Mon·Oct 28, 2019Monday·October 28, 2019

1. 01*

   TMD Soft Function from Large-Momentum Effective Theory

   Xiangdong Ji🇺🇸 · Yizhuang Liu🇨🇳 · Yu-Sheng Liu🇨🇳

   We study Euclidean formulations of the transverse-momentum-dependent (TMD) soft function, which is a cross section for soft gluon radiations involving color charges moving in two conjugate lightcone directions in quantum chromodynamics. We show it is related to a special form factor of a pair of color sources traveling with nearly-lightlike velocities, which can be matched to TMD physical observables in semi-inclusive deep-inelastic scattering and Drell-Yan process in the framework of large momentum effective theory. It can also be extracted by combining a large-momentum form factor of light meson and its leading TMD wave function. These formulations are useful for initiating nonperturbative calculations of this useful quantity.

   hep-phhep-exhep-latnucl-ex+1NPB(2020)·106 citations
2. 02*

   Reinterpreting the results of the LHC with MadAnalysis 5: uncertainties and higher-luminosity estimates

   Jack Y. Araz🇨🇦 · Mariana Frank🇨🇦 · Benjamin Fuks🇫🇷

   The MadAnalysis 5 framework can be used to assess the potential of various LHC analyses for unravelling any specific new physics signal. We present an extension of the LHC reinterpretation capabilities of the programme allowing for the inclusion of theoretical and systematical uncertainties on the signal in the reinterpretation procedure. We have implemented extra methods dedicated to the extrapolation of the impact of a given analysis to higher luminosities, including various options for the treatment of the errors. As an application, we study three classes of new physics models. We first focus on a simplified model in which the Standard Model is supplemented by a gluino and a neutralino. We show that uncertainties could in particular degrade the bounds by several hundreds of GeV when considering 3000 fb${}^{-1}$ of future LHC data. We next investigate another supersymmetry-inspired simplified model, in which the Standard Model is extended by a first generation squark species and a neutralino. We reach similar conclusions. Finally, we study a class of s-channel dark matter setups and compare the expectation for two types of scenarios differing in the details of the implementation of the mediation between the dark and Standard Model sectors.

   hep-phEPJC(2020)·56 citations
3. 03*

   Jet angularities in photoproduction at the Electron-Ion Collider

   Elke-Caroline Aschenauer🇺🇸 · Kyle Lee🇺🇸 · B.S. Page🇺🇸 · Felix Ringer🇺🇸

   We consider the one-parameter family of jet substructure observables known as angularities using the specific case of inclusive jets arising from photoproduction events at an Electron-Ion Collider (EIC). We perform numerical calculations at next-to-leading logarithmic accuracy within perturbative QCD and compare our results to PYTHIA 6 predictions. Overall, we find good agreement and conclude that jet substructure observables are feasible at the EIC despite the relatively low jet transverse momentum and particle multiplicities. We investigate the size of subleading power corrections relevant at low energies within the Monte Carlo setup. In order to establish the validity of the Monte Carlo tune, we also perform comparisons to jet shape data at HERA. We further discuss detector requirements necessary for angularity measurements at an EIC, focusing on hadron calorimeter energy and spatial resolutions. Possible applications of precision jet substructure measurements at the EIC include the tuning of Monte Carlo event generators, the extraction of nonperturbative parameters and studies of cold nuclear matter effects.

   hep-phhep-exnucl-exnucl-thPRD(2020)·49 citations
4. 04*

   Identifying the nature of the QCD transition in relativistic collision of heavy nuclei with deep learning

   Yi-Lun Du🇳🇴 · Kai Zhou🇩🇪 · Jan Steinheimer🇩🇪 · Long-Gang Pang🇺🇸 · Anton Motornenko🇩🇪 · Hong-Shi Zong🇨🇳 · Xin-Nian Wang🇨🇳 · Horst Stöcker🇩🇪

   Using deep convolutional neural network (CNN), the nature of the QCD transition can be identified from the final-state pion spectra from hybrid model simulations of heavy-ion collisions that combines a viscous hydrodynamic model with a hadronic cascade "after-burner". Two different types of equations of state (EoS) of the medium are used in the hydrodynamic evolution. The resulting spectra in transverse momentum and azimuthal angle are used as the input data to train the neural network to distinguish different EoS. Different scenarios for the input data are studied and compared in a systematic way. A clear hierarchy is observed in the prediction accuracy when using the event-by-event, cascade-coarse-grained and event-fine-averaged spectra as input for the network, which are about 80%, 90% and 99%, respectively. A comparison with the prediction performance by deep neural network (DNN) with only the normalized pion transverse momentum spectra is also made. High-level features of pion spectra captured by a carefully-trained neural network were found to be able to distinguish the nature of the QCD transition even in a simulation scenario which is close to the experiments.

   hep-phnucl-thEPJC(2020)·74 citations
5. 05*

   S-Wave Single Heavy Baryons with Spin-3/2 at Finite Temperature

   K. Azizi🇮🇷 · A. Türkan🇹🇷

   The thermal behavior of the spectroscopic parameters of the S-wave single heavy baryons ${\Sigma }_Q^{\ast },{\Xi }_Q^{\ast }$ and ${\Omega }_Q^{\ast }$ with spin-3/2 are investigated in QCD at finite temperature. We analyze the variations of the mass and residue of these baryons taking into consideration the contributions of QCD thermal condensates up to dimension eight in Wilson expansion. At finite temperature, due to the breakdown of the Lorentz invariance by the choice of reference frame and presence of an extra $O(3)$ symmetry, some new four-dimensional operators come out in the form of the fermionic and gluonic parts of the energy momentum tensor that are taken into account in the calculations. Our analyses show that at lower temperatures, the parameters of baryons under consideration are not affected by the medium. These parameters, however, show rapid variations with respect to temperature at higher temperatures near to a pseudo-critical temperature, after which the baryons are melted. The results of the masses and residues at $T\to 0$ limit are compatible with the available experimental data and predictions of other theoretical studies.

   hep-phhep-exhep-latEPJC(2020)·10 citations
6. 06*

   $CP$ violation in modular invariant flavor models

   Tatsuo Kobayashi🇯🇵 · Yusuke Shimizu🇯🇵 · Kenta Takagi🇯🇵 · Morimitsu Tanimoto🇯🇵 · Takuya H. Tatsuishi🇯🇵 · Hikaru Uchida🇯🇵

   We study the spontaneous $CP$ violation through the stabilization of the modulus $\tau$ in modular invariant flavor models. The $CP$-invaraiant potentential has the minimum only at $\mathrm{Re}[\tau ]=0$ or 1/2. From this prediction, we study $CP$ violation in modular invariant flavor models. The physical $CP$ phase is vanishing. The important point for the $CP$ conservation is the $T$ transformation in the modular symmetry. One needs the violation of $T$ symmetry to realize the spontaneous $CP$ violation.

   hep-phhep-thPRD(2020)·92 citations
7. 07*

   Constraining the Particle Production Mechanism in Au+Au Collisions at $\sqrt{s_{NN}}=$ 7.7, 27, and 200 GeV Using A Multi Phase Transport Model

   Abhirikshma Nandi🇮🇳 · Lokesh Kumar🇮🇳 · Natasha Sharma🇮🇳

   We study the production of pions, kaons, and (anti)protons in A Multi Phase Transport (AMPT) Model in Au+Au collisions at $\sqrt{s_{NN}}=$ 7.7, 27, and 200 GeV. We present the centrality and energy dependence of various bulk observables such as invariant yields as a function of transverse momentum $p_T$, particle yields $dN/dy$, average transverse momentum $⟨p_T⟩$, and various particle ratios, and compare them with experimental data. Both default and string melting (SM) versions of the AMPT model are used with three different sets of initial conditions. We observe that neither the default nor the SM version of the model could consistently describe the centrality dependence of all observables at the above energies with any one set of initial conditions. The energy dependence behavior of the experimental observables for 0--5\% central collisions is in general better described by the default AMPT model using the modified HIJING parameters for Lund string fragmentation and 3mb parton scattering cross-section. In addition, the kaon production as well as the $K/\pi$ ratio at 7.7 GeV are under predicted by the AMPT model.

   hep-phnucl-exPRC(2020)·17 citations
8. 08*

   A DAMA/Libra-phase2 analysis in terms of WIMP-quark and WIMP-gluon effective interactions up to dimension seven

   Sunghyun Kang🇰🇷 · Stefano Scopel🇰🇷 · Gaurav Tomar (Sogang U.)🇰🇷

   We analyze the DAMA/Libra-phase2 modulation result using a basis of 16 effective operators describing the WIMP interaction with photons, gluons and quarks up to mass dimension seven. For each operator we fix the effective theory at the scale of 2 GeV and parametrize WIMP-quark interactions in terms of two independent couplings for up-type and down-type quarks. We discuss the connection with the non-relativistic limit of the effective theory in terms of operators invariant by Galilean transformations, and the impact of the ensuing momentum-dependent Wilson coefficients due to long-range interactions or light meson poles. Most relativistic operators yield a good fit of the DAMA modulation effect, although for parameters excluded by the constraints from XENON1T and PICO60.

   hep-phastro-ph.CO6 citations
9. 09*

   Weak Decays of Triply Heavy Tetraquarks $b\bar{c}b\bar{q}$

   Ye Xing🇨🇳

   We study lifetimes and weak decays of the triply heavy tetraquarks $b\bar{c}b\bar{q}$. Following the heavy quark expanding(HQE), the lifetimes of tetraquarks $b\bar{c}b\bar{q}$ can be expressed as the summation of different dimension operators. Particularly, we obtain the lifetimes of $b\bar{c}b\bar{q}$ at the next-to-leading order(NLO) given as $\tau (T_{\{\bar{c}\bar{q}\}}^{\{bb\}})=0.70\times 10^{-12}s$. Besides, we construct the weak decays Hamiltonian of $b\bar{c}b\bar{q}$ in hadronic level under the SU(3) flavor symmetry. The discussion of the Hamiltonian can deduce the decay amplitudes and width relations of the tetraquarks. Following the choosing rules, we collect some golden channels for the mesonic decays of tetraquarks, which will be helpful to search for triply heavy tetraquarks $b\bar{c}b\bar{q}$ in future experiments.

   hep-phEPJC(2020)·16 citations
10. 10*

    Large impact parameter behaviour in the CGC/saturation approach: a new non-linear equation

    E. Gotsman (Tel Aviv U.)🇮🇱 · E. Levin (Tel Aviv U./UTFSM)🇮🇱

    In this paper we propose a solution to the long standing problem in the CGC/saturation approach: the power-like fall off of the scattering amplitudes at large $b$. We propose a new non-linear equation, which takes into account random walks both in transverse momenta of the produced gluons and in their impact parameters. We demonstrate, that this equation is in accord with previous attempts to include the diffusion in impact parameters in the BFKL evolution equation. We show in the paper, that the solution to a new equation results in the exponential decrease of the scattering amplitude at large impact parameter, and in the restoration of the Froissart theorem.

    hep-phhep-thPRD(2020)·7 citations
11. 11*

    Hadron-in-jet production at partonic threshold

    Tom Kaufmann🇩🇪 · Xiaohui Liu🇨🇳 · Asmita Mukherjee🇮🇳 · Felix Ringer🇺🇸 · Werner Vogelsang🇩🇪

    We consider the longitudinal momentum distribution of hadrons inside jets in proton-proton collisions. At partonic threshold large double logarithmic corrections arise which need to be resummed to all orders. We develop a factorization formalism within SCET that allows for the joint resummation of threshold and jet radius logarithms. We achieve next-to-leading logarithmic NLL${}^{\prime }$ accuracy by including non-global logarithms in the leading-color approximation. Overall, we find that the threshold resummation leads to a sizable enhancement of the cross section and a reduced QCD scale dependence, suggesting that the all-order resummation can be important for the reliable extraction of fragmentation functions in global analyses when jet substructure data is included.

    hep-phhep-exnucl-exnucl-thJHEP(2020)·12 citations
12. 12*

    Superstring-Inspired Particle Cosmology: Inflation, Neutrino Masses, Leptogenesis, Dark Matter & the SUSY Scale

    John Ellis🇬🇧 · Marcos A. G. Garcia🇪🇸 · Natsumi Nagata🇯🇵 · Dimitri V. Nanopoulos🇺🇸 · Keith A. Olive🇺🇸

    We develop a string-inspired model for particle cosmology, based on a flipped SU(5)$\times$U(1) gauge group formulated in a no-scale supergravity framework. The model realizes Starobinsky-like inflation, which we assume to be followed by strong reheating, with the GUT symmetry being broken subsequently by a light `flaton' field whose decay generates a second stage of reheating. We discuss the production of gravitinos and the non-thermal contribution made by their decays to the density of cold dark matter, which is assumed to be provided by the lightest neutralino. We also discuss the masses of light and heavy neutrinos and leptogenesis. As discussed previously [1], a key rôle is played by a superpotential coupling between the inflaton, matter and GUT Higgs fields, called ${\lambda }_6$. We scan over possible values of ${\lambda }_6$, exploring the correlations between the possible values of observables. We emphasize that the release of entropy during the GUT transition allows large regions of supersymmetry-breaking parameter space that would otherwise lead to severe overdensity of dark matter. Furthermore, we find that the Big Bang nucleosynthesis lower limit on the reheating temperature of $\sim 1$ MeV restricts the supersymmetry-breaking scale to a range $\mathcal{O}(10)$ TeV that is consistent with the absence of supersymmetric particles at the LHC.

    hep-phastro-ph.COJCAP(2020)·36 citations
13. 13*

    Source terms for electroweak baryogenesis in the vev-insertion approximation beyond leading order

    Marieke Postma🇳🇱 · Jorinde van de Vis🇩🇪

    In electroweak baryogenesis the baryon asymmetry of the universe is created during the electroweak phase transition. The quantum transport equations governing the dynamics of the plasma particles can be derived in the vev-insertion approximation, which treats the vev-dependent part of the particle masses as a perturbation. We calculate the next-to-leading order (NLO) contribution to the CP-violating source term and CP-conserving relaxation rate, corresponding to Feynman diagrams for the self-energies with four mass insertions. We consider both a pair of Weyl fermions and a pair of complex scalars, that scatter off the bubble wall. We find: (i) The NLO correction becomes large for $\mathcal{O}(1)$ couplings. If only the Standard Model (SM) Higgs obtains a vev during the phase transition, this implies the vev-insertion approximation breaks down for top quarks. (ii) The resonant enhancement of the source term and relaxation rate, that exists at leading order in the limit of degenerate thermal masses for the fermions/scalars, persists at NLO.

    hep-phastro-ph.COJHEP(2020)·21 citations
14. 14*

    Interpretation of the LHCb $P_c$ States as Hadronic Molecules and Hints of a Narrow $P_c(4380)$

    Meng-Lin Du🇩🇪 · Vadim Baru🇩🇪 · Feng-Kun Guo🇨🇳 · Christoph Hanhart🇩🇪 · Ulf-G. Meißner🇩🇪 · José A. Oller🇪🇸 · Qian Wang🇨🇳

    Three hidden-charm pentaquark $P_c$ states, $P_c(4312)$, $P_c(4440)$, and $P_c(4457)$ were revealed in the ${\Lambda }_b^0\to J/\psi p{K}^{-}$ process measured by LHCb using both run I and run II data. Their nature is under lively discussion, and their quantum numbers have not been determined. We analyze the $J/\psi p$ invariant mass distributions under the assumption that the crossed-channel effects provide a smooth background. For the first time, such an analysis is performed employing a coupled-channel formalism with the scattering potential involving both one-pion exchange as well as short-range operators constrained by heavy quark spin symmetry. We find that the data can be well described in the hadronic molecular picture, which predicts seven ${\Sigma }_c^{(\ast )}{\bar{D}}^{(\ast )}$ molecular states in two spin multiplets, such that the $P_c(4312)$ is mainly a ${\Sigma }_c\bar{D}$ bound state with $J^P=1/2^{-}$, while $P_c(4440)$ and $P_c(4457)$ are ${\Sigma }_c{\bar{D}}^{\ast }$ bound states with quantum numbers $3/2^{-}$ and $1/2^{-}$, respectively. We also show that there is evidence for a narrow ${\Sigma }_c^{\ast }\bar{D}$ bound state in the data which we call $P_c(4380)$, different from the broad one reported by LHCb in 2015. With this state included, all predicted ${\Sigma }_c\bar{D}$, ${\Sigma }_c^{\ast }\bar{D}$, and ${\Sigma }_c{\bar{D}}^{\ast }$ hadronic molecules are seen in the data, while the missing three ${\Sigma }_c^{\ast }{\bar{D}}^{\ast }$ states are expected to be found in future runs of the LHC or in photoproduction experiments.

    hep-phPRL(2020)·212 citations
15. 15*

    Short-distance constraints on hadronic light-by-light scattering in the anomalous magnetic moment of the muon

    Gilberto Colangelo🇨🇭 · Franziska Hagelstein🇨🇭 · Martin Hoferichter🇺🇸 · Laetitia Laub🇨🇭 · Peter Stoffer🇺🇸

    A key ingredient in the evaluation of hadronic light-by-light (HLbL) scattering in the anomalous magnetic moment of the muon $(g-2{)}_{\mu }$ concerns short-distance constraints (SDCs) that follow from QCD by means of the operator product expansion. Here we concentrate on the most important such constraint, in the longitudinal amplitudes, and show that it can be implemented efficiently in terms of a Regge sum over excited pseudoscalar states, constrained by phenomenological input on masses, two-photon couplings, as well as SDCs on HLbL scattering and the pseudoscalar transition form factors (TFFs). Our estimate of the effect of the longitudinal SDCs on the HLbL contribution is: $\Delta a_{\mu }^{\text{LSDC}}=13(6)\times 10^{-11}$. This is significantly smaller than previous estimates, which mostly relied on an ad-hoc modification of the pseudoscalar poles and led to up to a $40\%$ increase with respect to the nominal pseudoscalar-pole contributions, when evaluated with modern input for the relevant TFFs. We also comment on the status of the transversal SDCs and, by matching to perturbative QCD, argue that the corresponding correction will be significantly smaller than its longitudinal counterpart.

    hep-phhep-exhep-latnucl-thPRD(2020)·105 citations
16. 16*

    One-loop corrections to the $Zb\bar{b}$ vertex in models with scalar doublets and singlets

    Duarte Fontes🇵🇹 · Luis Lavoura🇵🇹 · Jorge C. Romao🇵🇹 · Joao P. Silva🇵🇹

    We study the one-loop corrections to the $Zb\bar{b}$ vertex in extensions of the Standard Model with arbitrary numbers of scalar doublets, neutral scalar singlets, and charged scalar singlets. Starting with a general parameterization of theories with neutral and singly-charged scalar particles, we derive the conditions that, in a renormalizable model, must be obeyed by the couplings in order for the divergent contributions to cancel. Then, we show that those conditions are indeed obeyed by the models that we are interested in, and we write down the full finite expression for the vertex in those models. We apply our results to some particular cases, highlighting the importance of the diagrams with neutral scalars.

    hep-phNPB(2020)·6 citations
17. 17*

    Dark matter to baryon ratio from scalar triplets decay in type-II seesaw

    Nimmala Narendra🇮🇳 · Narendra Sahu🇮🇳 · Sujay Shil🇮🇳

    We propose a minimal model for the cosmic coincidence problem ${\Omega }_{\mathrm{DM}}/{\Omega }_B\sim 5$ and neutrino mass in a type-II seesaw scenario. We extend the standard model of particle physics with a $\mathrm{SU}(2)$ singlet leptonic Dirac fermion $\chi$, which represents the candidate of dark matter (DM), and two triplet scalars ${\Delta }_{1,2}$ with hierarchical masses. In the early Universe, the CP violating out-of-equilibrium decay of lightest $\Delta$ generates a net $B-L$ asymmetry in the visible sector (comprising of SM fields), where $B$ and $L$ represents the total baryon and lepton number respectively. A part of this asymmetry gets transferred to the dark sector (comprising of DM $\chi$) through a dimension eight operator which conserves $B-L$. Above the electroweak phase transition, the $B-L$ asymmetry of the visible sector gets converted to a net $B$-asymmetry by the $B+L$ violating sphalerons, while the $B-L$ asymmetry of the dark sector remains untouched which we see today as relics of DM. We show that the observed DM abundance can be explained for a DM mass about 8 GeV. We then introduce an additional singlet scalar field $\varphi$ which mixes with the SM-Higgs to annihilate the symmetric component of the DM resonantly which requires the singlet scalar mass to be twice the DM mass, {\it i.e.} around 16 GeV, which can be searched at collider experiments. In our model, the active neutrinos also get small masses by the induced vacuum expectation value (vev) of the triplet scalars ${\Delta }_{1,2}$. In the later part of the paper we discuss all the constraints on model parameters coming from invisible Higgs decay, Higgs signal strength, DM direct detection and relic density of DM.

    hep-phEPJC(2021)·6 citations
18. 18*

    A Neutral Beam Model for High-Energy Neutrino Emission from the Blazar TXS 0506+056

    B. Theodore Zhang🇨🇳 · Maria Petropoulou🇺🇸 · Kohta Murase🇺🇸 · Foteini Oikonomou🇩🇪

    The IceCube collaboration reported a $\sim 3.5\sigma$ excess of $13\pm 5$ neutrino events in the direction of the blazar TXS 0506+56 during a $\sim$6 month period in 2014-2015, as well as the ($\sim 3\sigma$) detection of a high-energy muon neutrino during an electromagnetic flare in 2017. We explore the possibility that the 2014-2015 neutrino excess and the 2017 multi-messenger flare are both explained in a common physical framework that relies on the emergence of a relativistic neutral beam in the blazar jet due to interactions of accelerated cosmic rays (CRs) with photons. We demonstrate that the neutral beam model provides an explanation for the 2014-2015 neutrino excess without violating X-ray and $\gamma$-ray constraints, and also yields results consistent with the detection of one high-energy neutrino during the 2017 flare. If both neutrino associations with TXS 05065+056 are real, our model requires that (i) the composition of accelerated CRs is light, with a ratio of helium nuclei to protons $\gtrsim 5$, (ii) a luminous external photon field ($\sim 10^{46}$ erg s${}^{-1}$) variable (on year-long timescales) is present, and (iii) the CR injection luminosity as well as the properties of the dissipation region (i.e., Lorentz factor, magnetic field, and size) vary on year-long timescales.

    ↳ astro-ph.HEastro-ph.GAhep-phApJ(2020)·62 citations
19. 19*

    Effective Field Theory of Anisotropic Inflation and Beyond

    Jinn-Ouk Gong🇰🇷 · Toshifumi Noumi🇯🇵 · Gary Shiu🇺🇸 · Jiro Soda🇯🇵 · Kazufumi Takahashi🇯🇵 · Masahide Yamaguchi🇯🇵

    We develop an effective-field-theory (EFT) framework for inflation with various symmetry breaking pattern. As a prototype, we formulate anisotropic inflation from the perspective of EFT and construct an effective action of the Nambu-Goldstone bosons for the broken time translation and rotation symmetries. We also calculate the statistical anisotropy in the scalar two-point correlation function for concise examples of the effective action.

    ↳ hep-thastro-ph.COgr-qchep-phJCAP(2020)·13 citations
20. 20*

    $\mathcal{P},\mathcal{T}$-Violating and Magnetic Hyperfine Interactions in Atomic Thallium

    Timo Fleig🇫🇷 · Leonid V. Skripnikov🇷🇺

    We present state-of-the-art configuration interaction and coupled cluster calculations of the electron electric dipole moment, the nucleon-electron scalar-pseudoscalar, and the magnetic hyperfine interaction constants (${\alpha }_{d_e},{\alpha }_{C_S},A_{||}$, respectively) for the thallium atomic ground state ${}^2{P}_{1/2}$. Our present best values are ${\alpha }_{d_e}=-559\pm 28$, ${\alpha }_{C_S}=6.77\pm 0.34$ $[10^{-18}e$ cm$]$, and $A_{||}=21172\pm 1059$ [MHz]. These findings lead to a significant reduction of the theoretical uncertainties for $\mathcal{P},\mathcal{T}$-odd interaction constants but not to stronger constraints on the electron electric dipole moment, $d_e$, or the nucleon-electron scalar-pseudoscalar coupling constant, $C_S$.

    ↳ physics.atom-phhep-phSymmetry(2020)·17 citations
21. 21*

    Three Photon Decay of $J/\psi$ from Lattice QCD

    Yu Meng🇨🇳 · Chuan Liu🇨🇳 · Ke-Long Zhang🇨🇳

    Three photon decay rate of $J/\psi$ is studied using two $N_f=2$ twisted mass gauge ensembles with lattice spacings $a\simeq 0.085$ fm (I) and $0.067$ fm(II). Using a new method, only the correlation functions directly related to the physical decay width are computed with all polarizations of the initial and final states summed over. Our results for such rare decay on the two ensembles are: ${\mathcal{B}}_{I,II}(J/\psi \to 3\gamma )=(1.614\pm 0.016\pm 0.261)\times 10^{-5},(1.809\pm 0.051\pm 0.295)\times 10^{-5}$ where the first errors are statistical and the second are estimates from systematics. We also propose a method to analyze the Dalitz plot of the corresponding process based on the lattice data which can provide direct information for the experiments.

    ↳ hep-lathep-exhep-phPRD(2020)·9 citations
22. 22*

    Annual and Diurnal Modulations of the Angular Distribution of the 3-D WIMP Velocity Observed at an Underground Laboratory

    Chung-Lin Shan🇹🇼

    In this article, I present our (Monte Carlo) simulation results of the angular distribution of the 3-dimensional WIMP velocity, in particular, a possible "annual" modulation and the diurnal modulation proposed in literature, for different underground laboratories.

    ↳ astro-ph.HEhep-phJ.Phys.Conf.Ser.(2020)·1 citation
23. 23*

    Physics Briefing Book

    European Strategy for Particle Physics Preparatory Group

    The European Particle Physics Strategy Update (EPPSU) process takes a bottom-up approach, whereby the community is first invited to submit proposals (also called inputs) for projects that it would like to see realised in the near-term, mid-term and longer-term future. National inputs as well as inputs from National Laboratories are also an important element of the process. All these inputs are then reviewed by the Physics Preparatory Group (PPG), whose role is to organize a Symposium around the submitted ideas and to prepare a community discussion on the importance and merits of the various proposals. The results of these discussions are then concisely summarised in this Briefing Book, prepared by the Conveners, assisted by Scientific Secretaries, and with further contributions provided by the Contributors listed on the title page. This constitutes the basis for the considerations of the European Strategy Group (ESG), consisting of scientific delegates from CERN Member States, Associate Member States, directors of major European laboratories, representatives of various European organizations as well as invitees from outside the European Community. The ESG has the mission to formulate the European Strategy Update for the consideration and approval of the CERN Council.

    ↳ hep-exhep-ph397 citations
24. 24*

    Grand Unified Neutrino Spectrum at Earth: Sources and Spectral Components

    Edoardo Vitagliano🇺🇸 · Irene Tamborra🇩🇰 · Georg Raffelt🇩🇪

    We briefly review the dominant neutrino fluxes at Earth from different sources and present the Grand Unified Neutrino Spectrum ranging from meV to PeV energies. For each energy band and source, we discuss both theoretical expectations and experimental data. This compact review should be useful as a brief reference to those interested in neutrino astronomy, fundamental particle physics, dark-matter detection, high-energy astrophysics, geophysics, and other related topics.

    ↳ astro-ph.HEhep-exhep-phnucl-thRMP(2020)·280 citations
25. 25*

    The standard model, the Pati-Salam model, and "Jordan geometry"

    Latham Boyle🇨🇦 · Shane Farnsworth🇩🇪

    We argue that the ordinary commutative-and-associative algebra of spacetime coordinates (familiar from general relativity) should perhaps be replaced, not by a noncommutative algebra (as in noncommutative geometry), but rather by a Jordan algebra (leading to a framework which we term "Jordan geometry"). We present the Jordan algebra (and representation) that most nearly describes the standard model of particle physics, and we explain that it actually describes a certain (phenomenologically viable) extension of the standard model: by three right-handed (sterile) neutrinos, a complex scalar field $\phi$, and a $U(1{)}_{B-L}$ gauge boson which is Higgsed by $\phi$. We then note a natural extension of this construction, which describes the $SU(4)\times SU(2{)}_L\times SU(2{)}_R$ Pati-Salam model. Finally, we discuss a simple and natural Jordan generalization of the exterior algebra of differential forms.

    ↳ hep-thhep-phmath-phmath.MPNew J.Phys.(2020)·34 citations
26. 26*

    Is Hyperon Polarization in Relativistic Heavy Ion Collisions Connected to Axial U(1) Symmetry Breaking at High Temperature?

    Joseph I. Kapusta🇺🇸 · Ermal Rrapaj🇺🇸 · Serge Rudaz🇺🇸

    Experiments at the Relativistic Heavy Ion Collider (RHIC) have measured the net polarization of $\Lambda$ and $\bar{\Lambda }$ hyperons and attributed it to a coupling between their spin and the vorticity of the fluid created in heavy ion collisions, but how the spin comes to equilibrium with vorticity is an open problem. Recently we found that vorticity fluctuations and helicity flip of strange quarks in quark-gluon plasma through perturbative QCD processes resulted in equilibration times far too long to be relevant. Here we consider the Nambu--Jona-Lasinio model with the inclusion of the six-quark Kobayashi--Maskawa--'t Hooft interaction which breaks axial U(1). Using instanton inspired models for the temperature dependence of the axial symmetry breaking, we find that constituent strange quarks can reach spin equilibrium at temperatures below about 170 MeV, just before they hadronize to form hyperons.

    ↳ nucl-thhep-phPRC(2020)·34 citations
27. 27*

    The Once and Present Standard Model of Elementary Particle Physics

    James D. Wells🇺🇸

    There are many theories that have resided these last fifty years within the hazy mist we have been calling the Standard Model (SM) of elementary particles. An attempt is made here to construct a coherent description of the SM today, because only precisely articulated theories can be targeted for annihilation, corroboration, and alteration. To this end it is useful to categorize the facts, mysteries and myths that together build a single conception of the SM. For example, it is argued that constructing a myth for how neutrinos obtain mass is useful for progress. We also advocate for interpreting the cosmological constant, dark matter, baryogenesis, and inflation as four "mysteries of the cosmos" that are indeterminate regarding new particles or interactions, despite a multitude of available particle explanations. Some history of the ever-changing SM is also presented to remind us that today's SM is not our parents' SM, nor will it likely be our children's SM.

    ↳ physics.hist-phhep-ph7 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.