Tue·May 7, 2019Tuesday·May 7, 2019

1. 01*

   Resummation of Boson-Jet Correlation at Hadron Colliders

   Yang-Ting Chien🇺🇸 · Ding Yu Shao🇨🇭 · Bin Wu🇨🇭

   We perform a precise calculation of the transverse momentum (${\vec{q}}_T$) distribution of the boson+jet system in boson production events. The boson can be either a photon, $W$, $Z$ or Higgs boson with mass $m_V$, and ${\vec{q}}_T$ is the sum of the transverse momenta of the boson and the leading jet with magnitude $q_T=|{\vec{q}}_T|$. Using renormalization group techniques and soft-collinear effective theory, we resum logarithms $\log (Q/q_T)$ and $\log R$ at next-to-leading logarithmic accuracy including the non-global logarithms, where $Q$ and $R$ are respectively the hard scattering energy and the radius of the jet. Specifically, we investigate two scenarios of $p_T^J\lesssim m_V$ or $p_T^J\gtrsim m_V$ in $Z$+jet events, and we examine the $q_T$ distributions with different jet radii and study the effect of non-global logarithms. In the end we compare our theoretical calculations with Monte Carlo simulations and data from the LHC.

   hep-phhep-exnucl-exJHEP(2019)·59 citations
2. 02*

   Compact Perturbative Expressions for Oscillations with Sterile Neutrinos in Matter

   Stephen J. Parke🇺🇸 · Xining Zhang🇺🇸

   We extend a simple and compact method for calculating the three flavor neutrino oscillation probabilities in uniform matter density to schemes with sterile neutrinos, with favorable features inherited. The only constraint of the extended method is that the scale of the matter potential is not significantly larger than the atmospheric $\Delta m^2$, which is satisfied by all the running and proposed accelerator oscillation experiments. Degeneracy of the zeroth order eigensystem around solar and atmospheric resonances are resolved. Corrections to the zeroth order results are restricted to no larger than the ratio of the solar to the atmospheric $\Delta m^2$. The zeroth order expressions are exact in vacuum because all the higher order corrections vanish when the matter potential is set zero. Also because all the corrections are continuous functions of matter potential, the zeroth order precision is much better than $\Delta m_{\odot }^2/\Delta m_{\text{atm}}^2$ for weak matter effect. Numerical tests are presented to verify the theoretical predictions of the exceptional features. Moreover, possible applications of the method in experiments to check the existence of sterile neutrinos are discussed.

   hep-phPRD(2020)·15 citations
3. 03*

   SU(2) Charges with Spherical Symmetry and Confining Boundary Conditions

   Dennis Sivers🇺🇸

   Applying the static Yang-Mills Maxwell equations to a simple system of SU(2) charges with spherical symmetry and confining boundary conditions provides for a demonstration of the likelihood that the confinement mechanism in non-Abelian gauge theories necessarily involves a topologically-charged domain wall consisting of a surface volume with CP-odd field strength density. The surface volume of a color-singlet system of SU(2) charges therefor describes the magnetic dual of a topological insulator. This essential topological structure in inextricably connected to the hadronic dynamics of the pion tornado. In analogy to the kink solution in the 1+1 dimensional Abelian Higgs model the classical solutions for the field equations in spherically symmetric SU(2) with this domain wall of topological charge can lead to a mass gap in the quantum system

   hep-phPoS(2019)·0 citations
4. 04*

   Scotogenic Cobimaximal Dirac Neutrino Mixing from $\Delta (27)$ and $U(1{)}_{\chi }$

   Ernest Ma (UC Riverside)🇺🇸

   In the context of $SU(3{)}_C\times SU(2{)}_L\times U(1{)}_Y\times U(1{)}_{\chi }$, where $U(1{)}_{\chi }$ comes from $SO(10)\to SU(5)\times U(1{)}_{\chi }$, supplemented by the non-Abelian discrete $\Delta (27)$ symmetry for three lepton families, Dirac neutrino masses and their mixing are radiatively generated through dark matter. The gauge $U(1{)}_{\chi }$ symmetry is broken spontaneously. The discrete $\Delta (27)$ symmetry is broken softly and spontaneously. Together, they result in two residual symmetries, a global $U(1{)}_L$ lepton number and a dark symmetry, which may be $Z_2$, $Z_3$, or $U(1{)}_D$ depending on what scalar breaks $U(1{)}_{\chi }$. Cobimaximal neutrino mixing, i.e. ${\theta }_{13}\ne 0$, ${\theta }_{23}=\pi /4$, and ${\delta }_{CP}=\pm \pi /2$, may also be obtained.

   hep-phEPJC(2019)·45 citations
5. 05*

   Probing the charm-Higgs Yukawa coupling via Higgs boson decay to $h_c$ plus a photon

   Song Mao🇨🇳 · Yang Guo-He🇨🇳 · Li Gang🇨🇳 · Zhang Yu🇨🇳 · Guo Jian-You🇨🇳

   In this paper, we investigate the decay of Higgs boson to $h_c$ plus a photon in the NRQCD theoretical framework. Comparing with the Higgs decay to $J/\psi$ plus a photon channel, this process has not indirect contribution, can be used to detect the Yukawa coupling of Higgs and charm quarks. The results show that the decay branch ratio of this process is about $10^{-8}$. If we takes into account the $10^{-3}$ efficiency in the $h_c$ detection, no events will be available even in the case of $30a{b}^{-1}$ luminosity at FCC-pp with 100 TeV center of mass energy. However, if the detection efficiency of $h_c$ is greatly improved in the future, this process will play an important role at linear $e^{+}{e}^{-}$ future colliders and at LHCb. Moreover, this process should be also play an important role when the anomalous charm Yukawa couplings are larger and direct sensitivity.

   hep-phJ.Phys.G(2019)·10 citations
6. 06*

   Effects of finite spatial extent on Schwinger pair production

   Mamutjan Ababekri🇨🇳 · Bai-Song Xie🇨🇳 · Jun Zhang🇨🇳

   Electron-positron pair production from vacuum in external electric fields with space and time dependencies is studied numerically using real time Dirac-Heisenberg-Wigner formalism. The influence of spatial focusing scale of the electric field on momentum distribution and the total yield of the particles is examined by considering standing wave mode of the electric field with different temporal configurations. With the decrease of spatial extent of the external field, signatures of the temporal field are weaken in the momentum spectrum. Moreover, in the extremely small spatial extent, novel features emerge due to the combined effects of both temporal and spatial variations. We also find that for dynamically assisted particle production, while the total particle yield drops significantly in small spatial extents, the assistance mechanism tends to increase in these highly inhomogeneous regimes, where the slow and fast pulses are affected differently by the overall spatial inhomogeneity.

   hep-phquant-phPRD(2019)·38 citations
7. 07*

   Electric dipole moment of the electron in the model with extra Higgs bosons

   Noriyuki Oshimo🇯🇵

   The Higgs sector which is extended from the standard model could generally become an origin of CP violation. In the model with two doublet and one triplet Higgs fields on SU(2) symmetry, we study the electric dipole moment (EDM) of the electron whose non-vanishing value has not yet been established experimentally. The Higgs potential is assumed to be consistent with supersymmetric theory, though supersymmetric particles are not taken into consideration explicitly. While the parameter values of the model are severely constrained by the properties of the observed Higgs boson, certain ranges lead to a magnitude for the electron EDM around the experimental upper bound. Signatures of the extra Higgs bosons in collision experiments are discussed briefly.

   hep-ph1 citation
8. 08*

   Phenomenology of $b\to c\tau \bar{\nu }$ decays in a scalar leptoquark model

   Han Yan🇨🇳 · Ya-Dong Yang🇨🇳 · Xing-Bo Yuan🇨🇳

   During the past few years, hints of Lepton Flavour Universality (LFU) violation have been observed in $b\to c\tau \bar{\nu }$ and $b\to s{\ell }^{+}{\ell }^{-}$ transitions. Recently, the $D^{\ast }$ and $\tau$ polarization fractions $P_L^{D^{\ast }}$ and $P_L^{\tau }$ in $B\to D^{\ast }\tau \bar{\nu }$ decay have also been measured by the Belle collaboration. Motivated by these intriguing results, we revisit the $R_{D^{(\ast )}}$ and $R_{K^{(\ast )}}$ anomalies in a scalar leptoquark (LQ) model, in which two scalar LQs, one being $SU(2{)}_L$ singlet and the other $SU(2{)}_L$ triplet, are introduced simultaneously. We consider five $b\to c\tau \bar{\nu }$ mediated decays, $B\to D^{(\ast )}\tau \bar{\nu }$, $B_c\to {\eta }_c\tau \bar{\nu }$, $B_c\to J/\psi \tau \bar{\nu }$, and ${\Lambda }_b\to {\Lambda }_c\tau \bar{\nu }$, and focus on the LQ effects on the $q^2$ distributions of the branching fractions, the LFU ratios, and the various angular observables in these decays. Under the combined constraints by the available data on $R_{D^{(\ast )}}$, $R_{J/\psi }$, $P_L^{\tau }(D^{\ast })$, and $P_L^{D^{\ast }}$, we perform scans for the LQ couplings and make predictions for a number of observables. It is found numerically that both the differential branching fractions and the LFU ratios are largely enhanced by the LQ effects, with the latter being expected to provide testable signatures at the SuperKEKB and High-Luminosity LHC experiments.

   hep-phCPC(2019)·40 citations
9. 09*

   Equation of states and charmonium suppression in Heavy ion collisions

   Indrani Nilima🇮🇳 · Vineet Kumar Agotiya🇮🇳

   The present article is the follow-up of our work Bottomonium suppression in quasi-particle model, where we have extended the study for charmonium states using quasi-particle model in terms of quasi-gluons and quasi quarks/antiquarks as a equation of state. By employing medium modification to a heavy quark potential thermodynamic observables {\em viz.} pressure, energy density, speed of sound etc. have been calculated which nicely fit with the lattice equation of state for gluon, massless and as well {\em massive} flavored plasma. For obtaining the thermodynamic observables we employed the debye mass in the quasi particle picture. We extended the quasi-particle model to calculate charmonium suppression in an expanding, dissipative strongly interacting QGP medium (SIQGP). We obtained the suppression pattern for charmonium states with respect to the number of participants at mid-rapidity and compared it with the experimental data (CMS JHEP) and (CMS PAS) at LHC energy (Pb+Pb collisions, $\sqrt{s_{NN}}$= $2.76$ TeV).

   hep-phnucl-thAdv.High Energy Phys.(2019)·2 citations
10. 10*

    Estimating the variation of neutron star observables by symmetric dense nuclear matter properties

    Péter Pósfay🇭🇺 · Gergely Gábor Barnaföldi🇭🇺 · Antal Jakovác🇭🇺

    Recent multi-channel astrophysics observations and the soon-to-be published new measured electromagnetic and gravitation data provide information on the inner structure of the compact stars. These macroscopic observations can significantly increase our knowledge on the neutron star enteriors, providing constraints on the microscopic physical properties. On the other hand, due to the masquarade problem, there are still uncertainties on the various nuclear-matter models and their parameters as well. Calculating the properties of the dense nuclear matter, effective field theories are the most widely-used tools. However the values of the microscopical parameters need to be set consistently to the nuclear and astrophysical measurements. In this work we investigate how uncertainties are induced by the variation of the microscopical parameters. We use a symmetric nuclear matter in an extended $\sigma$-$\omega$ model. We calculate the dense matter equation of state and give the mass-radius diagram. We present that the Landau mass and compressibility modulus of the nuclear matter have definite linear relation to the maximum mass of a Schwarzschild neutron star.

    hep-phastro-ph.HEnucl-thUniverse(2019)·7 citations
11. 11*

    Operator Relations for Gravitational Form Factors

    Kazuhiro Tanaka (Juntendo Univ.)🇯🇵

    The form factors for the hadron matrix element of the QCD energy-momentum tensor not only describe the coupling of the hadron with a graviton as the ``gravitational form factors'', but also serve as unique quantities for describing the shape inside the hadron reflecting dynamics of quarks and gluons, such as the internal shear forces acting on the quarks/gluons and their pressure distributions. We consider the gravitational form factors for a hadron, in particular, for a (pseudo)scalar hadron and for the nucleon. We derive and clarify the relations satisfied by the gravitational form factors as direct consequences of the symmetries and the equations of motion in QCD, and connections to the generalized parton distributions. Our results reveal that the gravitational form factors are related to the higher-twist quark-gluon correlation effects inside the hadrons and also to QCD trace anomaly.

    hep-phhep-exnucl-exnucl-thJPS Conf.Proc.(2019)·1 citation
12. 12*

    Unified Analyses of Multiplicity Distributions and Bose-Einstein Correlations at the LHC using Double-Stochastic Distributions

    Takuya Mizoguchi🇯🇵 · Minoru Biyajima🇯🇵

    We analyze data on multiplicity distributions (MD) at Large Hadron Collider (LHC) energies using a double-negative binomial distribution (D-NBD) and double-generalized Glauber-Lachs formula (D-GGL). Moreover, we investigate the Bose-Einstein correlation (BEC) formulas based on these distributions and analyze the BEC data using the parameters obtained by analysis of MDs. From these analyses it can be inferred that the D-GGL formula performs as effectively as the D-NBD. Moreover, our results show that the parameters estimated in MD are related to those contained in the BEC formula.

    hep-phnucl-thJPS Conf.Proc.(2019)·5 citations
13. 13*

    Unbiased determination of DVCS Compton Form Factors

    H. Moutarde🇫🇷 · P. Sznajder🇵🇱 · J. Wagner🇵🇱

    The extraction of Compton Form Factors (CFFs) in a global analysis of almost all Deeply Virtual Compton Scattering (DVCS) proton data is presented. The extracted quantities are DVCS sub-amplitudes and the most basic observables which are unambiguously accessible from this process. The parameterizations of CFFs are constructed utilizing the artificial neural network technique allowing for an important reduction of model dependency. The analysis consists of such elements as feasibility studies, training of neural networks with the genetic algorithm and a careful regularization to avoid over-fitting. The propagation of experimental uncertainties to extracted quantities is done with the replica method. The resulting parameterizations of CFFs are used to determine the subtraction constant through dispersion relations. The analysis is done within the PARTONS framework.

    hep-phEPJC(2019)·88 citations
14. 14*

    Probing an additional bottom Yukawa coupling via $bg\to bA\to bZH$ signature

    Tanmoy Modak🇹🇼

    The recent discovery of the bottom quark Yukawa coupling ($hbb$) of the 125 GeV scalar motivates one to search for extra bottom Yukawa coupling that may exist in the nature. The two Higgs doublet model without a discrete $Z_2$ symmetry allows the possibility of additional bottom Yukawa coupling ${\rho }_{bb}$. We show that ${\rho }_{bb}$ can be searched directly at the LHC via $bg\to bA\to bZH$ and $gg\to b\bar{b}A\to b\bar{b}ZH$ processes, where $A$ and $H$ are the CP-odd and CP-even scalars respectively. We find that the $bg\to bA\to bZH$ process could be discovered with $\sim 300$ fb${}^{-1}$ integrated luminosity if $m_A\sim 300$ GeV, while the latter process may emerge in the high luminosity LHC (HL-LHC) data. A discovery might touch upon the parameter space required for the electroweak baryogenesis.

    hep-phhep-exPRD(2019)·7 citations
15. 15*

    Large scale analytic calculations in quantum field theories

    Johannes Blümlein🇩🇪

    We present a survey on the mathematical structure of zero- and single scale quantities and the associated calculation methods and function spaces in higher order perturbative calculations in relativistic renormalizable quantum field theories.

    hep-phhep-thmath-phmath.MP14 citations
16. 16*

    Hypercharged Naturalness

    Javi Serra🇩🇪 · Stefan Stelzl🇩🇪 · Riccardo Torre🇨🇭 · Andreas Weiler🇩🇪

    We present an exceptional twin-Higgs model with the minimal symmetry structure for an exact implementation of twin parity along with custodial symmetry. Twin particles are mirrors of the Standard Model yet they carry hypercharge, while the photon is identified with its twin. We thoroughly explore the phenomenological signatures of hypercharged naturalness: long-lived charged particles, a colorless twin top with electric charge $2/3$ that once pair-produced, bounds via twin-color interactions and can annihilate to dileptons or a Higgs plus a photon or a $Z$, and glueballs produced from Higgs decays and twin-quarkonium annihilation that either decay displaced, or are stable on collider scales and eventually decay to diphotons. Prospects for detection of these signatures are also discussed.

    hep-phhep-exJHEP(2019)·30 citations
17. 17*

    Fitting the b-quark PDF as a massive-b scheme: Higgs production in bottom fusion

    Stefano Forte🇮🇹 · Tommaso Giani🇬🇧 · Davide Napoletano🇫🇷

    We show that a simple and accurate approach to the computation of hadron collider processes involving initial-state $b$ quarks can be obtained by introducing an independently parametrized b PDF. We use the so-called FONLL method for the matching of a scheme in which the b quark is treated as a massless parton to that in which it is treated as a massive state, and extend it to the case in which the b quark PDF is not necessarily determined by perturbative matching conditions. This generalizes to hadronic collisions analogous results previously obtained for deep-inelastic scattering. The results corresponds to a `massive b' scheme, in which b mass effects are retained, yet the b quark is endowed with a PDF. We specifically study Higgs production in bottom fusion, and show that our approach overcomes difficulties related to the fact that in a standard massive four-flavor scheme b-quark induced processes only start at high perturbative orders.

    hep-phhep-exEPJC(2019)·21 citations
18. 18*

    Probing Axions with Event Horizon Telescope Polarimetric Measurements

    Yifan Chen🇫🇷 · Jing Shu🇨🇳 · Xiao Xue🇨🇳 · Qiang Yuan🇨🇳 · Yue Zhao🇺🇸

    With high spatial resolution, polarimetric imaging of a supermassive black hole, like M87${}^{\star }$ or Sgr A${}^{\star }$, by the Event Horizon Telescope can be used to probe the existence of ultralight bosonic particles, such as axions. Such particles can accumulate around a rotating black hole through the superradiance mechanism, forming an axion cloud. When linearly polarized photons are emitted from an accretion disk near the horizon, their position angles oscillate due to the birefringent effect when traveling through the axion background. In particular, the observations of supermassive black holes M87${}^{\star }$ (Sgr A${}^{\star }$) can probe the dimensionless axion-photon coupling $c=2\pi g_{a\gamma }{f}_a$ for axions with mass around $O(10^{-20})$~eV ($O(10^{-17}$)~eV) and decay constant $f_a<O(10^{16})$ GeV, which is complimentary to other axion measurements.

    hep-phastro-ph.COgr-qcPRL(2020)·153 citations
19. 19*

    Sensitivity measuring expected on the electromagnetic anomalous couplings in the $t\bar{t}\gamma$ vertex at the FCC-he

    M. Köksal🇹🇷 · A. A. Billur🇹🇷 · A. Gutiérrez-Rodríguez🇲🇽 · M. A. Hernández-Ruíz🇲🇽

    In this paper, we consider the electroweak production cross-section of a single anti-top-quark, a neutrino and a photon via charged current through the $e^{-}p\to e^{-}\bar{b}\to \bar{t}{\nu }_e\gamma \to \bar{t}(\to W^{-}\to (q{q}^{\prime },l^{-}{\bar{\nu }}_l)+b){\nu }_e\gamma$ signal. Further, we derived the sensitivity expected to the magnetic dipole moment $({\hat{a}}_V)$ and the electric dipole moment $({\hat{a}}_A)$ of the top-quark at the Future Circular Collider Hadron Electron (FCC-he). We present our study for $\sqrt{s}=7.07,10TeV$, $\mathcal{L}=50,100,300,500,1000f{b}^{-1}$, ${\delta }_{sys}=0,3,5\%$ and $P_{e^{-}}=0\%,80\%,-80\%$, respectively. We find that the sensitivity estimated on dipole moments of the top-quark is of the order of magnitude $\mathcal{O}(10^{-1})$ for both hadronic and leptonic decay modes of $W^{-}$: ${\hat{a}}_V=[-0.2308,0.2204]$, $|{\hat{a}}_A|=0.2259$ at $95\%$ C.L. in the hadronic channel with unpolarized electron beam $P_{e^{-}}=0\%$. Our results with polarized electron beam for $P_{e^{-}}=80\%$ and $P_{e^{-}}=-80\%$ are ${\hat{a}}_V=[-0.3428,0.3321]$, $|{\hat{a}}_A|=0.3371$ and ${\hat{a}}_V=[-0.2041,0.1858]$, $|{\hat{a}}_A|=0.1939$ at $95\%$ C.L. in the hadronic channel. The corresponding results for the leptonic channel with $P_{e^{-}}=0\%,80\%-80\%$ are ${\hat{a}}_V=[-0.3067,0.2963]$, $|{\hat{a}}_A|=0.3019$, ${\hat{a}}_V=[-0.4563,0.4456]$, $|{\hat{a}}_A|=0.4505$ and ${\hat{a}}_V=[-0.2695,0.2512]$, $|{\hat{a}}_A|=0.2592$, respectively. The results for ${\hat{a}}_V$ and ${\hat{a}}_A$ in the leptonic channel are weaker by a factor of 0.75 than those corresponding to the hadronic channel. Given these prospective sensitivities we highlight that the FCC-he is potential top-quark factory that is particularly well suited to sensitivity study on its dipole moments and with cleaner environments.

    hep-phInt.J.Mod.Phys.A(2020)·11 citations
20. 20*

    Baryons in a soft-wall AdS-Schwarzschild approach at low temperature

    Thomas Gutsche🇩🇪 · Valery E. Lyubovitskij🇩🇪 · Ivan Schmidt🇨🇱 · Andrey Yu. Trifonov🇷🇺

    Recently we derived a soft-wall AdS-Schwarzschild approach at small temperatures for the description of hadrons with integer spin and adjustable number of constituents (mesons, tetraquarks, dibaryons, etc.). In the present paper we extend our formalism to states with half-integer spin (baryons, pentaquarks, etc.), presenting analytical results for the temperature dependence of their masses and form factors.

    hep-phPRD(2019)·22 citations
21. 21*

    Energy correlations in the end-point region

    G. P. Korchemsky🇫🇷

    The energy-energy correlation (EEC) measures the angular distribution of the energy that flows through two calorimeters separated by some relative angle in the final state created by a source. We study this observable in the limit of small and large angles when it describes the correlation between particles belonging, respectively, to the same jet and to two almost back-to-back jets. We present a new approach to resumming large logarithmically enhanced corrections in both limits that exploits the relation between the energy correlations and four-point correlation functions of conserved currents. At large angle, we derive the EEC from the behaviour of the correlation function in the limit when four operators are light-like separated in a sequential manner. At small angle, in a conformal theory, we obtain the EEC from resummation of the conformal partial wave expansion of the correlation function at short-distance separation between the calorimeters. In both cases, we obtain a concise representation of the EEC in terms of the conformal data of twist-two operators and verify it by comparing with the results of explicit calculation at next-to-next-to-leading order in maximally supersymmetric Yang-Mills theory. As a byproduct of our analysis, we predict the maximal weight part of the analogous QCD expression in the back-to-back limit.

    ↳ hep-thhep-phJHEP(2020)·103 citations
22. 22*

    PBH remnants as dark matter produced in thermal, matter and runaway-quintessence post-inflationary scenarios

    Ioannis Dalianis🇬🇷 · George Tringas🇬🇷

    We investigate the cosmology of mini Primordial Black Holes (PBHs) produced by large density perturbations. The mini PBHs evaporate promptly in the early universe and we assume that a stable remnant is left behind. The PBHs remnants can constitute the entire dark matter of the universe for a wide range of remnant masses. We build inflationary models, in the framework of $\alpha$-attractors utilizing exponential functions, in which the PBHs are produced during matter, radiation and kination domination eras. The advantage of these inflationary models is that the spectral index takes values favorable by the Planck 2018 data. The PBH production from runaway inflaton models has the unique and very attractive feature to automatically reheat the universe. In these models the PBHs are produced during the kination stage and their prompt evaporation efficiently produces the required entropy. Such runaway models are remarkably economic having interesting implications for the early universe cosmology, possibly giving rise to a wCDM late time cosmology as well.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2019)·68 citations
23. 23*

    Aharonov-Bohm defects

    Chandrasekhar Chatterjee🇯🇵 · Muneto Nitta🇯🇵

    We discuss what happens when a field receiving an Aharonov-Bohm (AB) phase develops a vacuum expectation value (VEV), with an example of an Alice string in a $U(1)\times SU(2)$ gauge theory coupled with complex triplet scalar fields. We introduce scalar fields belonging to the doublet representation of $SU(2)$, charged or chargeless under the $U(1)$ gauge symmetry, that receives an AB phase around the Alice string. When the doublet develops a VEV, the Alice string turns to a global string in the absence of the interaction depending on the relative phase between the doublet and triplet, while, in the presence of such an interaction, the Alice string is confined by a soliton or domain wall and therefore the spontaneous breaking of a spatial rotation around the string is accompanied. We call such an object induced by an AB phase as an ``AB defect'', and argue that such a phenomenon is ubiquitously appearing in various systems.

    ↳ hep-thhep-phPRD(2020)·8 citations
24. 24*

    The flavor dependence of $m_{\varrho }/f_{\pi }$

    Daniel Nogradi · Lorinc Szikszai

    We calculate the $m_{\varrho }/f_{\pi }$ ratio in the chiral and continuum limit for $SU(3)$ gauge theory coupled to $N_f=2,3,4,5,6$ fermions in the fundamental representation. Keeping all systematic effects under full control we find no statistically significant $N_f$-dependence; $m_{\varrho }/f_{\pi }=7.95(15)$. Assuming the KSRF-relations we conclude that 3 other low energy quantities related to the vector meson are also $N_f$-independent within errors including the $\varrho \pi \pi$ coupling $g_{\varrho \pi \pi }$. If the model is thought of as a strong dynamics inspired composite Higgs model our results indicate that the experimentally most easily accessible new composite particle, the vector meson, and its properties may be robust and independent of the fermion content of the model as long as the gauge group is $SU(3)$, provided $N_f$-independence extends all the way to the conformal window.

    ↳ hep-lathep-phJHEP(2019)·19 citations
25. 25*

    Constraints on the Dark Matter Interpretation $n\to \chi +e^{+}{e}^{-}$ of the Neutron Decay Anomaly with the PERKEO II experiment

    M. Klopf🇦🇹 · E. Jericha🇦🇹 · B. Märkisch🇩🇪 · H. Saul🇩🇪 · T. Soldner🇫🇷 · H. Abele🇦🇹

    Discrepancies from in-beam and in-bottle type experiments measuring the neutron lifetime are on the 4$\sigma$ standard deviation level. In a recent publication Fornal and Grinstein proposed that the puzzle could be solved if the neutron would decay on the one percent level via a dark decay mode, one possible branch being $n\to \chi +e^{+}{e}^{-}$. With data from the \perkeoII experiment we set limits on the branching fraction and exclude a one percent contribution for $95\%$ of the allowed mass range for the dark matter particle.

    ↳ hep-exhep-phnucl-exPRL(2019)·35 citations
26. 26*

    Remnants of Galactic subhalos and their impact on indirect dark matter searches

    Martin Stref🇫🇷 · Thomas Lacroix🇪🇸 · Julien Lavalle🇫🇷

    Dark matter subhalos, predicted in large numbers in the cold dark matter scenario, should have an impact on particle dark matter searches. Recent results show that tidal disruption of these objects in computer simulations is over-efficient due to numerical artifacts and resolution effects. Accounting for these results, we re-estimate the subhalo abundance in the Milky Way using semi-analytical techniques. In particular, we show that the boost factor for gamma rays and cosmic-ray antiprotons is increased by roughly a factor of two.

    ↳ astro-ph.COastro-ph.GAhep-phGalaxies(2019)·25 citations
27. 27*

    Magnetized baryons and the QCD phase diagram: NJL model meets the lattice

    Gergely Endrődi🇩🇪 · Gergely Markó🇭🇺

    We determine the baryon spectrum of 1 + 1 + 1-flavor QCD in the presence of strong background magnetic fields using lattice simulations at physical quark masses for the first time. Our results show a splitting within multiplets according to the electric charge of the baryons and reveal, in particular, a reduction of the nucleon masses for strong magnetic fields. This first-principles input is used to define constituent quark masses and is employed to set the free parameters of the Polyakov loop-extended Nambu-Jona-Lasinio (PNJL) model in a magnetic field-dependent manner. The so constructed model is shown to exhibit inverse magnetic catalysis at high temperatures and a reduction of the transition temperature as the magnetic field grows - in line with non-perturbative lattice results. This is contrary to the naive variant of this model, which gives incorrect results for this fundamental phase diagram. Our findings demonstrate that the magnetic field dependence of the PNJL model can be reconciled with the lattice findings in a systematic way, employing solely zero-temperature first-principles input.

    ↳ hep-lathep-phnucl-thJHEP(2019)·70 citations
28. 28*

    Towards baryon-baryon scattering in manifestly Lorentz-invariant formulation of SU(3) baryon chiral perturbation theory

    V. Baru🇩🇪 · E. Epelbaum🇩🇪 · J. Gegelia🇩🇪 · X.-L. Ren🇩🇪

    We study baryon-baryon scattering by applying time-ordered perturbation theory to the manifestly Lorentz-invariant formulation of SU(3) baryon chiral perturbation theory. We derive the corresponding diagrammatic rules paying special attention to complications caused by momentum-dependent interactions and propagators of particles with non-zero spin. We define the effective potential as a sum of two-baryon irreducible contributions of time-ordered diagrams and derive a system of integral equations for the scattering amplitude, which provides a coupled-channel generalization of the Kadyshevsky equation. The obtained leading-order baryon-baryon potentials are perturbatively renormalizable, and the corresponding integral equations have unique solutions in all partial waves. We discuss the issue of additional finite subtractions required to improve the ultraviolet convergence of (finite) loop integrals on the example of nucleon-nucleon scattering in the ${}^3{P}_0$ partial wave. Assuming that corrections beyond leading order can be treated perturbatively, we obtain a fully renormalizable formalism which can be employed to study baryon-baryon scattering.

    ↳ nucl-thhep-phPLB(2019)·29 citations
29. 29*

    Renormalization Scheme Dependence, RG Flow and Borel Summability in ${\varphi }^4$ Theories in $d<4$

    Giacomo Sberveglieri🇮🇹 · Marco Serone🇮🇹 · Gabriele Spada🇫🇷

    Renormalization group (RG) and resummation techniques have been used in $N$-component ${\varphi }^4$ theories at fixed dimensions below four to determine the presence of non-trivial IR fixed points and to compute the associated critical properties. Since the coupling constant is relevant in $d<4$ dimensions, the RG is entirely governed by renormalization scheme-dependent terms. We show that the known proofs of the Borel summability of observables depend on the renormalization scheme and apply only in "minimal" ones, equivalent in $d=2$ to an operatorial normal ordering prescription, where the $\beta$-function is trivial to all orders in perturbation theory. The presence of a non-trivial fixed point can be unambiguously established by considering a physical observable, like the mass gap, with no need of RG techniques. Focusing on the $N=1$, $d=2$ ${\varphi }^4$ theory, we define a one-parameter family of renormalization schemes where Borel summability is guaranteed and study the accuracy on the determination of the critical exponent $\nu$ as the scheme is varied. While the critical coupling shows a significant sensitivity on the scheme, the accuracy in $\nu$ is essentially constant. As by-product of our analysis, we improve the determination of $\nu$ obtained with RG methods by computing three more orders in perturbation theory.

    ↳ hep-thcond-mat.stat-mechhep-phmath-ph+1PRD(2019)·17 citations
30. 30*

    Universal scaling of meson and baryon spectra in p-Pb collisions at 5.02 TeV

    N. Liu🇨🇳 · X.L. Du🇨🇳 · L.Y. Qiao🇨🇳 · G.R. Che🇨🇳 · W.C. Zhang🇨🇳

    We systematically investigate the scaling property of mesons (pions and kaons) and baryons (protons, $\mathrm{\Lambda }$, $\mathrm{\Xi }$ and $\mathrm{\Omega }$) transverse momentum ($p_{\mathrm{T}}$) spectra at different centrality classes (0-5$\%$, 5-10$\%$, 10-20$\%$, 20-40$\%$, 40-60$\%$, 60-80$\%$ and 80-100$\%$) in proton-lead collisions with center of mass energy per nucleon pair 5.02 TeV. In the low $p_{\mathrm{T}}$ region with $p_{\mathrm{T}}\le$ 3.9 (3.1, 2.5, 2.7, 2.4 and 2.8) GeV/c, a universal scaling independent of the centrality is observed in the pion (kaon, proton, $\mathrm{\Lambda }$, $\mathrm{\Xi }$ and $\mathrm{\Omega }$) spectra when a dilatation, $p_{\mathrm{T}}\to p_{\mathrm{T}}/K$, is applied. Here $K$ is a scaling parameter depending on the centrality class. We find that the rates at which ln$K$ changes with the logarithmic value of the average value of the number of participating nucleons, ln$⟨N_{\mathrm{part}}⟩$, are stronger for baryons than those for mesons. In the high $p_{\mathrm{T}}$ region, there is a deviation from the scaling. The more peripheral the collisions are, the more obvious the violation of the scaling is. In the framework of the colour string percolation (CSP) model, we show that mesons and baryons are generated from the decay of clusters formed by strings overlapping in the transverse plane with the same size dispersion but with different mean size. The mean size of clusters for baryons is smaller than that of mesons. For the same hadrons at different centrality classes, the mean size of clusters decreases with the increase of centrality. The fragmentation functions for cluster decay are different for different hadrons, while they are universal for the same hadrons at different centrality classes. The universal scaling of the meson and baryon spectra in the low $p_{\mathrm{T}}$ region can be quantitatively understood with the CSP model at the same time.

    ↳ nucl-thhep-phIJMPE(2019)·2 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.