Thu·Jun 27, 2019Thursday·June 27, 2019

1. 01*

   Statistically significant observation of and cross sections for a new nuclear reaction channel on 197Au with bound dineutron escape

   I.M.Kadenko🇺🇦 · B. Biro🇭🇺 · A. Fenyvesi🇭🇺

   A new nuclear reaction channel on 197Au with the neutron as a projectile and a bound dineutron (^2n) in the output channel is considered based on available experimental observations. The dineutron is assumed to be formed as a particle-satellite, separated from the volume but not from the potential well of 196Au nucleus. The dineutron was identified by statistically significant radioactivity detection due to decay of 196gAu nuclei. Cross sections for the 197Au (n,^2n) 196gAu reaction are determined as 180 +/- 60 microbarns and 37 +/- 8 microbarns for [6.09-6.39] and [6.175-6.455] MeV energy ranges, correspondingly. Possible outcomes of dineutron detection near the surface of deformed nuclei are also raised and discussed.

   nucl-exEPL(2020)·9 citations
2. 02*

   First search for 2$\epsilon$ and $\epsilon {\beta }^{+}$ processes in ${}^{168}$Yb

   P.Belli🇮🇹 · R.Bernabei🇮🇹 · R.S.Boiko🇺🇦 · F.Cappella🇮🇹 · V.Caracciolo🇮🇹 · R.Cerulli🇮🇹 · F.A.Danevich🇺🇦 · M.L. di Vacri🇮🇹 · A.Incicchitti🇮🇹 · B.N.Kropivyansky🇺🇦 · M.Laubenstein🇮🇹 · S.Nisi🇮🇹 and 3 other authors

   The double-electron capture and the electron capture with positron emission in ${}^{168}$Yb have been investigated for the first time at the STELLA facility of the Gran Sasso underground laboratory (Italy) measuring 371 g of highly purified ytterbium oxide placed on the end-cap of a 465 cm${}^3$ ultra-low-background high purity Germanium detector (HPGe). No gamma associated to double beta processes in ${}^{168}$Yb have been observed after 2074 h of data taking. This has allowed setting the half-life limits on the level of $\lim T_{1/2}\sim$ $10^{14}-10^{18}$ yr at 90\% C.L. Particularly, a lower half-life limit on a possible resonant neutrinoless double-electron capture in ${}^{168}$Yb to the $(2{)}^{-}$ 1403.7 keV excited state of ${}^{168}$Er is set as $T_{1/2}\ge 1.9\times 10^{18}$ yr at 90\% C.L. Half-life limits $T_{1/2}^{2\nu (0\nu )}\ge 4.5(4.3)\times 10^{16}$ yr were set on the $2\nu (0\nu )2{\beta }^{-}$ decay of ${}^{176}$Yb to the $2^{+}$ 84.3 keV first excited level of ${}^{176}$Hf.

   nucl-exNPA(2019)·11 citations
3. 03*

   Neutron spin structure from polarized deuteron DIS with proton tagging

   W. Cosyn🇧🇪 · C. Weiss🇺🇸

   Polarized electron-deuteron deep-inelastic scattering (DIS) with detection of the spectator proton ("tagged DIS") enables measurements of neutron spin structure with maximal control of nuclear effects. We calculate the longitudinal spin asymmetries in polarized tagged DIS using methods of light-front nuclear structure and study their dependence on the measured proton momentum. Asymmetries can be formed with all three deuteron spin states ($\pm 1,0$) or the two maximum-spin states only ($\pm 1$, involving tensor polarization). The proton momentum dependence can be used to select pure S-wave configurations in the deuteron and eliminate D-wave depolarization (transverse momenta $p_{pT}\lesssim$ 100 MeV). Free neutron spin structure can be extracted model-independently through pole extrapolation of the tagged asymmetries. Such measurements could be performed at a future electron-ion collider (EIC) with polarized deuteron beams and forward proton detectors.

   ↳ hep-phnucl-exnucl-thPLB(2019)·10 citations
4. 04*

   (3+1)-dimensional dissipative relativistic fluid dynamics at non-zero net baryon density

   Lipei Du🇺🇸 · Ulrich Heinz🇺🇸

   Heavy-ion collisions at center-of-mass energies between 1 and 100 GeV/nucleon are essential to understand the phase diagram of QCD and search for its critical point. At these energies the net baryon density of the system can be high, and simulating its evolution becomes an indispensable part of theoretical modeling. We here present the (3+1)-dimensional diffusive relativistic hydrodynamic code BEShydro which solves the equations of motion of second-order Denicol-Niemi-Molnar-Rischke (DNMR) theory, including bulk and shear viscous currents and baryon diffusion currents. BEShydro features a modular structure that allows to easily turn on and off baryon evolution and different dissipative effects and thus to study their physical effects on the dynamical evolution individually. An extensive set of test protocols for the code, including several novel tests of the precision of baryon transport that can also be used to test other such codes, is documented here and supplied as a permanent part of the code package.

   ↳ nucl-thhep-phnucl-exphysics.comp-phComput.Phys.Commun.(2020)·98 citations
5. 05*

   Sensitivity analysis of the chiral magnetic effect observables using a multiphase transport model

   Ling Huang🇨🇳 · Mao-Wu Nie🇨🇳 · Guo-Liang Ma🇨🇳

   Because the traditional observable of charge-dependent azimuthal correlator $\gamma$ contains both contributions from the chiral magnetic effect (CME) and its background, a new observable of $R_{{\Psi }_m}$ has been recently proposed which is expected to be able to distinguish the CME from the background. In this study, we apply two methods to calculate $R_{{\Psi }_m}$ using a multiphase transport model without or with introducing a percentage of CME-induced charge separation. We demonstrate that the shape of final $R_{{\Psi }_2}$ distribution is flat for the case without the CME, but concave for that with an amount of the CME, because the initial CME signal survives from strong final state interactions. By comparing the responses of $R_{{\Psi }_2}$ and $\gamma$ to the strength of the initial CME, we observe that two observables show different nonlinear sensitivities to the CME. We find that the shape of $R_{{\Psi }_2}$ has an advantage in measuring a small amount of the CME, although it requires large event statistics.

   ↳ nucl-thhep-phnucl-exPRC(2020)·18 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.