Thu·Jan 25, 2018Thursday·January 25, 2018

1. 01*

   Beam energy dependence of the anisotropic flow coefficients v${}_n$

   Niseem Magdy (For the STAR Collaboration)🇺🇸

   Recent STAR measurements of the anisotropic flow coefficients, v${}_n$, are presented for Au+Au collisions spanning the beam energy range $\sqrt{s_{NN}}=7.7-200$~GeV. The measurements indicate dependences on harmonic number, $n$, transverse momentum ($p_T$), pseudorapidity ($\eta$), collision centrality ($\mathrm{cent}$) and beam energy ($\sqrt{s_{NN}}$) which could serve as important constraints to test different initial-state models and to aid precision extraction of the temperature dependence of the specific shear viscosity.

   nucl-exPoS(2018)·11 citations
2. 02*

   Differential cross section and photon-beam asymmetry for the gamma p -> pi- Delta++(1232) reaction at forward pi- angles for Egamma=1.5-2.95 GeV

   H. Kohri🇯🇵 · S.H. Shiu🇹🇼 · W.C. Chang🇹🇼 · Y. Yanai🇯🇵 · D.S. Ahn🇯🇵 · J.K. Ahn🇰🇷 · J.Y. Chen🇹🇼 · S. Date🇯🇵 · H. Ejiri🇯🇵 · H. Fujimura🇯🇵 · M. Fujiwara🇯🇵 · S. Fukui🇯🇵 and 37 other authors

   Differential cross sections and photon-beam asymmetries for the gamma p -> pi- Delta++(1232) reaction have been measured for 0.7<cos(theta)<1 and Egamma=1.5-2.95 GeV at SPring-8/LEPS. The first-ever high statistics cross section data are obtained in this kinematical region, and the asymmetry data for 1.5<Egamma(GeV)<2.8 are obtained for the first time. This reaction has a unique feature for studying the production mechanisms of a pure $u\bar{u}$ quark pair in the final state from the proton. Although there is no distinct peak structure in the cross sections, a non-negligible excess over the theoretical predictions is observed at Egamma=1.5-1.8 GeV. The asymmetries are found to be negative in most of the present kinematical regions, suggesting the dominance of pi-exchange in the t-channel. The negative asymmetries at forward meson production angles are different from the asymmetries previously measured for the photoproduction reactions which produce a $d\bar{d}$ or an $s\bar{s}$ quark pair in the final state. Advanced theoretical models introducing nucleon resonances and additional unnatural parity exchanges are needed to reproduce the present data.

   nucl-exPRL(2018)·8 citations
3. 03*

   Energy dependence of cross section of photonuclear reactions on indium isotopes

   V. I. Zhaba · I. I. Haysak · A. M. Parlag · V. S. Bohinyuk · M. M. Lazorka

   Experimental isomeric yield ratios for the 113In({\gamma},n)112m,gIn reactions on the betatron B25/30 bremsstrahlung gamma beam of energy range 12-25 MeV are measured. Effective cross-sections of ({\gamma},n)-reactions with 112mIn and 114mIn isomers output are calculated. The Penfold-Leiss and Tikhonov methods are applied to solve the Volterra integral equation. The obtained experimental cross-sections are compared with theoretical calculations using the TALYS-1.6 code.

   nucl-exProb.Atomic Sci.Technol.(2018)·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.