag and probe" measurements call for an approach that is orthogonal to most HERA jet measurements as well as previous studies of jets at the future EIC. We present observables such as the electron-jet momentum balance, azimuthal correlations and jet substructure, which can provide constraints on the parton transport coefficient in nuclei. We compare simulations and analytical calculations and provide estimates of the expected medium effects. Implications for detector design at the future EIC are discussed.

    ↳ nucl-exhep-exhep-phnucl-thPRC(2020)·66 citations
26. 26*

    Composite topological objects in topological superfluids

    G.E. Volovik🇫🇮

    Superfluid phases of ${}^3$He discovered in 1972 opened the new area of the application of topological methods to condensed matter systems. Due to the multi-component order parameter which characterizes the broken $SO(3)\times SO(3)\times U(1)$ symmetry in these phases, there are many inhomogeneous objects -- textures and defects in the order parameter field -- which are protected by topology and are characterized by topological quantum numbers. Among them there are quantized vortices, skyrmions and merons, solitons and vortex sheets, monopoles and boojums, Alice strings, Kibble-Lazarides-Shafi walls terminated by Alice strings, spin vortices with soliton tails, etc. Most of them have been experimentally identified and investigated using nuclear magnetic resonance (NMR) techniquie, and in particular the phase coherent spin precession discovered in 1984 in ${}^3$He-B by Borovik-Romanov, Bunkov, Dmitriev and Mukharskiy in collaboration with Fomin.

    ↳ cond-mat.othergr-qchep-phJ.Exp.Theor.Phys.(2020)·13 citations
27. 27*

    Landau-Khalatnikov-Fradkin transformation of the fermion propagator in massless reduced QED

    A. James🇫🇷 · A. V. Kotikov🇷🇺 · S. Teber🇫🇷

    We study the gauge-covariance of the massless fermion propagator in reduced Quantum Electrodynamics (QED). Starting from its value in some gauge, we evaluate an all order expression for it in another gauge by means of the Landau-Khalatnikov-Fradkin transformation. We find that the weak coupling expansions thus derived are in perfect agreement with the exact calculations. We also prove that the fermion anomalous dimension of reduced QED is gauge invariant to all orders of perturbation theory except for the first one.

    ↳ hep-thcond-mat.mes-hallhep-phPRD(2020)·16 citations
28. 28*

    Future Physics Programme of BESIII

    M. Ablikim · M. N. Achasov · P. Adlarson · S. Ahmed · M. Albrecht · M. Alekseev · A. Amoroso · F. F. An · Q. An · Y. Bai · O. Bakina · R. Baldini Ferroli and 476 other authors

    There has recently been a dramatic renewal of interest in the subjects of hadron spectroscopy and charm physics. This renaissance has been driven in part by the discovery of a plethora of charmonium-like $XYZ$ states at BESIII and $B$ factories, and the observation of an intriguing proton-antiproton threshold enhancement and the possibly related $X(1835)$ meson state at BESIII, as well as the threshold measurements of charm mesons and charm baryons. We present a detailed survey of the important topics in tau-charm physics and hadron physics that can be further explored at BESIII over the remaining lifetime of BEPCII operation. This survey will help in the optimization of the data-taking plan over the coming years, and provides physics motivation for the possible upgrade of BEPCII to higher luminosity.

    ↳ hep-exhep-phCPC(2020)·818 citations
29. 29*

    Measurement of the branching fraction for the decay $K_S\to \pi \mu \nu$ with the KLOE detector

    D. Babusci🇮🇹 · M. Berlowski🇵🇱 · C. Bloise🇮🇹 · F. Bossi🇮🇹 · P. Branchini🇮🇹 · A. Budano🇮🇹 · B. Cao🇸🇪 · F. Ceradini🇮🇹 · P. Ciambrone🇮🇹 · F. Curciarello🇮🇹 · E. Czerwisnski · G. D'Agostini🇮🇹 and 44 other authors

    Based on a sample of 300 million $K_S$ mesons produced in $\varphi \to K_L{K}_S$ decays recorded by the KLOE experiment at the DA$\Phi$NE $e^{+}{e}^{-}$ collider we have measured the branching fraction for the decay $K_S\to \pi \mu \nu$. The $K_S$ mesons are identified by the interaction of $K_L$ mesons in the detector. The $K_S\to \pi \mu \nu$ decays are selected by a boosted decision tree built with kinematic variables and by a time-of-flight measurement. Signal efficiencies are evaluated with data control samples of $K_L\to \pi \mu \nu$ decays. A fit to the reconstructed muon mass distribution finds $7223\pm 180$ signal events. Normalising to the $K_S\to {\pi }^{+}{\pi }^{-}$ decay events the result for the branching fraction is $\mathcal{B}(K_S\to \pi \mu \nu )=(4.56\pm 0.11_{\mathrm{stat}}\pm 0.17_{\mathrm{syst}})\times 10^{-4}$.

    ↳ hep-exhep-phPLB(2020)·22 citations
30. 30*

    Non-perturbative renormalization by decoupling

    Mattia Dalla Brida🇮🇹 · Roman Höllwieser🇩🇪 · Francesco Knechtli🇩🇪 · Tomasz Korzec🇩🇪 · Alberto Ramos🇮🇪 · Rainer Sommer🇩🇪

    We propose a new strategy for the determination of the QCD coupling. It relies on a coupling computed in QCD with $N_{\mathrm{f}}\ge 3$ degenerate heavy quarks at a low energy scale ${\mu }_{\mathrm{dec}}$, together with a non-perturbative determination of the ratio $\Lambda /{\mu }_{\mathrm{dec}}$ in the pure gauge theory. We explore this idea using a finite volume renormalization scheme for the case of $N_{\mathrm{f}}=3$ QCD, demonstrating that a precise value of the strong coupling ${\alpha }_s$ can be obtained. The idea is quite general and can be applied to solve other renormalization problems, using finite or infinite volume intermediate renormalization schemes.

    ↳ hep-lathep-phPLB(2020)·30 citations
31. 31*

    Safe Gauge-String Correspondence

    Soo-Jong Rey🇰🇷 · Francesco Sannino🇩🇰

    Safe theories are quantum field theories whose continuum limit is defined by a non-Gaussian ultraviolet fixed point when the ultraviolet cutoff is removed. They constitute an important set in the space of quantum field theories. Here we develop the `safe' gauge-string correspondence program according to which $d$-dimensional safe gauge theories, admitting the `t Hooft-Veneziano limit, are holographically dual to $(d+1)$-dimensional safe noncritical string theories on asymptotically anti-de Sitter space. We provide evidences for this correspondence on a class of safe templates that engage fermion and scalar matter fields into gauge, Yukawa and Higgs self-interactions. Safe theories can feature in the infrared both a weak coupling phase and a strong coupling phase on either side of the ultraviolet fixed point. They correspond respectively to dilaton and warp factors taking domain-wall or Liouville-wall profiles on asymptotically anti-de Sitter space. We argue that four-dimensional $\mathcal{N}=4$ super Yang-Mills theories and all known interacting (super)conformal field theories are nonperturbative limit situations of safe gauge theories. The weak coupling phase provides a solvable holographic renormalization group flow while the strong coupling infrared phase provides a runaway-free alternative to holographic QCD.

    ↳ hep-thhep-phNPB(2022)·3 citations
32. 32*

    On Critical Exponents for Self-Similar Collapse

    Riccardo Antonelli🇮🇹 · Ehsan Hatefi🇮🇹

    We explore systematically perturbations of self-similar solutions to the Einstein-axion-dilaton system, whose dynamics are invariant under spacetime dilations combined with internal $SL(2,R)$ transformations. The self-similar solutions capture the enticing behavior critical systems on the verge of gravitational collapse, in arbitrary spacetime dimensions. Our methods rest on a combination of analytical and numerical tools, apply to all three conjugacy classes of $SL(2,R)$ transformations and allow accurate estimates of the corresponding Choptuik exponents. It is well known that these exponents depend on the spacetime dimension and on the matter content. Our main result is that they also attain different values, even within a given conjugacy class, for the distinct types of critical solutions that we recently identified in the Einstein-axion-dilaton system.

    ↳ hep-thgr-qchep-phmath-ph+1JHEP(2020)·15 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.