Tue·Jan 15, 2019Tuesday·January 15, 2019

1. 01*

   GW170817 implications on the frequency and damping time of f-mode oscillations of neutron stars

   De-Hua Wen🇨🇳 · Bao-An Li🇺🇸 · Hou-Yuan Chen🇨🇳 · Nai-Bo Zhang🇨🇳

   Within a minimum model for neutron stars consisting of nucleons, electrons and muons at $\beta$-equilibrium using about a dozen Equation of States (EOSs) from microscopic nuclear many-body theories and 40,000 EOSs randomly generated using an explicitly isospin-dependent parametric EOS model for high-density neutron-rich nucleonic matter within its currently known uncertainty range, we study correlations among the f-mode frequency, its damping time and the tidal deformability as well as the compactness of neutron stars. Except for quark stars, both the f-mode frequency and damping time of canonical neutron stars are found to scale with the tidal deformability independent of the EOSs used. Applying the constraint on the tidal deformability of canonical neutron stars ${\Lambda }_{1.4}=190_{-120}^{+390}$ extracted by the LIGO+VIRGO Collaborations from their improved analyses of the GW170817 event, the f-mode frequency and its damping time of canonical neutron stars are limited to 1.67 kHz - 2.18 kHz and 0.155 s - 0.255 s, respectively, providing a useful guidance for the ongoing search for gravitational waves from the f-mode oscillations of isolated neutron stars. Moreover, assuming either or both the f-mode frequency and its damping time will be measured precisely in future observations with advanced gravitational wave detectors, we discuss how information about the mass and/or radius as well as the still rather elusive nuclear symmetry energies at supra-saturation densities may be extracted.

   ↳ gr-qcastro-ph.HEastro-ph.SRnucl-ex+1PRC(2019)·69 citations
2. 02*

   Precision Analysis of the ${}^{136}$Xe Two-Neutrino $\beta \beta$ Spectrum in KamLAND-Zen and Its Impact on the Quenching of Nuclear Matrix Elements

   KamLAND-Zen Collaboration

   We present a precision analysis of the ${}^{136}$Xe two-neutrino $\beta \beta$ electron spectrum above 0.8 MeV, based on high-statistics data obtained with the KamLAND-Zen experiment. An improved formalism for the two-neutrino $\beta \beta$ rate allows us to measure the ratio of the leading and subleading $2\nu \beta \beta$ nuclear matrix elements (NMEs), ${\xi }_{31}^{2\nu }=-0.26_{-0.25}^{+0.31}$. Theoretical predictions from the nuclear shell model and the majority of the quasiparticle random-phase approximation (QRPA) calculations are consistent with the experimental limit. However, part of the ${\xi }_{31}^{2\nu }$ range allowed by the QRPA is excluded by the present measurement at the 90% confidence level. Our analysis reveals that predicted ${\xi }_{31}^{2\nu }$ values are sensitive to the quenching of NMEs and the competing contributions from low- and high-energy states in the intermediate nucleus. Since these aspects are also at play in neutrinoless $\beta \beta$ decay, ${\xi }_{31}^{2\nu }$ provides new insights towards reliable neutrinoless $\beta \beta$ NMEs.

   ↳ hep-exnucl-exnucl-thPRL(2019)·97 citations
3. 03*

   Neutron radii and neutron skin of neutron-rich nuclei deduced from proton-nucleus total reaction cross sections

   I. A. M. Abdul-Magead🇷🇺 · Eman Hamza · Badawy Abu-Ibrahim

   A new method is proposed to deduce the neutron radii of neutron-rich nuclei. This method requires measuring the reaction cross sections of both the neutron-rich nucleus and its stable isotope at the same energy on a proton target. Using this method and the available experimental data of ${}^{12,22}$C + $p$ and ${}^{9,14}$Be + $p$ at 40$A$ MeV, the neutron radii of ${}^{22}$C and ${}^{14}$Be have been deduced for the first time.

   ↳ nucl-thnucl-exJ.Phys.G(2020)·2 citations
4. 04*

   First 4D lattice calculation of transport coefficient $\hat{q}$ for pure gluon plasma

   Amit Kumar (Wayne State University USA)🇺🇸 · Abhijit Majumder (Wayne State University USA)🇺🇸 · Chiho Nonaka (Nagoya University Japan)🇯🇵

   The transport coefficient $\hat{q}$ plays a pivotal role in describing the phenomenon of jet quenching in the quark-gluon plasma (QGP) produced in ultra-relativistic nucleus-nucleus collisions. It is challenging to compute this coefficient from first principles due to its non-perturbative nature. In this article, we present an $ab$-$initio$ formulation of $\hat{q}$ based on the standard techniques of perturbative quantum chromodynamics (pQCD) and lattice gauge theory. We construct $\hat{q}$ by considering a leading order (LO) process where a hard parton produced from the hard scattering undergoes transverse broadening due to scatterings with the thermal medium. We do an analytic continuation to the Euclidean region and use the dispersion relation to express $\hat{q}$ in terms of series of local Field-Strength-Field-Strength (FF) operators. Each term in the series is suppressed by the hard scale $q^{-}$. Finally, we compute the local operators on the quenched SU(3) lattice and present our estimates for $\hat{q}$.

   ↳ nucl-thhep-latnucl-exPoS(2019)·5 citations
5. 05*

   Impact of magnetic-field fluctuations on measurements of the chiral magnetic effect in collisions of isobaric nuclei

   Xin-Li Zhao🇨🇳 · Guo-Liang Ma🇨🇳 · Yu-Gang Ma🇨🇳

   We investigate the properties of electromagnetic fields in isobaric ${}_{44}^{96}\text{Ru}+{}_{44}^{96}\text{Ru}$ and ${}_{40}^{96}\text{Zr}+{}_{40}^{96}\text{Zr}$ collisions at $\sqrt{s}$ = 200 GeV by using a multiphase transport model, with special emphasis on the correlation between magnetic field direction and participant plane angle ${\Psi }_2$ (or spectator plane angle ${\Psi }_2^{\mathrm{SP}}$), i.e. $⟨\cos 2({\Psi }_B-{\Psi }_2)⟩$ [or $⟨\cos 2({\Psi }_B-{\Psi }_2^{\mathrm{SP}})⟩$]. We confirm that the magnetic fields of ${}_{44}^{96}\text{Ru}+{}_{44}^{96}\text{Ru}$ collisions are stronger than those of ${}_{40}^{96}\text{Zr}+{}_{40}^{96}\text{Zr}$ collisions due to their larger proton fraction. We find that the deformation of nuclei has a non-negligible effect on $⟨\cos 2({\Psi }_B-{\Psi }_2)⟩$ especially in peripheral events. Because the magnetic-field direction is more strongly correlated with ${\Psi }_2^{\mathrm{SP}}$ than with ${\Psi }_2$, the relative difference of the chiral magnetic effect observable with respect to ${\Psi }_2^{\mathrm{SP}}$ is expected to be able to reflect much cleaner information about the chiral magnetic effect with less influences of deformation.

   ↳ hep-phnucl-exnucl-thPRC(2019)·40 citations
6. 06*

   Novel mechanism for electric quadrupole moment generation in relativistic heavy-ion collisions

   Xin-Li Zhao🇨🇳 · Guo-Liang Ma🇨🇳 · Yu-Gang Ma🇨🇳

   We present the spatial distributions of electromagnetic fields ($\mathbf{E}$ and $\mathbf{B}$) and electromagnetic anomaly $\mathbf{E}\cdot \mathbf{B}$ in Au+Au collisions at the RHIC energy $\sqrt{s}$=200 GeV based on a multi-phase transport model. A dipolar distribution of $\mathbf{E}\cdot \mathbf{B}$ is observed in non-central collisions. We find that the coupling of the $\mathbf{E}\cdot \mathbf{B}$ dipole and magnetic field $\mathbf{B}$ can induce an electric quadrupole moment which can further lead to the difference in elliptic flows between positive charged particles and negative charged particles through final interactions. The centrality dependence of the density of $\mathbf{E}\cdot \mathbf{B}$ is similar to the trend of the slope parameter $r$ measured from the difference in elliptic flows between positive pions and negative pions by the STAR collaboration. Therefore, the novel mechanism for electric quadrupole moment generation can offer a new interpretation of the observed charge-dependent elliptic flow of pions, but without the formation of chiral magnetic wave.

   ↳ hep-phnucl-exnucl-thPLB(2019)·30 citations
7. 07*

   Jet substructure measurements in pp collisions at $\sqrt{s}$ = 13 TeV with ALICE

   Markus Fasel (for the ALICE Collaboration)🇺🇸

   We present a variety of jet substructure measurements performed in pp collisions at $\sqrt{s}$ = 13 TeV with the focus on the groomed jet momentum fraction $z_{\mathrm{g}}$ in a wide range of $p_{\mathrm{T}}$ between 20 and 200 GeV/$c$ and jet resolution $0.2<R<0.5$. Thanks to the capabilities of the ALICE apparatus jet substructure measurement are possible with an infrared constituent cutoff at 0.3 GeV. Furthermore, the angular resolution of the ALICE detectors allows the measurement of jet substructure observables with a high precision. The measurements are compared to pQCD calculations and MC generators. Furthermore, the measurement of track-based jets at the same centre-of-mass energy and its dependence on the event activity are presented for different jet resolutions.

   ↳ hep-exnucl-exPoS(2018)·0 citations
8. 08*

   Multi-particle and charge-dependent azimuthal correlations in heavy-ion collisions at the Relativistic Heavy-Ion Collider

   Bjoern Schenke🇺🇸 · Chun Shen🇺🇸 · Prithwish Tribedy🇺🇸

   We study multi-particle azimuthal correlations in relativistic heavy-ion collisions at a center of mass energy of 200 GeV. We use the IP-Glasma model to initialize the viscous hydrodynamic simulation MUSIC and employ the UrQMD transport model for the low temperature region of the collisions. In addition, we study effects of local charge and global momentum conservation among the sampled particles. With the exception of the lowest order three particle correlator $C_{112}$, our framework provides a good description of the existing charge inclusive azimuthal correlation data for Au+Au and U+U collisions at RHIC. We also present results for charge dependent two and three particle correlators in Au+Au and U+U collisions, and make predictions for isobar (Ru+Ru & Zr+Zr) collisions to provide a much needed baseline for the search for the Chiral Magnetic Effect at RHIC.

   ↳ nucl-thhep-phnucl-exPRC(2019)·78 citations
9. 09*

   Physics Beyond Colliders: QCD Working Group Report

   A. Dainese🇮🇹 · M. Diehl🇩🇪 · P. Di Nezza🇮🇹 · J. Friedrich🇩🇪 · M. Gaździcki🇩🇪 · G. Graziani🇮🇹 · C. Hadjidakis🇫🇷 · J. Jäckel🇩🇪 · J. P. Lansberg🇫🇷 · A. Magnon🇨🇭 · G. Mallot🇨🇭 · F. Martinez Vidal🇪🇸 and 11 other authors

   This report summarises the main findings of the QCD Working Group in the CERN Physics Beyond Colliders Study.

   ↳ hep-exhep-phnucl-exnucl-th26 citations
10. 10*

    Thermonuclear fusion rates for tritium + deuterium using Bayesian methods

    Rafael S. de Souza🇺🇸 · S. Reece Boston🇺🇸 · Alain Coc🇫🇷 · Christian Iliadis🇺🇸

    The ${}^3$H(d,n)${}^4$He reaction has a large low-energy cross section and will likely be utilized in future commercial fusion reactors. This reaction also takes place during big bang nucleosynthesis. Studies of both scenarios require accurate and precise fusion rates. To this end, we implement a one-level, two-channel R-matrix approximation into a Bayesian model. Our main goals are to predict reliable astrophysical S-factors and to estimate R-matrix parameters using the Bayesian approach. All relevant parameters are sampled in our study, including the channel radii, boundary condition parameters, and data set normalization factors. In addition, we take uncertainties in both measured bombarding energies and S-factors rigorously into account. Thermonuclear rates and reactivities of the ${}^3$H(d,n)${}^4$He reaction are derived by numerically integrating the Bayesian S-factor samples. The present reaction rate uncertainties at temperatures between $1.0$ MK and $1.0$ GK are in the range of 0.2% to 0.6%. Our reaction rates differ from previous results by 2.9% near 1.0 GK. Our reactivities are smaller than previous results, with a maximum deviation of 2.9% near a thermal energy of $4$ keV. The present rate or reactivity uncertainties are more reliable compared to previous studies that did not include the channel radii, boundary condition parameters, and data set normalization factors in the fitting. Finally, we investigate previous claims of electron screening effects in the published ${}^3$H(d,n)${}^4$He data. No such effects are evident and only an upper limit for the electron screening potential can be obtained.

    ↳ nucl-thastro-ph.IMnucl-exphysics.data-anPRC(2019)·27 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.