Fri·Jan 10, 2020Friday·January 10, 2020

1. 01*

   Non-monotonic energy dependence of net-proton number fluctuations

   STAR Collaboration: J. Adam · L. Adamczyk · J. R. Adams · J. K. Adkins · G. Agakishiev · M. M. Aggarwal · Z. Ahammed · I. Alekseev · D. M. Anderson · A. Aparin · E. C. Aschenauer · M. U. Ashraf and 346 other authors

   Non-monotonic variation with collision energy ($\sqrt{s_{\mathrm{NN}}}$) of the moments of the net-baryon number distribution in heavy-ion collisions, related to the correlation length and the susceptibilities of the system, is suggested as a signature for the Quantum Chromodynamics (QCD) critical point. We report the first evidence of a non-monotonic variation in kurtosis times variance of the net-proton number (proxy for net-baryon number) distribution as a function of \rootsnn with 3.1$\sigma$ significance, for head-on (central) gold-on-gold (Au+Au) collisions measured using the STAR detector at RHIC. Data in non-central Au+Au collisions and models of heavy-ion collisions without a critical point show a monotonic variation as a function of $\sqrt{s_{\mathrm{NN}}}$.

   nucl-exhep-exhep-phnucl-thPRL(2021)·380 citations
2. 02*

   The determination of {\alpha}-spectroscopic factors and ANC of 16O states using 12C(20Ne,16O)16O reaction at Elab=150 MeV incident energy

   Ashok Kumar Mondal🇮🇳 · C. Basu · S. Adhikari🇩🇪 · C. Bhattacharya🇮🇳 · T. K. Rana · S. Kundu🇮🇳 · S. Manna · R. Pandey · P. Roy · A. Sen · J. K. Meena🇮🇳 · A. K. Saha and 7 other authors

   The 12C(20Ne,16O)16O {\alpha}-transfer reaction at Elab=150 MeV is first time used to determine the ANC of the 6.92 MeV and 7.12 MeV states of 16O. The 20Ne+ 12C potential parameters are also obtained from elastic scattering. The direct reaction code FRESCO is used to determine the {\alpha}-spectroscopy factor (S{\alpha} ) of the three states of 16O (6.92 MeV, 7.12 MeV and 11.52 MeV) and ANC of the two states (6.92 MeV and 7.12 MeV) of 16O. The extracted ANC and S{\alpha} are compareable to previous measurements.

   nucl-ex0 citations
3. 03*

   Emergence of Quark-Gluon Plasma Phenomena

   Jan Fiete Grosse-Oetringhaus🇨🇭

   The discovery of QGP phenomena in small collision systems like pp and p-Pb collisions have challenged the basic paradigms of heavy-ion and high-energy physics. These proceedings give a brief overview of the key findings and their implications, as well as today's experimental and theoretical situation. An outlook of future measurement is made.

   nucl-exhep-exhep-phPoS(2020)·3 citations
4. 04*

   An {\it ab-initio} Gamow shell model approach with a core

   B. S. Hu🇨🇳 · Q. Wu🇨🇳 · J. G. Li🇨🇳 · Y. Z. Ma🇨🇳 · Z. H. Sun🇨🇳 · N. Michel🇨🇳 · F. R. Xu🇨🇳

   Gamow shell model (GSM) is usually performed within the Woods-Saxon (WS) basis in which the WS parameters need to be determined by fitting experimental single-particle energies including their resonance widths. In the multi-shell case, such a fit is difficult due to the lack of experimental data of cross-shell single-particle energies and widths. In this paper, we develop an {\it ab-initio} GSM by introducing the Gamow Hartree-Fock (GHF) basis that is obtained using the same interaction as the one used in the construction of the shell-model Hamiltonian. GSM makes use of the complex-momentum Berggren representation, then including resonance and continuum components. Hence, GSM gives a good description of weakly bound and unbound nuclei. Starting from chiral effective field theory and employing many-body perturbation theory (MBPT) (called nondegenerate $\hat{Q}$-box folded-diagram renormalization) in the GHF basis, a multi-shell Hamiltonian ({\it sd-pf} shells in this work) can be constructed. The single-particle energies and their resonance widths can also been obtained using MBPT. We investigated ${}^{23-28}$O and ${}^{23-31}$F isotopes, for which multi-shell calculations are necessary. Calculations show that continuum effects and the inclusion of the {\it pf} shell are important elements to understand the structure of nuclei close to and beyond driplines.

   ↳ nucl-thnucl-exPLB(2020)·40 citations
5. 05*

   Dynamics of the linear-chain alpha cluster in microscopic time-dependent relativistic density functional theory

   Z. X. Ren🇨🇳 · P. W. Zhao🇨🇳 · J. Meng🇨🇳

   The time-dependent covariant density functional theory in 3D lattice space has been developed and applied to investigate the microscopic dynamics of the linear-chain cluster states for carbon isotopes in the reactions ${}^4$He${+}^8$Be and ${}^4$He${+}^{10}$Be without any symmetry assumptions. By examining the density distribution and its time evolutions, the structure and dynamics of the linear-chain states are analyzed, and the quasiperiodic oscillations of the clusters are revealed. For ${}^4$He${+}^8$Be, the linear-chain states evolve to a triangular configuration and then to a more compact shape. In contrast, for ${}^4$He${+}^{10}$Be, the lifetime of the linear-chain states is much more prolonged due to the dynamical isospin effects by the valence neutrons which slow down the longitudinal oscillations of the clusters and persist the linear-chain states. The dependence of the linear chain survival time and dynamical isospin effects on impact parameters have been illustrated as well.

   ↳ nucl-thnucl-exPLB(2020)·35 citations
6. 06*

   Baryon production from small to large collision systems at ALICE

   Omar Vazquez Rueda🇸🇪

   Studies of the production of light- and heavy-flavor baryons are of prominent importance to characterize the partonic phase created in ultrarelativistic heavy-ion collisions and to investigate hadronization mechanisms at the LHC. Studies performed in p-Pb and pp collisions have revealed unexpected features, qualitatively similar to what is observed in larger collision systems and, in the charm sector, not in line with the expectations from ${\mathrm{e}}^{+}{\mathrm{e}}^{-}$ and ${\mathrm{e}}^{-}\mathrm{p}$ interactions. The ALICE experiment has exploited its excellent tracking and particle identification capabilities down to low transverse momentum to perform an extensive study of protons, hyperons and charmed baryons. In this paper, a discussion of the most recent results on light (protons and hyperons) and heavy-flavor $({\Lambda }_{\mathrm{c}})$ baryon production is presented, together with a comparison to phenomenological models.

   ↳ hep-exnucl-exPoS(2020)·1 citation
7. 07*

   A modular apparatus for use in high-precision measurements of parity violation in polarized eV neutron transmission`

   D. C. Schaper · C. Auton · L. Barrón-Palos · M. Borrego · A. Chavez · L. Cole · C. B. Crawford · J. Curole · H. Dhahri · K. A. Dickerson · J. Doskow · W. Fox and 15 other authors

   We describe a modular apparatus for use in parity-violation measurements in epithermal neutron-nucleus resonances with high instantaneous neutron fluxes at the Manuel Lujan Jr.\ Neutron Scattering Center at Los Alamos National Laboratory. This apparatus is designed to conduct high-precision measurements of the parity-odd transmission asymmetry of longitudinally polarized neutrons through targets containing nuclei with p-wave neutron-nucleus resonances in the 0.1-10 eV energy regime and to accommodate a future search for time reversal violation in polarized neutron transmission through polarized nuclear targets. The apparatus consists of an adjustable neutron and gamma collimation system, a \(^3\)He-${}^4$He ion chamber neutron flux monitor, two identical cryostats for target cooling, an adiabatic eV-neutron spin flipper, a near-unit efficiency \(^6\)Li-\(^{7}\)Li scintillation detector operated in current mode, a flexible CAEN data acquisition system, and a neutron spin filter based on spin-exchange optical pumping of ${}^3$He gas. We describe the features of the apparatus design devoted to the suppression of systematic errors in parity-odd asymmetry measurements. We describe the configuration of the apparatus used to conduct a precision measurement of parity violation at the 0.7 eV p-wave resonance in ${}^{139}$La which employs two identical ${}^{139}$La targets, one to polarize the beam on the p-wave resonance using the weak interaction and one to analyze the polarization.

   ↳ physics.ins-detnucl-exNucl.Instrum.Meth.A(2020)·6 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.