Tue·Nov 5, 2019Tuesday·November 5, 2019

1. 01*

   Axion-photon-dark photon oscillation and its implication for 21 cm observation

   Kiwoon Choi🇰🇷 · Hyeonseok Seong🇰🇷 · Seokhoon Yun🇰🇷

   We examine the resonant conversion of axion-like particle (ALP) or dark photon to the electromagnetic photon in the early Universe, which takes place due to the ALP-photon-dark photon oscillations in background dark photon gauge fields. It is noted that the corresponding conversion probability can have an unusual spectral feature which allows strong conversion at low frequency domain, but has negligible conversion at high frequencies above certain critical frequency which is determined by the ALP coupling to dark photon and the strength of background dark photon gauge field. We apply this scheme to heat up the 21 cm photons without affecting the Cosmic Microwave Background, which can explain the tentative absorption signal of 21 cm photons detected recently by the EDGES experiment.

   hep-phastro-ph.COPRD(2020)·38 citations
2. 02*

   On Magnetic Forces and Work

   Jacob A. Barandes🇺🇸

   We address a long-standing debate over whether classical magnetic forces can do work, ultimately answering the question in the affirmative. In detail, we couple a classical particle with intrinsic spin and elementary dipole moments to the electromagnetic field, derive the appropriate generalization of the Lorentz force law, show that the particle's dipole moments must be collinear with its spin axis, and argue that the magnetic field does mechanical work on the particle's elementary magnetic dipole moment. As consistency checks, we calculate the overall system's energy-momentum and angular momentum, and show that their local conservation equations lead to the same force law and therefore the same conclusions about magnetic forces and work. We also compute the system's Belinfante-Rosenfeld energy-momentum tensor.

   hep-phhep-thphysics.class-phFound.Phys.(2021)·1 citation
3. 03*

   Effect of color reconnection and rope formation on resonance production in p$-$p collisions in Pythia 8

   Ankita Goswami🇩🇪 · Ranjit Nayak🇮🇳 · Basanta Kumar Nandi🇮🇳 · Sadhana Dash🇮🇳

   The resonance production in proton$-$proton collisions at $\sqrt{s}$ = 7 TeV and 13 TeV have been investigated using Pythia 8 event generator within the framework of microscopic processes like color reconnection and rope hadronization. Specifically, the observable effects of different modes of color reconnections on the ratio of yields of mesonic and baryonic resonances with respect to their stable counterpart have been explored as a function of event activity. A suppression in the ratio is observed as a function of number of multi-partonic interactions for mesonic resonances. The $\varphi /K$ and $\varphi /\pi$ ratios show an enhancement for high multiplicity events due to enhanced production of strange quarks via the microscopic process of rope hadronization in the partonic phase. The mechanism of the hadronization of color ropes together with the QCD-based color reconnection of partons predicted an enhancement in the ratio for baryonic resonances to non-resonance baryons having similar quark content. The yield ratios of resonances are found to be independent of the collision energy and strongly dependent on event activity.

   hep-phEPJC(2021)·8 citations
4. 04*

   Analysis of singularities and the four-dimensional representation of physical observables within the LTD formalism

   German F. R. Sborlini🇪🇸

   In the past years, we have been developing a novel technique, called Four-Dimensional Unsubtraction (FDU) which aims to obtain purely four-dimensional representations of the matrix elements contributing to physical observables. In this talk, we describe the application of the loop-tree duality (LTD) theorem to represent loop amplitudes in terms of tree-level like objects, focusing on the origin of possible singularities of scattering amplitudes. In particular, we analyze the regions responsible of infrared and threshold singularities. With this information, we aim to extend the FDU formalism to NNLO and beyond.

   hep-phhep-thPoS(2020)·0 citations
5. 05*

   Experimental Aspects of Jet Physics at a Future EIC

   B. S. Page🇺🇸 · Xiaoxuan Chu🇺🇸 · E. C. Aschenauer🇺🇸

   In this work, we present an overview of experimental considerations relevant to the utilization of jets at a future Electron-Ion Collider (EIC), a subject which has been largely overlooked up to this point. A comparison of jet-finding algorithms and resolution parameters is presented along with a detailed analysis of basic jet quantities, such as multiplicities and kinematic distributions. A characterization of the energy in the event not associated with a jet is also made. In addition, detector requirements and the effects of realistic detector resolutions are discussed. Finally, an example analysis is presented in which dijets are used to access the gluon helicity contribution to the spin of the proton.

   hep-phhep-exnucl-exPRD(2020)·38 citations
6. 06*

   Soft contribution to the damping rate of a hard photon in a weakly magnetized hot medium

   Ritesh Ghosh🇮🇳 · Bithika Karmakar🇮🇳 · Munshi G Mustafa🇮🇳

   We consider weakly magnetized hot QED plasma comprising electrons and positrons. There are three distinct dispersive (longitudinal and two transverse) modes of a photon in a thermo-magnetic medium. At lowest order in coupling constant, photon is damped in this medium via Compton scattering and pair creation process. We evaluate the damping rate of hard photon by calculating the imaginary part of the each transverse dispersive modes in a thermo-magnetic QED medium. We note that one of the fermions in the loop of one-loop photon self-energy is considered as soft and the other one is hard. Considering the resummed fermion propagator in a weakly magnetized medium for the soft fermion and the Schwinger propagator for hard fermion, we calculate the soft contribution to the damping rate of hard photon. In weak field approximation the thermal and thermo-magnetic contributions to damping rate get separated out for each transverse dispersive mode. The total damping rate for each dispersive mode in presence of magnetic field is found to be reduced than that of the thermal one. This formalism can easily be extended to QCD plasma.

   hep-phhep-latnucl-thPRD(2020)·17 citations
7. 07*

   $U(1{)}_{B-3L_{\alpha }}$ Extended Scotogenic Models and Single-zero Textures of Neutrino Mass Matrices

   Weijian Wang🇨🇳 · Zhi-Long Han🇨🇳

   In this paper, we propose a scotogenic model of neutrino masses with flavor-dependent $U(1{)}_{B-3L_{\alpha }}(\alpha =e,\mu ,\tau )$ gauge symmetry, in which neutrinos are generated at one-loop level and a fermion dark matter is naturally accommodated. In this model, three one-zero-texture structures of neutrino mass matrix, denoted as patterns A, B and C, are successfully realized by appropriate charge assignment for inert fermions and scalar fields. For each predicted textures, a detailed numerical analysis is carried out to find the allowed regions of neutrino mixing and masses. We find three scenarios (A for normal mass hierarchy, and B and C for inverted mass hierarchy) favored by the latest data of neutrino oscillation experiments and Planck 2018 limit on the sum of neutrino masses. Other phenomenologies such as lepton flavor violation, dark matter and collider signatures are also discussed.

   hep-phPRD(2020)·10 citations
8. 08*

   Charmed hadron production via equal-velocity quark combination in ultra-relativistic heavy ion collisions

   Rui-Qin Wang🇨🇳 · Jun Song🇨🇳 · Feng-Lan Shao🇨🇳 · Zuo-Tang Liang🇨🇳

   Recent data on the production of $D$ mesons and ${\Lambda }_c^{+}$ baryons in heavy ion collisions at the Relativistic Heavy Ion Collider and the Large Hadron Collider exhibit a number of striking characteristics such as enhanced yield ratios $D_s^{+}/D^0$, ${\Lambda }_c^{+}/D^0$ and their transverse momentum dependences. In this paper, we derive the momentum dependence of open charm mesons and singly charmed baryons produced in ultra-relativistic heavy ion collisions via the equal-velocity quark combination. We present analytic expressions and numerical results of yield ratios and compare them with the experimental data available. We make predictions for other charmed hadrons.

   hep-phhep-exnucl-thPRC(2020)·9 citations
9. 09*

   Discovery of Quark-Gluon-Plasma: Strangeness Diaries

   Johann Rafelski🇺🇸

   We look from a theoretical perspective at the new phase of matter, quark-gluon plasma (QGP), the new form of nuclear matter created at high temperature and pressure. Here I retrace the path to QGP discovery and its exploration in terms of strangeness production and strange particle signatures. We will see the theoretical arguments that have been advanced to create interest in this determining signature of QGP. We explore the procedure used by several experimental groups making strangeness production an important tool in the search and discovery of this primordial state of matter present in the Universe before matter in its present form was formed. We close by looking at both the ongoing research that increases the reach of this observable to LHC energy scale $pp$ collisions, and propose an interpretation of these unexpected results.

   hep-phnucl-thEur.Phys.J.ST(2020)·40 citations
10. 10*

    Charge asymmetry dependence of flow and a novel correlator to detect the chiral magnetic wave in a multiphase transport model

    Diyu Shen🇨🇳 · Jinhui Chen🇨🇳 · Guoliang Ma🇨🇳 · Yu-Gang Ma🇨🇳 · Qiye Shou🇨🇳 · Song Zhang🇨🇳 · Chen Zhong🇨🇳

    In a multiphase transport model with the initial electric quadrupole moment, we studied and discussed the charge asymmetry ($A_{\mathrm{ch}}$) dependence of flow at varied kinematic windows in semi-central Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV. We then proposed a novel correlator $W$ which specially focuses on the difference of elliptic flow between positively and negatively charged hadrons induced by the chiral magnetic wave and, more importantly, is irrelevant to the ambiguous $A_{\mathrm{ch}}$. We found that the distribution of the second order correlator $W_2$ displays a convex structure in the absence of the quadrupole and a concave shape in the presence of the quadrupole. We also studied the response of $W_n$ for both signal and resonance background in a toy model and in analytical calculation. Such a method provides a new way to detect the chiral magnetic wave.

    hep-phnucl-exPRC(2019)·10 citations
11. 11*

    Recent probes of standard and non-standard neutrino physics with nuclei

    D.K. Papoulias🇪🇸 · T.S. Kosmas🇬🇷 · Y. Kuno🇯🇵

    We review standard and non-standard neutrino physics probes that are based on nuclear measurements. We pay special attention on the discussion of prospects to extract new physics at prominent rare event measurements looking for neutrino-nucleus scattering, such as the coherent elastic neutrino-nucleus scattering (CE$\nu$NS) that may involve lepton flavor violation (LFV) in neutral-currents (NC). For the latter processes several appreciably sensitive experiments are currently pursued or have been planed to operate in the near future, like the COHERENT, CONUS, CONNIE, MINER, TEXONO, RED100, vGEN, Ricochet, NUCLEUS etc. We provide a thorough discussion on phenomenological and theoretical studies, in particular those referring to the nuclear physics aspects in order to provide accurate predictions for the relevant experiments. Motivated by the recent discovery of CE$\nu$NS at the COHERENT experiment and the active experimental efforts for a new measurement at reactor-based experiments, we summarize the current status of the constraints as well as the future sensitivities on nuclear and electroweak physics parameters, non-standard interactions, electromagnetic neutrino properties, sterile neutrinos and simplified scenarios with novel vector $Z^{\prime }$ or scalar $\varphi$ mediators. Indirect and direct connections of \cevns with astrophysics, direct Dark Matter detection and charge lepton flavor violating processes are also discussed.

    hep-phFront.in Phys.(2019)·70 citations
12. 12*

    Chiral magnetic response to arbitrary axial imbalance

    Miklos Horvath🇨🇳 · Defu Hou🇨🇳 · Jinfeng Liao🇺🇸 · Hai-cang Ren🇺🇸

    The response of chiral fermions to time and space dependent axial imbalance & constant magnetic field is analyzed. The axialvector-vector-vector (AVV) three-point function is studied using a real-time approach at finite temperature in the weak external field approximation. The chiral magnetic conductivity is given analytically for noninteracting fermions. It is pointed out that local charge conservation plays an important role when the axial imbalance is inhomogeneous. Proper regularization is needed which makes the constant axial imbalance limit delicate: for static but spatially oscillating chiral charge the current of the chiral magnetic effect (CME) vanishes. In the homogeneous (but possible time-dependent) limit of the axial imbalance the CME current is determined solely by the chiral anomaly. As a phenomenological consequence, the observability of the charge asymmetry caused by the CME turns out to be a matter of interplay between various scales of the system. Possible plasma instabilities resulting from the gradient corrections to the CME current are also pointed out.

    hep-phcond-mat.str-elhep-thnucl-thPRD(2020)·18 citations
13. 13*

    Spectrum of fully-heavy tetraquarks from a diquark+antidiquark perspective

    M. A. Bedolla🇲🇽 · J. Ferretti🇺🇸 · C. D. Roberts🇨🇳 · E. Santopinto🇮🇹

    Using a relativized diquark model Hamiltonian, we calculate the masses of $J^{PC}=0^{++}$ ground-state tetraquarks in the following systems: $bs\bar{b}\bar{s}$, $bb\bar{n}\bar{n}$ ($n=u,d$), $bb\bar{s}\bar{s}$, $cc\bar{c}\bar{c}$, $bb\bar{b}\bar{b}$, $bc\bar{b}\bar{c}$ and $bb\bar{c}\bar{c}$. We also compute extensive spectra for the fully-heavy quark flavour combinations. Finally, as a test of the diquark model approach, we compute the masses of fully-heavy baryons in the diquark model. Our results may be compared soon to the forthcoming experimental data for fully-heavy three-quark systems.

    hep-phhep-exhep-latnucl-ex+1EPJC(2020)·190 citations
14. 14*

    Same-Sign Tetralepton Signature at Large Hadron Collider, and future $pp$ Collider

    Eung Jin Chun🇰🇷 · Sarif Khan🇩🇪 · Sanjoy Mandal🇮🇳 · Manimala Mitra🇮🇳 · Sujay Shil🇮🇳

    We analyze a novel signature of the type II seesaw model - same-sign tetra-lepton signal arising from the mixing of neutral Higgs bosons and their subsequent decays to singly and doubly charged Higgs bosons. For this, we consider wide ranges of the triplet vacuum expectation value (vev) and Yukawa couplings, that are consistent with the observed neutrino masses and mixing as well as the LHC search limits. We find that a doubly charged Higgs boson with mass around 250 GeV and triplet vev around $10^{-4}-10^{-2}$ GeV can give significantly large number of events through it decay to same-sign $W$ gauge bosons at High-Luminosity LHC with $3000{\text{fb}}^{-1}$ of data. We also pursue the analysis for a future hadron collider with the c.m. energy of 100 TeV. Considering a heavy Higgs boson around 900 GeV and an intermediate region of the triplet vev, where both same-sign dilepton and gauge boson decays can occur, we identify a limited range of the parameters where the number of same-sign tetra-lepton events are as large as 1000.

    hep-phPRD(2020)·21 citations
15. 15*

    The SU(3) Vector Currents in BChPT x 1/Nc

    Ishara P. Fernando🇺🇸 · Jose L. Goity🇺🇸

    Baryon Chiral Perturbation Theory (BChPT) combined with the 1/Nc expansion is applied to the SU(3) vector currents. In terms of the xi power counting linking the low energy and 1/Nc expansions according to O(xi) = O(p) = O(1/Nc), the study is carried out to next-to-next-to-leading order, and it includes SU(3) breaking corrections to the |Delta S|= 1 vector charges, charge radii, and magnetic moments and radii. The results are obtained for generic Nc, allowing for investigating the various scalings in Nc.

    hep-phPRD(2020)·11 citations
16. 16*

    A scalar potential from gauge condensation and its implications

    Eung Jin Chun🇰🇷 · Chengcheng Han🇰🇷

    We consider a scalar field $\varphi$ whose coupling to the kinetic term of a non-abelian gauge field is set at an UV scale $M$. Then the confinement of the gauge sector will induce a $\varphi$-dependent vacuum energy which generates a dimensionful potential for the scalar. It provides a good example of dynamical generation of a new physics scale below $M$ through the vacuum expectation value $⟨\varphi ⟩$. This mechanism may shed light on the origin of dark matter, or spontaneous symmetry breaking applicable to the electroweak symmetry.

    hep-phhep-thEPJC(2020)·3 citations
17. 17*

    Non-leptonic beauty baryon decays and $CP$-asymmetries based on $SU(3)$-Flavor analysis

    Shibasis Roy🇮🇳 · Rahul Sinha🇮🇳 · N.G. Deshpande🇺🇸

    We consider hadronic weak decays of beauty-baryons into charmless baryons and pseudoscalar mesons in a general framework based on $SU(3)$ decomposition of the decay amplitudes. The advantage of the approach lies in the ability to perform an $SU(3)$ analysis of these decays without any particular set of dynamical assumptions while accounting for the effects of an arbitrarily broken $SU(3)$ flavor symmetry. Dictated by the symmetries of the effective Hamiltonian that allow us to relate or neglect reduced $SU(3)$ amplitudes, we derive several sum rule relations between amplitudes and relations between $CP$ asymmetries in these decays and identify those that hold even if $SU(3)$ is broken.

    hep-phhep-exPRD(2020)·27 citations
18. 18*

    Neutrino masses beyond the minimal seesaw

    Ricardo Cepedello🇪🇸 · Renato Fonseca🇨🇿 · Martin Hirsch🇪🇸

    The simplest possibility to generate small Majorana neutrino masses is the seesaw mechanism. However, the smallness of the observed neutrino masses can also be understood, if neutrino masses are generated by higher-dimensional operators and/or at higher loop level. In this talk recent work on systematic classifications of higher-dimensional and radiative neutrino mass models is summarized. Two particular classes of special genuine loop diagrams, i.e. diagrams which can lead to genuine neutrino mass models only under some specific, well-defined conditions, are also discussed.

    hep-phJ.Phys.Conf.Ser.(2020)·7 citations
19. 19*

    The dipole picture and the non-relativistic expansion

    Miguel Ángel Escobedo🇪🇸 · Tuomas Lappi🇫🇮

    We study exclusive quarkonium production in the dipole picture at next-to-leading order (NLO) accuracy, using the non-relativistic expansion for the quarkonium wavefunction. This process offers one of the best ways to obtain information about gluon distributions at small $x$, in ultraperipheral heavy ion collisions and in deep inelastic scattering. The quarkonium light cone wave functions needed in the dipole picture have typically been available only at tree level, either in phenomenological models or in the nonrelativistic limit. In this paper, we discuss the compatibility of the dipole approach and the non-relativistic expansion and compute NLO relativistic corrections to the quarkonium light-cone wave function in light-cone gauge. Using these corrections we recover results for the NLO decay width of quarkonium to $e^{+}{e}^{-}$ and we check that the non-relativistic expansion is consistent with ERBL evolution and with B-JIMWLK evolution of the target. The results presented here will allow computing the exclusive quarkonium production rate at NLO once the one loop photon wave function with massive quarks, currently under investigation, is known.

    hep-phnucl-thPRD(2020)·23 citations
20. 20*

    Gravitational Waves from Phase Transition in Minimal SUSY $U(1{)}_{B-L}$ Model

    Naoyuki Haba🇯🇵 · Toshifumi Yamada🇯🇵

    Many extensions of the Standard Model include a new $U(1)$ gauge group that is broken spontaneously at a scale much above TeV. If a $U(1)$-breaking phase transition occurs at nucleation temperature of $O(100)$-$O(1000)$~TeV, it can generate stochastic gravitational waves in $O(10)$-$O(100)$ Hz range if ${\beta }_{\mathrm{n}}/H_{\mathrm{n}}=1000$, which can be detected by ground-based detectors. Meanwhile, supersymmetry (SUSY) may play a crucial role in the dynamics of such high-scale $U(1)$ gauge symmetry breaking, because SUSY breaking scale is expected to be at TeV to solve the hierarchy problem. In this paper, we study the phase transition of $U(1)$ gauge symmetry breaking in a SUSY model in the SUSY limit. We consider a particular example, the minimal SUSY $U(1{)}_{B-L}$ model. We derive the finite temperature effective potential of the model in the SUSY limit, study a $U(1{)}_{B-L}$-breaking phase transition, and estimate gravitational waves generated from it.

    hep-phPRD(2020)·22 citations
21. 21*

    Jet quenching test of the QCD matter created at RHIC and the LHC needs opacity-resummed medium induced radiation

    Xabier Feal🇪🇸 · Carlos A. Salgado🇪🇸 · Ricardo A. Vazquez🇪🇸

    After almost two decades of investigation, jet quenching has become a fundamental tool to study the properties of the QCD matter produced in high-energy nuclear collisions. Despite the large progress in both experimental and theoretical tools, several unknowns remain to be solved. In particular the systematics of the QCD matter parameters extracted at different energies and centralities is still puzzling. On the other hand, a lot of attention has been put in the last few years to a correct resummation of the multiple scatterings that the particles of the jet suffer when traversing the QCD matter. Present formalisms have substantially improved the multiple-soft or single hard scattering approximations, common in the last twenty years. We show here that medium parameters extracted with full resummed medium-induced gluon radiation spectra significantly differ from these two extreme approximations, providing a natural systematics for different collision energies and centralities, with no inconsistencies. For the case of the full resummation this ensures that the density of scattering centers as a function of the temperature qualitatively agree with the equation of state computed in lattice QCD.

    hep-phnucl-thPLB(2021)·49 citations
22. 22*

    Time-evolution of magnetic field in hot nuclear matter with fluctuating topological charge

    Kirill Tuchin🇺🇸

    The time-evolution of the magnetic field in hot homogeneous nuclear matter has two qualitatively different stages separated by the sphaleron transition time ${\tau }_c$. At early times the axial chemical potential and the corresponding chiral conductivity ${\sigma }_{\chi }$ are slow functions of time. The soft chiral modes $k<{\sigma }_{\chi }$ of the magnetic field grow exponentially with time, which is known as the chiral instability. At later times ${\sigma }_{\chi }$ fluctuates due to the sphaleron transitions and can be regarded as a random process. It is argued that the average magnetic field is exponentially damped at later times. The time-evolution of the average magnetic energy is more complicated and depends on the electrical conductivity of the chiral matter but does not depend on chirality. It exhibits instability only if the matter is a poor electrical conductor, such as the quark-gluon plasma near the critical temperature. The precise conditions for the instability and the growth rate of the unstable modes are derived.

    hep-phnucl-thPRC(2020)·12 citations
23. 23*

    Isospin-Violating Contributions to ${ϵ}^{\prime }/ϵ$

    V. Cirigliano🇺🇸 · H. Gisbert🇩🇪 · A. Pich🇪🇸 · A. Rodríguez-Sánchez🇸🇪

    The known isospin-breaking contributions to the $K\to \pi \pi$ amplitudes are reanalyzed, taking into account our current understanding of the quark masses and the relevant non-perturbative inputs. We present a complete numerical reappraisal of the direct CP-violating ratio ${ϵ}^{\prime }/ϵ$, where these corrections play a quite significant role. We obtain the Standard Model prediction $\text{Re}\left({ϵ}^{\prime }/ϵ\right)=\left(14\pm 5\right)\cdot 10^{-4}$, which is in very good agreement with the measured ratio. The uncertainty, which has been estimated conservatively, is dominated by our current ignorance about $1/N_C$-suppressed contributions to some relevant chiral-perturbation-theory low-energy constants.

    hep-phhep-exhep-latJHEP(2020)·61 citations
24. 24*

    Decaying Sterile Neutrinos and the Short Baseline Oscillation Anomalies

    Mona Dentler🇩🇪 · Ivan Esteban🇪🇸 · Joachim Kopp🇨🇭 · Pedro Machado🇺🇸

    The MiniBooNE experiment has observed a significant excess of electron neutrinos in a muon neutrino beam at source-detector distances too short to be compatible with standard neutrino oscillations. The most straightforward explanation for this signal in terms of oscillations between Standard Model neutrinos and a new, sterile, neutrino, is disfavored by null results from experiments looking for muon neutrino disappearance. Here, we discuss the possibility that MiniBooNE data are instead explained by a sterile neutrino that decays quickly back into active neutrinos plus a light boson. The flavor composition of the secondary neutrinos is determined by the sterile neutrino mixing angles, and we show that the data is best explained if the sterile neutrino mixes mostly with electron neutrinos. The preferred range for the mass of the sterile neutrino is between 100 eV and 1 keV. We argue that the model can easily satisfy cosmological constraints because it has the "secret interactions" mechanism built-in. Accommodating in addition to the MiniBooNE anomaly also the LSND, reactor, and gallium anomalies is possible, but in this case the model needs to be extended to avoid cosmological limits.

    hep-phhep-exPRD(2020)·80 citations
25. 25*

    QCD Baryogenesis

    Djuna Croon🇨🇦 · Jessica N. Howard🇺🇸 · Seyda Ipek🇺🇸 · Timothy M.P. Tait🇺🇸

    We explore a simple model which naturally explains the observed baryon asymmetry of the Universe. In this model the strong coupling is promoted to a dynamical quantity, which evolves through the vacuum expectation value of a singlet scalar field that mixes with the Higgs field. In the resulting cosmic history, QCD confinement and electroweak symmetry breaking initially occur simultaneously close to the weak scale. The early confinement triggers the axion to roll toward its minimum, which creates a chemical potential between baryons and antibaryons through the interactions of the ${\eta }^{\prime }$ meson, resulting in spontaneous baryogenesis. The electroweak sphalerons are sharply switched off after confinement and the baryon asymmetry is frozen in. Subsequently, evolution of the Higgs vacuum expectation value (which is modified in the confined phase) triggers a relaxation to a Standard Model-like vacuum. We identify viable regions of parameter space, and describe various experimental probes, including current and future collider constraints, and gravitational wave phenomenology.

    hep-phastro-ph.COhep-exPRD(2020)·61 citations
26. 26*

    Transverse momentum dependent parton densities in a proton from the generalized DAS approach

    A.V. Kotikov🇷🇺 · A.V. Lipatov🇷🇺 · B.G. Shaikhatdenov🇷🇺 · P. Zhang🇨🇳

    We use the Bessel-inspired behavior of parton densities at small Bjorken $x$ values, obtained in the case of the flat initial conditions for DGLAP evolution equations in the double scaling QCD approximation (DAS), to evaluate the transverse momentum dependent (TMD, or unintegrated) quark and gluon distribution functions in a proton. The calculations are performed analytically using the Kimber-Martin-Ryskin (KMR) prescription with different implementation of kinematical constraint, reflecting the angular and strong ordering conditions. The relations between the differential and integral formulation of the KMR approach is discussed. Several phenomenological applications of the proposed TMD parton densities to the LHC processes are given.

    hep-phJHEP(2020)·16 citations
27. 27*

    On The Decaying-Sterile Neutrino Solution to the Electron (Anti)Neutrino Appearance Anomalies

    André de Gouvêa🇺🇸 · O. L. G. Peres🇧🇷 · Suprabh Prakash🇧🇷 · G. V. Stenico🇧🇷

    We explore the hypothesis that the unexplained data from LSND and MiniBooNE are evidence for a new, heavy neutrino mass-eigenstate that mixes with the muon-type neutrino and decays into an electron-type neutrino and a new, very light scalar particle. We consider two different decay scenarios, one with Majorana neutrinos, one with Dirac neutrinos; both fit the data equally well. We find a reasonable, albeit not excellent, fit to the data of MiniBooNE and LSND. The decaying-sterile-neutrino hypothesis, however, cleanly evades constraints from disappearance searches and precision measurements of leptonic meson decays, as long as $1\mathrm{MeV}\gtrsim m_4\gtrsim 10$~keV. The SBN program at Fermilab should be able to definitively test the decaying-sterile-neutrino hypothesis.

    hep-phhep-exJHEP(2020)·77 citations
28. 28*

    Dark Matter Cores and Cusps in Spiral Galaxies and their Explanations

    Manoj Kaplinghat🇺🇸 · Tao Ren🇺🇸 · Hai-Bo Yu🇺🇸

    We compare proposed solutions to the core vs cusp issue of spiral galaxies, which has also been framed as a diversity problem, and demonstrate that the cuspiness of dark matter halos is correlated with the stellar surface brightness. We compare the rotation curve fits to the SPARC sample from a self-interacting dark matter (SIDM) model, which self-consistently includes the impact of baryons on the halo profile, and hydrodynamical N-body simulations with cold dark matter (CDM). The SIDM model predicts a strong correlation between the core size and the stellar surface density, and it provides the best global fit to the data. The CDM simulations without strong baryonic feedback effects fail to explain the large dark matter cores seen in low surface brightness galaxies. On the other hand, with strong feedback, CDM simulations do not produce galaxy analogs with high stellar and dark matter densities, and therefore they have trouble in explaining the rotation curves of high surface brightness galaxies. This implies that current feedback implementations need to be modified. We also explicitly show how the concentration-mass and stellar-to-halo mass relations together lead to a radial acceleration relation (RAR) in an averaged sense, and reiterate the point that the RAR does not capture the diversity of galaxy rotation curves in the inner regions. These results make a strong case for SIDM as the explanation for the cores and cusps of field galaxies.

    ↳ astro-ph.GAastro-ph.COhep-phJCAP(2020)·96 citations
29. 29*

    Observation of a vector charmoniumlike state in $e^{+}{e}^{-}\to D_s^{+}{D}_{s1}(2536{)}^{-}+c.c.$

    Belle Collaboration: S. Jia · C. P. Shen · C. Z. Yuan · X. L. Wang · I. Adachi · H. Aihara · D. M. Asner · H. Atmacan · V. Aulchenko · R. Ayad · V. Babu · I. Badhrees and 161 other authors

    Using a data sample of 921.9 fb${}^{-1}$ collected with the Belle detector, we study the process of $e^{+}{e}^{-}\to D_s^{+}{D}_{s1}(2536{)}^{-}+c.c.$ via initial-state radiation. We report the first observation of a vector charmoniumlike state decaying to $D_s^{+}{D}_{s1}(2536{)}^{-}+c.c.$ with a significance of 5.9$\sigma$, including the systematic uncertainties. The measured mass and width are $(4625.9_{-6.0}^{+6.2}(stat.)\pm 0.4(syst.))\mathrm{MeV}/c^2$ and $(49.8_{-11.5}^{+13.9}(stat.)\pm 4.0(syst.))\mathrm{MeV}$, respectively. The product of the $e^{+}{e}^{-}\to D_s^{+}{D}_{s1}(2536{)}^{-}+c.c.$ cross section and the branching fraction of $D_{s1}(2536{)}^{-}\to {\bar{D}}^{\ast 0}{K}^{-}$ is measured from the $D_s{\bar{D}}_{s1}(2536)$ threshold to 5.59~GeV.

    ↳ hep-exhep-phPRD(2019)·52 citations
30. 30*

    Coherent Elastic Neutrino-Nucleus Scattering at the European Spallation Source

    D. Baxter🇺🇸 · J.I. Collar🇺🇸 · P. Coloma🇪🇸 · C.E. Dahl🇺🇸 · I. Esteban🇪🇸 · P. Ferrario🇪🇸 · J.J. Gomez-Cadenas🇪🇸 · M. C. Gonzalez-Garcia🇪🇸 · A.R.L. Kavner🇺🇸 · C.M. Lewis🇺🇸 · F. Monrabal🇪🇸 · J. Muñoz Vidal🇪🇸 and 3 other authors

    The European Spallation Source (ESS), presently well on its way to completion, will soon provide the most intense neutron beams for multi-disciplinary science. Fortuitously, it will also generate the largest pulsed neutrino flux suitable for the detection of Coherent Elastic Neutrino-Nucleus Scattering (CE$\nu$NS), a process recently measured for the first time at ORNL's Spallation Neutron Source. We describe innovative detector technologies maximally able to profit from the order-of-magnitude increase in neutrino flux provided by the ESS, along with their sensitivity to a rich particle physics phenomenology accessible through high-statistics, precision CE$\nu$NS measurements.

    ↳ physics.ins-dethep-exhep-phnucl-exJHEP(2020)·127 citations
31. 31*

    Nonperturbative renormalization of staple-shaped Wilson line operators in lattice QCD

    Phiala Shanahan🇺🇸 · Michael L. Wagman🇺🇸 · Yong Zhao🇺🇸

    Quark bilinear operators with staple-shaped Wilson lines are used to study transverse-momentum-dependent parton distribution functions (TMDPDFs) from lattice quantum chromodynamics (QCD). Here, the renormalization factors for the isovector operators, including all mixings between operators with different Dirac structures, are computed nonperturbatively in the regularization-independent momentum subtraction scheme for the first time. This study is undertaken in quenched QCD with three different lattice spacings. With Wilson flow applied to the gauge fields in the calculations, the operator mixing pattern due to chiral symmetry breaking with the lattice regularization is found to be significantly different from that predicted by one-loop lattice perturbation theory calculations. These results constitute a critical step towards the systematic extraction of TMDPDFs from lattice QCD.

    ↳ hep-lathep-phnucl-thPRD(2020)·80 citations
32. 32*

    Probing the partonic degrees of freedom in high multiplicity p-Pb collisions at $\sqrt{s_{NN}}=$ 5.02 TeV

    Wenbin Zhao🇨🇳 · Che Ming Ko🇺🇸 · Yu-Xin Liu🇨🇳 · Guang-You Qin🇨🇳 · Huichao Song🇨🇳

    We investigate the role of partonic degrees of freedom in high multiplicity p-Pb collisions at $\sqrt{s_{NN}}=$ 5.02 TeV carried out at the Large Hadron Collider (LHC) by studying the production and collective flow of identified hadrons at intermediate $p_T$ via the coalescence of soft and hard partons generated from viscous hydrodynamics (VISH2+1) and the energy loss model (LBT), respectively. We find that combining the intermediate $p_T$ hadrons from the coalescence with the low $p_T$ hadrons from hydrodynamics and high $p_T$ hadrons from the jet fragmentation, our Hydro-Coal-Frag model provides a nice description of the measured $p_T$-spectra and the differential elliptic flow $v_2(p_T)$ of pions, kaons and protons over the $p_T$ range from 0 to 6 GeV. We further demonstrate the necessity of including the quark coalescence contribution to reproduce the experimentally observed approximate number of constituent quark scaling of hadron $v_2$ at intermediate $p_T$. Our results thus indicate the importance of partonic degrees of freedom and also hint at the possible formation of quark-gluon plasma in high multiplicity p+Pb collisions at the LHC.

    ↳ nucl-thhep-phnucl-exPRL(2020)·100 citations
33. 33*

    Pion-nucleon scattering to $\mathcal{O}(p^3)$ in heavy baryon SU(3) chiral perturbation theory

    Bo-Lin Huang🇨🇳 · Jing Ou-Yang🇨🇳

    We calculate the complete $T$-matrices of pion-nucleon ($\pi N$) scattering to the third order in heavy baryon SU(3) chiral perturbation theory. The baryon mass in the chiral limit $M_0$ and the low-energy constants are determined by fitting to phase shifts of $\pi N$ and the experimental octet-baryon masses simultaneously. By using these constants, we obtain the pion-nucleon sigma terms, ${\sigma }_{\pi N}=(34.57\pm 11.85)$ MeV. We also find that a very small strangeness content of the proton, $y\simeq 0$. The scattering lengths and the scattering volumes are predicted, which turn out to be in good agreement with those of other approaches and the available experiment data. The contributions from the third-order amplitudes are discussed in detail. We find that the contributions from the internal kaon lines of one-loop diagrams and the counterterms of the third order are sizeable. In addition, the issue of convergence is also discussed.

    ↳ nucl-thhep-phPRD(2020)·16 citations
34. 34*

    Hyperon interaction with dense nuclear matter and link to neutron stars

    Laura Tolos🇩🇪

    The theoretical status of the hyperon-nucleon and hyperon-hyperon interactions is reviewed, paying a special attention to chiral effective field theories. Results on hyperons in dense matter are presented and the consequences for the properties of neutron stars are analyzed.

    ↳ nucl-thastro-ph.HEhep-phSpringer Proc.Phys.(2020)·0 citations
35. 35*

    Confinement/deconfinement phase transition and dual Meissner effect in SU(3) Yang-Mills theory

    Akihiro Shibata🇯🇵 · Kei-Ichi Kondo🇯🇵 · Seikou Kato🇯🇵

    We investigate the confinement-deconfinement phase transition at finite temperature of the SU(3) Yang-Mills(YM) theory on the lattice from a viewpoint of the dual superconductor picture based on the novel reformulation of the YM theory. In particular, we compare the conventional Abelian dual superconductor picture with the non-Abelian dual superconductor picture proposed in our previous works as the mechanism of quark confinement in the SU(3) YM theory. For the SU(3) YM theory, the reformulation allows two possible options called maximal and minimal. The maximal option corresponds to the manifestly gauge-invariant extension of the Abelian projection scheme, while the minimal option is really new to give the non-Abelian dual superconductor picture. Keeping these differences in mind, we present the numerical evidences that the confinement/deconfinement phase transition is caused by appearance/disappearance of the dual Meissner effects. First, we measure the Polyakov loop average at various temperatures to determine the critical temperature separating the low-temperature confined phase and the high-temperature deconfined phase. Second, we measure the static quark-antiquark potential. Third, we measure the chromoelectric and chromomagnetic flux created by a pair of quark and antiquark at temperatures below and above the critical temperature. We observe no more squeezing of the chromoelectric flux tube above the critical temperature. Finally, we measure the associated magnetic--monopole current induced around the chromo-flux tube and observe that the confinement/deconfinement phase transition is associated with the appearance/disappearance of the induced magnetic--monopole current, respectively. We confirm that these results are also obtained by the restricted field alone in both options, indicating the restricted field dominance in quark confinement at finite temperature.

    ↳ hep-lathep-ph4 citations
36. 36*

    Constraints on Dark Energy from Inflation and the Swampland Conjectures

    Jacob M. Leedom🇺🇸

    We discuss the prospects of measuring deviations of the dark energy equation of state from w=-1 by using the swampland conjectures to relate inflationary models to quintessence scenarios. This note is based on work done by the author with H. Murayama and C. Chiang arXiv:1811.01987.

    ↳ hep-thastro-ph.COhep-ph3 citations
37. 37*

    Nucleon/Hyperon Physics at BES

    Stephen Lars Olsen🇨🇳

    The year 2019 marks the 30th anniversary of BES and the 100th anniversary of Rutherford's discovery of the proton. In spite of the fact that when BES operations started the proton was already 70 years old and the strange hyperons were all over 25, BES continues to make important and unique measurements of nucleon and hyperon properties, including some interesting discoveries.

    ↳ hep-exhep-phnucl-ex1 citation
38. 38*

    $K^{-}p$ Correlation Function from High-Energy Nuclear Collisions and Chiral SU(3) Dynamics

    Yuki Kamiya🇨🇳 · Tetsuo Hyodo🇯🇵 · Kenji Morita🇯🇵 · Akira Ohnishi🇯🇵 · Wolfram Weise🇩🇪

    The two-particle momentum correlation function of a K^-p pair from high-energy nuclear collisions is evaluated in the KbarN-piSigma-piLambda coupled-channels framework. The effects of all coupled channels together with the Coulomb potential and the threshold energy difference between K^-p and Kbar0 n are treated completely for the first time. Realistic potentials based on the chiral SU(3) dynamics are used which fit the available scattering data. The recently measured correlation function is found to be well reproduced by allowing variations of the source size and the relative weight of the source function of piSigma with respect to that of KbarN. The predicted K^-p correlation function from larger systems, which is less affected by the piSigma source function, indicates that the investigation of its source size dependence is useful in providing further constraints in the study of the KbarN interaction.

    ↳ nucl-thhep-phPRL(2020)·85 citations
39. 39*

    Theory Summary at Strangeness in Quark Matter 2019

    Jacquelyn Noronha-Hostler🇺🇸

    This is the theory summary of Strangeness in Quark Matter 2019 conference. Results include the state-of-the-art updates to the Quantum Chromodynamics (QCD) phase diagram with contributions both from heavy-ion collisions and nuclear astrophysics, studies on the QCD freeze-out lines, and several aspects regarding small systems including collectivity, heavy flavor dynamics, strangeness, and hard probes.

    ↳ nucl-thastro-ph.HEhep-lathep-phSpringer Proc.Phys.(2020)·2 citations
40. 40*

    D meson sensitivity to a system size scan at LHC

    Roland Katz🇫🇷 · Jacquelyn Noronha-Hostler🇺🇸 · Caio A. G. Prado🇨🇳 · Alexandre A. P. Suaide🇧🇷

    Experimental measurements in pA collisions indicate no D meson suppression ($R_{\mathrm{pPb}}\sim 1$) but a surprisingly large $v_2$. To better understand these results we propose a system size scan at the LHC involving ${}^{16}$OO, ${}^{40}$ArAr, ${}^{129}$XeXe and ${}^{208}$PbPb collisions. Using Trento+ v-USPhydro+DAB-MOD to make predictions, we find that the $R_{\mathrm{AA}}$ tends towards unity when the system size is decreased, but nonetheless, in the most central collisions $v_2\{2\}$ is almost independent of the colliding system. These results are analyzed in light of path length and initial eccentricity variations.

    ↳ nucl-thhep-exhep-phSpringer Proc.Phys.(2020)·1 citation
41. 41*

    Physics Beyond The Standard Model with Circular Polarization in the CMB and CMB-21cm Cross-Correlation

    Stephon Alexander🇺🇸 · Evan McDonough🇺🇸 · Anthony Pullen🇺🇸 · Bradley Shapiro🇺🇸

    Circular polarization is a relatively unexplored realm of CMB physics. Given the substantial community effort towards building next generation CMB polarization experiments, including those which will be sensitive to circular polarization, it behooves theorists to understand the possible sources and relevant physics of circular polarization, as encoded in the Stokes V parameter. In this work we develop and derive the requisite formalism, namely the Boltzmann hierarchy for V-mode scalar, vector, and tensor, anisotropies. We derive the V-mode anisotropies induced by a general source term, and demonstrate how existing proposals for the generation of V can be incorporated as source terms in the Boltzmann hierarchy. A subset of these effects may be correlated with 21cm intensity; we provide a worked example and derive an estimator to extract this information from observations. We conclude by computing the CMB TV cross-correlation generated by axions, and find a relation between TV and VV spectra in axion models.

    ↳ astro-ph.COgr-qchep-phhep-thJCAP(2020)·17 citations
42. 42*

    A landscape for the cosmological constant and the Higgs mass

    Parsa Ghorbani🇮🇹 · Alessandro Strumia🇮🇹 · Daniele Teresi🇮🇹

    The cosmological constant and the Higgs mass seem unnaturally small and anthropically selected. We show that both can be efficiently scanned in Quantum Field Theories with a large enough number of vacua controllable thanks to approximated ${\mathbb{Z}}_2$ symmetries (even for Coleman-Weinberg potentials). We find that vacuum decay in a landscape implies weaker bounds than previously estimated. Special vacua where one light scalar is accidentally light avoid catastrophic vacuum decay if its self-cubic is absent. This is what happens for the Higgs doublet, thanks to gauge invariance. Yukawa couplings can be efficiently scanned, as suggested by anthropic boundaries on light quark masses. Finally, we suggest that the lack of predictivity of landscapes can be mitigated if their probability distributions are non-Gaussian (possibly even fractal).

    ↳ hep-thhep-phJHEP(2020)·9 citations
43. 43*

    Gravitational waves in warped compactifications

    David Andriot🇦🇹 · Dimitrios Tsimpis🇫🇷

    We study gravitational waves propagating on a warped Minkowski space-time with D-4 compact extra dimensions. While Kaluza-Klein scales are typically too high for any current detection, we analyse how the warp factor changes the Kaluza-Klein spectrum of gravitational waves. To that end we provide a complete and explicit expression for the warp factor, as well as the Green's function, on a d-dimensional torus. This expression differs from that of braneworld models and should find further uses in string compactifications. We then evaluate the Kaluza-Klein spectrum of gravitational waves. Our preliminary numerical results indicate not only a deviation from the standard toroidal spectrum, but also that the first masses get lowered due to the warp factor.

    ↳ hep-thastro-ph.COastro-ph.HEgr-qc+1JHEP(2020)·42 citations
44. 44*

    Gauge Invariance for Classical Massless Particles with Spin

    Jacob A. Barandes🇺🇸

    Wigner's quantum-mechanical classification of particle-types in terms of irreducible representations of the Poincaré group has a classical analogue, which we extend in this paper. We study the compactness properties of the resulting phase spaces at fixed energy, and show that in order for a classical massless particle to be physically sensible, its phase space must feature a classical-particle counterpart of electromagnetic gauge invariance. By examining the connection between massless and massive particles in the massless limit, we also derive a classical-particle version of the Higgs mechanism.

    ↳ physics.class-phhep-phhep-thFound.Phys.(2021)·4 citations
45. 45*

    Higgs potential and fundamental physics

    Ivan Melo🇸🇰

    Physics associated with the Higgs field potential is rich and interesting and deserves a concise summary for a broader audience to appreciate the beauty and the challenges of this subject. We discuss the role of the Higgs potential in particle physics, in particular in the spontaneous symmetry breaking and in the mass generation using an example of a simple reflection symmetry, then continue with the temperature and quantum corrections to the potential which lead us to the naturalness problem and the vacuum stability.

    ↳ physics.gen-phhep-phEur.J.Phys.(2017)·24 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.