Thu·May 7, 2020Thursday·May 7, 2020

1. 01*

   Comprehensive measurements of cross sections and spin observables of the three-body break-up channel in deuteron-deuteron scattering at 65 MeV/nucleon

   R. Ramazani-Sharifabadi🇮🇷 · H.R. Amir-Ahmadi🇳🇱 · M.T. Bayat · A. Deltuva🇱🇹 · M. Eslami-Kalantari · N. Kalantar-Nayestanaki🇳🇱 · St. Kistryn🇵🇱 · A. Kozela🇵🇱 · M. Mahjour-Shafiei🇮🇷 · H. Mardanpour🇳🇱 · J.G. Messchendorp🇳🇱 · M. Mohammadi-Dadkan🇳🇱 and 3 other authors

   Detailed measurements of five-fold differential cross sections and a rich set of vector and tensor analyzing powers of the 2H(d; dp)n break-up process using polarized deuteron-beam energy of 65 MeV/nucleon with a liquid-deuterium target are presented. The experiment was conducted at the AGOR facility at KVI using the BINA 4Pi-detection system. We discuss the analysis procedure including a thorough study of the systematic uncertainties. The results can be used to examine upcoming state-of-the-art calculations in the four-nucleon scattering domain, and will, thereby, provide further insights into the dynamics of three- and four-nucleon forces in few-nucleon systems. The results of coplanar configurations are compared with the results of recent theoretical calculations based on the Single-Scattering Approximation (SSA). Through these comparisons, the validity of SSA approximation is investigated in the Quasi-Free (QF) region.

   nucl-exEPJA(2020)·5 citations
2. 02*

   Intensities of the $\gamma$-ray emissions following the ${}^{111}Sn$ decay determined via photonuclear reaction yield measurements

   A. Chekhovska · Ye. Skakun · I. Semisalov · S. Karpus · V. Kasilov

   The intensities of the ten strongest $\gamma$-ray transitions following the ${}^{111}Sn$ ($T_{1/2}$=35.3 m) decay have been determined via comparison of the two sets of the experimental photonucleon reaction yields driven using the traditional activation equation and the activation equation for the genetically coupled radioactive nuclei. The found absolute intensities of the $\gamma$-ray transitions in question were happened to be noticeably different from the currently recommended values.

   nucl-exphysics.app-phNucl.Instrum.Meth.B(2022)·0 citations
3. 03*

   One fluid might not rule them all

   You Zhou🇩🇰 · Wenbin Zhao🇨🇳 · Koichi Murase🇨🇳 · Huichao Song🇨🇳

   In this proceeding, we present our recent investigations on hydrodynamic collectivity in high-multiplicity proton--proton collisions at $\sqrt{s}=$ 13 TeV using the VISHNU hybrid model with different initial condition models, called HIJING, super-MC and TRENTo. We find that with carefully tuned parameters, hydrodynamic simulations can give reasonable descriptions of the measured two-particle correlations. However, multi-particle single and mixed harmonics cumulants can not be described by hydrodynamics with these three initial conditions, even for the signs in a few cases. Further studies show that the non-linear response plays an important role in the hydrodynamic expansion of the p--p systems. Such an effect can change $c_2\{4\}$ from a negative value in the initial state to a positive value in the final state. The failure of the hydrodynamic description of multi-particle cumulant triggers the questions on whether the hydrodynamics can rule all collision systems, including p--p collisions at the LHC.

   ↳ nucl-thnucl-exNPA(2021)·14 citations
4. 04*

   The global geometrical property of jet events in high-energy nuclear collisions

   Shi-Yong Chen🇨🇳 · Wei Dai🇨🇳 · Shan-Liang Zhang🇨🇳 · Qing Zhang🇨🇳 · Ben-Wei Zhang🇨🇳

   We present the first theoretical study of medium modifications of the global geometrical pattern, i.e., transverse sphericity ($S_{\perp }$) distribution of jet events with parton energy loss in relativistic heavy-ion collisions. In our investigation, POWHEG+PYTHIA is employed to make an accurate description of transverse sphericity in the p+p baseline, which combines the next-to-leading order (NLO) pQCD calculations with the matched parton shower (PS). The Linear Boltzmann Transport (LBT) model of the parton energy loss is implemented to simulate the in-medium evolution of jets. We calculate the event normalized transverse sphericity distribution in central Pb+Pb collisions at the LHC, and give its medium modifications. An enhancement of transverse sphericity distribution at small $S_{\perp }$ region but a suppression at large $S_{\perp }$ region are observed in A+A collisions as compared to their p+p references, which indicates that in overall the geometry of jet events in Pb+Pb becomes more pencil-like. We demonstrate that for events with 2 jets in the final-state of heavy-ion collisions, the jet quenching makes the geometry more sphere-like with medium-induced gluon radiation. However, for events with $\ge 3$~jets, parton energy loss in the QCD medium leads to the events more pencil-like due to jet number reduction, where less energetic jets may lose their energies and then fall off the jet selection kinematic cut. These two effects offset each other and in the end result in more jetty events in heavy-ion collisions relative to that in p+p.

   ↳ hep-phnucl-exnucl-thEPJC(2020)·9 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.