Thu·Jan 21, 2021Thursday·January 21, 2021

1. 01*

   Investigation of $P_{cs}(4459{)}^0$ pentaquark via its strong decay to $\Lambda J/\Psi$

   K. Azizi🇮🇷 · Y. Sarac🇹🇷 · H. Sundu🇹🇷

   Recently the observation of a new pentaquark state, the hidden-charmed strange $P_{cs}(4459{)}^0$, was reported by the LHCb Collaboration. The spin-parity quantum numbers of this state were not determined as a result of insufficient statistics. To shed light on its quantum numbers, we investigate its decay, $P_{cs}(4459{)}^0\to J/\psi \Lambda$, the mode that this state has been observed, within the QCD sum rule framework. We obtain the width of this decay assigning the spin-parity quantum numbers of $P_{cs}(4459{)}^0$ state as $J^P={\frac{1}{2}}^{-}$ and its substructure as diquark-diquark-antiquark. To this end, we first calculate the strong coupling constants defining the considered decay and then use them in the width calculations. The obtained width is consistent with the experimental observation, confirming the quantum numbers $J^P={\frac{1}{2}}^{-}$ and compact pentaquark nature for $P_{cs}(4459{)}^0$ state.

   hep-phhep-exhep-latPRD(2021)·49 citations
2. 02*

   An evidence of triple kinetic freezeout scenario observed in all centrality intervals in Cu-Cu, Au-Au and Pb-Pb collisions at high energies

   M. Waqas🇨🇳 · G. X. Peng🇨🇳 · Fu-Hu Liu🇨🇳

   Transverse momentum spectra of ${\pi }^{+}$, $K^{+}$, $p$, $K_s^0$, $\Lambda$, $\Xi$ or ${\bar{\Xi }}^{+}$ and $\Omega$ or ${\bar{\Omega }}^{+}$ or $\Omega +\bar{\Omega }$ in Copper-Copper (Cu-Cu), Gold-Gold (Au-Au) and Lead-Lead (Pb-Pb) collisions at 200 GeV, 62.4 GeV and 2.76 TeV respectively, are analyzed in different centrality bins by the blast wave model with Tsallis statistics. The model results are approximately in agreement with the experimental data measured by BRAHMS, STAR and ALICE Collaborations in special transverse momentum ranges. Kinetic freeze out temperature, transverse flow velocity and kinetic freezeout volume are extracted from the transverse momentum spectra of the particles. It is observed that ${\bar{\Xi }}^{+}$ and $\Omega$ or ${\bar{\Omega }}^{+}$ or $\Omega +\bar{\Omega }$ have larger kinetic freezeout temperature followed by $K^{+}$, $K_s^0$ and $\Lambda$ than ${\pi }^{+}$ and $p$ due to smaller reaction cross-sections of multi-strange and strange particles than non-strange particles. The present work reveals the scenario of triple kinetic freezeout in collisions at BRAHMS, STAR and ALICE Collaborations, however the transverse flow velocity and kinetic freezeout volume are mass dependent and they decrease with the increasing rest mass of the particle. In addition, the kinetic freezeout temperature, transverse flow velocity and kinetic freezeout volume are decreasing from central to peripheral collisions while the parameter q increase from central to peripheral collisions, indicating the approach of quick equilibrium in the central collisions. Besides, the kinetic freezeout temperature and kinetic freezeout volume are observed to be larger in larger collision system which shows its dependence on the size of the interacting system, while transverse flow velocity increase with increasing energy.

   hep-phJ.Phys.G(2021)·44 citations
3. 03*

   The electric dipole moment of the tau lepton revisited

   Werner Bernreuther🇩🇪 · Long Chen🇩🇪 · Otto Nachtmann🇩🇪

   We reconsider the issue of the search for a nonzero electric dipole form factor (EDM) $d_{\tau }(s)$ using optimal observables in ${\tau }^{+}{\tau }^{-}$ production by $e^{+}{e}^{-}$ collisions in the center-of-mass energy range from the $\tau$-pair threshold to about $\sqrt{s}\sim 15$ GeV. We discuss the general formalism of optimal observables and apply it to two $CP$-odd observables that are sensitive to the real and imaginary part of $d_{\tau }(s)$, respectively. We compute the expectation values and covariances of these optimal $CP$ observables for $\tau$-pair production at $\sqrt{s}=10.58$ GeV with subsequent decays of ${\tau }^{\pm }$ into major leptonic or semihadronic modes. For the $\tau$ decays to two pions and three charged pions we take the full kinematic information of the hadronic system into account. Assuming that the Belle II experiment at the KEKB accelerator will eventually analyze data corresponding to an integrated luminosity of 50 ab${}^{-1}$ and applying acceptance cuts on the final-state pions we find that 1~s.d. sensitivities $\delta \mathrm{Re}{d}_{\tau }=6.8\times 10^{-20}$ e cm and $\delta Im{d}_{\tau }=4.0\times 10^{-20}$ e cm can be obtained with events where both $\tau$'s decay semihadronically. In the ideal case where no cuts on the final-state particles are applied we find with 50 ab${}^{-1}$ at $\sqrt{s}=10.58$ GeV corresponding to $4.5\times 10^{10}$ ${\tau }^{+}{\tau }^{-}$ events the 1 s.d. sensitivities $\delta \mathrm{Re}{d}_{\tau }=5.8\times 10^{-20}$ e cm and $\delta Im{d}_{\tau }=3.2\times 10^{-20}$ e cm, again for events where both $\tau$ leptons decay semihadronically. Furthermore, we analyze the potential magnitude of the $\tau$ EDM form factor in the type-II two-Higgs doublet extension and in two scalar leptoquark extensions of the Standard Model.

   hep-phhep-exPRD(2021)·35 citations
4. 04*

   Constraining CPT violation with Hyper-Kamiokande and ESSnuSB

   Rudra Majhi🇮🇳 · Dinesh Kumar Singha🇮🇳 · K. N. Deepthi🇮🇳 · Rukmani Mohanta🇮🇳

   CPT invariance is one of the most fundamental symmetries in nature and it plays a major role in the formulation of Quantum Field Theory. Although no definitive signal of CPT violation has been observed so far, there are many reasons to carefully investigate various low-energy phenomena that can provide better probes to test CPT symmetry. In this context, neutrino experiments are expected to provide more stringent bounds on CPT invariance violation when compared to the existing bounds from the Kaon system. In this work, we investigate the sensitivity of the upcoming long-baseline experiments: Hyper Kamiokande (T2HK, T2HKK), ESSnuSB and DUNE to constrain the CPT violating parameters $\Delta ({\delta }_{CP})$, $\Delta (m_{31}^2)$ and $\Delta ({\sin }^2{\theta }_{23})$, which characterize the difference between neutrino and antineutrino oscillation parameters. Further, we analyse neutrino and antineutrino data independently and constrain the oscillation parameters governing them by considering the combination of these experiments (DUNE+T2HKK and DUNE+ESSnuSB). In addition, assuming CPT symmetry is violated in nature, we study the individual ability of the aforementioned experiments to establish CPT violation. We found that the experiments Hyper-K (T2HK, T2HKK) and ESSnuSB, along with DUNE, will be able to establish CPT violation in their proposed run-times.

   hep-phPRD(2021)·10 citations
5. 05*

   Renormalization group improved pressure for hot and dense quark matter

   Jean-Loïc Kneur🇫🇷 · Marcus Benghi Pinto🇧🇷 · Tulio E. Restrepo🇧🇷

   We apply the renormalization group optimized perturbation theory (RGOPT) to evaluate the quark contribution to the QCD pressure at finite temperatures and baryonic densities, at next-to-leading order (NLO). Our results are compared to NLO and state-of-the-art higher orders of standard perturbative QCD (pQCD) and hard thermal loop perturbation theory (HTLpt). The RGOPT resummation provides a nonperturbative approximation, exhibiting a drastically better remnant renormalization scale dependence than pQCD, thanks to built-in renormalization group invariance consistency. At NLO, upon simply adding to the RGOPT-resummed quark contributions the purely perturbative NLO glue contribution, our results show a remarkable agreement with ab initio lattice simulation data for temperatures $0.25\lesssim T\lesssim 1\mathrm{GeV}$, with a remnant scale dependence drastically reduced as compared to HTLpt.

   hep-phhep-latnucl-thPRD(2021)·11 citations
6. 06*

   Theory Overview of Heavy Exotic Spectroscopy

   Ciaran Hughes🇺🇸

   This proceeding broadly overviews the current landscape of heavy exotic spectroscopy. Such work includes the composition of certain X, Y , and Z states, and proceeds to discuss tetraquarks made exclusively of four quarks.

   hep-phhep-exhep-latPoS(2021)·5 citations
7. 07*

   Search for a heavy neutral Higgs boson in a left-right model with an inverse seesaw mechanism at the LHC

   M. Ashry🇪🇬 · K. Ezzat🇪🇬 · S. Khalil🇪🇬

   We develop a low scale left-right symmetric model based on $SU(3{)}_C\times SU(2{)}_L\times SU(2{)}_R\times U(1{)}_{B-L}\times Z_2$ with a simplified Higgs sector consisting of only one bidoublet and one $SU(2{)}_R$ doublet. In this model, the tiny values of light neutrino masses are generated through an inverse-seesaw mechanism. We emphasize that in this setup, the tree-level flavor changing neutral current can be strongly suppressed, consistent with the current experimental constraints. We show that the lightest $CP$-even Higgs boson, which is like the standard model Higgs boson, and the next lightest Higgs boson, $h^{\prime }$, are generated from the neutral components of the bidoublet. We show that the mass of the next lightest Higgs boson can be of an order a few hundred~\text{GeVs}. We analyze the detection of $h^{\prime }$ at the Large Hadron Collider (LHC) for a center-of-mass energy $\sqrt{s}=14\text{TeV}$ and integrated luminosity $L_{\text{int}}=300{\text{fb}}^{-1}$ via di-Higgs channel: $h^{\prime }\to hh\to b\bar{b}\gamma \gamma$ and also in the $ZZ$ channel: $h^{\prime }\to ZZ\to 4\ell (\ell =e,\mu )$ at an integrated luminosity $L_{\text{int}}=3000{\text{fb}}^{-1}$. We consider three benchmark points for this analysis with $m_{h^{\prime }}=250\text{GeV},400\text{GeV}$, and $600\text{GeV}$. We show that promising signals with good statistical significances can be obtained in di-Higgs channel, with $2\gamma +2b$-jets final states.

   hep-phPRD(2021)·12 citations
8. 08*

   Determining Dark Matter-Electron Scattering Rates from the Dielectric Function

   Yonit Hochberg🇮🇱 · Yonatan Kahn🇺🇸 · Noah Kurinsky🇺🇸 · Benjamin V. Lehmann🇺🇸 · To Chin Yu🇺🇸 · Karl K. Berggren🇺🇸

   We show that the rate for dark matter-electron scattering in an arbitrary material is determined by an experimentally measurable quantity, the complex dielectric function, for any dark matter interaction that couples to electron density. This formulation automatically includes many-body effects, eliminates all systematic theoretical uncertainties on the electronic wavefunctions, and allows a direct calibration of the spectrum by electromagnetic probes such as infrared spectroscopy, X-ray scattering, and electron energy-loss spectroscopy (EELS). Our formalism applies for several common benchmark models, including spin-independent interactions through scalar and vector mediators of arbitrary mass. We discuss the consequences for standard semiconductor and superconductor targets, and find that the true reach of superconductor detectors for light mediators exceeds previous estimates by several orders of magnitude, with further enhancements possible due to the low-energy tail of the plasmon. Using a heavy-fermion superconductor as an example, we show how our formulation allows a rapid and systematic investigation of novel electron scattering targets.

   hep-phcond-mat.mtrl-scihep-exPRL(2021)·121 citations
9. 09*

   RGBeta: A Mathematica Package for the Evaluation of Renormalization Group $\beta$-Functions

   Anders Eller Thomsen🇨🇭

   In completely generic four-dimensional gauge-Yukawa theories, the renormalization group $\beta$-functions are known to the 3-2-2 loop order in gauge, Yukawa, and quartic couplings, respectively. It does, however, remain difficult to apply these results to specific models without the use of dedicated computer tools. We describe a procedure for extracting $\beta$-functions using the general results and introduce RGBeta, a dedicated Mathematica package for extracting the $\overline{\text{MS}}$ $\beta$-functions in broad classes of models. The package and example notebooks are available from the GitHub repository at https://github.com/aethomsen/RGBeta .

   hep-phEPJC(2021)·69 citations
10. 10*

    Dark matter-electron scattering in dielectrics

    Simon Knapen🇨🇭 · Jonathan Kozaczuk🇺🇸 · Tongyan Lin🇺🇸

    A number of direct detection experiments are searching for electron excitations created by scattering of sub-GeV dark matter. We present an alternate formulation of dark matter-electron scattering in terms of the dielectric response of a material. For dark matter which couples to electrons, this approach automatically accounts for in-medium screening effects, which were not included in previous rate calculations for semiconductor targets. We show that the screening effects appear for both scalar and vector mediators. The result is a non-negligible reduction of reach for direct detection experiments which use dielectric materials as targets. We also explore different determinations of the dielectric response, including first-principles density functional theory (DFT) calculations and a data-driven analytic approximation using a Mermin oscillator model.

    hep-phPRD(2021)·122 citations
11. 11*

    NANOGrav Signal from First-Order Confinement/Deconfinement Phase Transition in Different QCD Matters

    Shou-Long Li🇨🇳 · Lijing Shao🇨🇳 · Puxun Wu🇨🇳 · Hongwei Yu🇨🇳

    Recently, an indicative evidence of a stochastic process, reported by the NANOGrav Collaboration based on the analysis of 12.5-year pulsar timing array data which might be interpreted as a potential stochastic gravitational wave signal, has aroused keen interest of theorists. The first-order color charge confinement phase transition at the QCD scale could be one of the cosmological sources for the NANOGrav signal. If the phase transition is flavor dependent and happens sequentially, it is important to find that what kind of QCD matter in which the first-order confinement/deconfinement phase transition happens is more likely to be the potential source of the NANOGrav signal during the evolution of the universe. In this paper, we would like to illustrate that the NANOGrav signal could be generated from confinement/deconfinement transition in either heavy static quarks with a zero baryon chemical potential, or quarks with a finite baryon chemical potential. In contrast, the gluon confinement could not possibly be the source for the NANOGrav signal according to the current observation. Future observation will help to distinguish between different scenarios.

    ↳ astro-ph.COgr-qchep-phhep-thPRD(2021)·53 citations
12. 12*

    Bottomonium precision tests from full lattice QCD: hyperfine splitting, ${\rm Y}$ leptonic width and $b$ quark contribution to $e^{+}{e}^{-}\to$ hadrons

    D. Hatton🇬🇧 · C. T. H. Davies🇬🇧 · J. Koponen🇩🇪 · G. P. Lepage🇺🇸 · A. T. Lytle🇺🇸

    We calculate the mass difference between the ${\rm Y}$ and ${\eta }_b$ and the ${\rm Y}$ leptonic width from lattice QCD using the Highly Improved Staggered Quark formalism for the $b$ quark and including $u$, $d$, $s$ and $c$ quarks in the sea. We have results for lattices with lattice spacing as low as 0.03 fm and multiple heavy quark masses, enabling us to map out the heavy quark mass dependence and determine values at the $b$ quark mass. Our results are: $M_{{\rm Y}}-M_{{\eta }_b}=57.5(2.3)(1.0)\mathrm{MeV}$ (where the second uncertainty comes from neglect of quark-line disconnected correlation functions) and decay constants, $f_{{\eta }_b}=724(12)$ MeV and $f_{{\rm Y}}=677.2(9.7)$ MeV, giving $\Gamma ({\rm Y}\to e^{+}{e}^{-})=1.292(37)(3)\mathrm{keV}$. The hyperfine splitting and leptonic width are both in good agreement with experiment, and provide the most accurate lattice QCD results to date for these quantities by some margin. At the same time results for the time moments of the vector-vector correlation function can be compared to values for the $b$ quark contribution to $\sigma (e^{+}{e}^{-}\to \mathrm{hadrons})$ determined from experiment. Moments 4--10 provide a 2\% test of QCD and yield a $b$ quark contribution to the anomalous magnetic moment of the muon of 0.300(15)$\times 10^{-10}$. Our results, covering a range of heavy quark masses, may also be useful to constrain QCD-like composite theories for beyond the Standard Model physics.

    ↳ hep-lathep-phPRD(2021)·39 citations
13. 13*

    Core Fragmentation in Simplest Superfluid Dark Matter Scenario

    Lasha Berezhiani🇩🇪 · Giordano Cintia🇩🇪 · Max Warkentin🇩🇪

    We study the structure of galactic halos within a scalar dark matter model, endowed with a repulsive quartic self-interaction, capable of undergoing the superfluid phase transition in high-density regions. We demonstrate that the thermalized cores are prone to fragmentation into superfluid droplets due to the Jeans instability. Furthermore, since cores of astrophysical size may be generated only when most of the particles comprising the halo reside in a highly degenerate phase-space, the well-known bound on the dark matter self-interaction cross section inferred from the collision of clusters needs to be revised, accounting for the enhancement of the interaction rate due to degeneracy. As a result, generation of kpc-size superfluid solitons, within the parameter subspace consistent with the Bullet Cluster bound, requires dark matter particles to be ultra-light.

    ↳ astro-ph.COastro-ph.GAhep-phPLB(2021)·20 citations
14. 14*

    Extensive Studies of the Neutron Star Equation of State from the Deep Learning Inference with the Observational Data Augmentation

    Yuki Fujimoto🇯🇵 · Kenji Fukushima🇯🇵 · Koichi Murase🇨🇳

    We discuss deep learning inference for the neutron star equation of state (EoS) using the real observational data of the mass and the radius. We make a quantitative comparison between the conventional polynomial regression and the neural network approach for the EoS parametrization. For our deep learning method to incorporate uncertainties in observation, we augment the training data with noise fluctuations corresponding to observational uncertainties. Deduced EoSs can accommodate a weak first-order phase transition, and we make a histogram for likely first-order regions. We also find that our observational data augmentation has a byproduct to tame the overfitting behavior. To check the performance improved by the data augmentation, we set up a toy model as the simplest inference problem to recover a double-peaked function and monitor the validation loss. We conclude that the data augmentation could be a useful technique to evade the overfitting without tuning the neural network architecture such as inserting the dropout.

    ↳ nucl-thastro-ph.HEastro-ph.IMcs.LG+1JHEP(2021)·76 citations
15. 15*

    Efficient highly-subsonic turbulent dynamo and growth of primordial magnetic fields

    Radhika Achikanath Chirakkara🇮🇳 · Christoph Federrath🇦🇺 · Pranjal Trivedi🇩🇪 · Robi Banerjee🇩🇪

    We present the first study on the amplification of magnetic fields by the turbulent dynamo in the highly subsonic regime, with Mach numbers ranging from $10^{-3}$ to $0.4$. We find that for the lower Mach numbers the saturation efficiency of the dynamo, $(E_{\mathrm{mag}}/E_{\mathrm{kin}}{)}_{\mathrm{sat}}$, increases as the Mach number decreases. Even in the case when injection of energy is purely through longitudinal forcing modes, $(E_{\mathrm{mag}}/E_{\mathrm{kin}}{)}_{\mathrm{sat}}$ $\gtrsim 10^{-2}$ at a Mach number of $10^{-3}$. We apply our results to magnetic field amplification in the early Universe and predict that a turbulent dynamo can amplify primordial magnetic fields to $\gtrsim$ $10^{-16}$ Gauss on scales up to 0.1 pc and $\gtrsim$ $10^{-13}$ Gauss on scales up to 100 pc. This produces fields compatible with lower limits of the intergalactic magnetic field inferred from blazar $\gamma$-ray observations.

    ↳ astro-ph.HEastro-ph.COhep-phphysics.flu-dynPRL(2021)·20 citations
16. 16*

    MultivariateApart: Generalized Partial Fractions

    Matthias Heller🇩🇪 · Andreas von Manteuffel🇺🇸

    We present a package to perform partial fraction decompositions of multivariate rational functions. The algorithm allows to systematically avoid spurious denominator factors and is capable of producing unique results also when being applied to terms of a sum separately. The package is designed to work in Mathematica, but also provides interfaces to the Form and Singular computer algebra systems.

    ↳ cs.SChep-phhep-thComput.Phys.Commun.(2022)·123 citations
17. 17*

    The Dark Matter Enigma

    Jean-Pierre Luminet (Aix-Marseille Université, CNRS, Laboratoire d'Astrophysique de Marseille, France)🇫🇷

    In this pedestrian approach I give my personal point of view on the various problems posed by dark matter in the universe. After a brief historical overview I discuss the various solutions stemming from high energy particle physics, and the current status of experimental research on candidate particles (WIMPS). In the absence of direct evidence, the theories can still be evaluated by comparing their implications for the formation of galaxies, clusters and superclusters of galaxies against astronomical observations. I conclude briefly with the attempts to circumvent the dark matter problem by modifying the laws of gravity.

    ↳ physics.pop-phastro-ph.COhep-phInference - The International Review of S…·1 citation

* 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.