Thu·Jan 7, 2016Thursday·January 7, 2016

1. 01*

   Higher Moments of Net-Particle Multiplicity Distributions

   Jochen Thäder (STAR Collaboration)🇺🇸

   Studying fluctuations of conserved quantities, such as baryon number, strangeness, and charge, provides insights into the properties of matter created in high-energy nuclear collisions. Lattice QCD calculations suggest that higher moments of these quantities are sensitive to the phase structure of the hot and dense nuclear matter created in such collisions. In this paper, we present first experimental results of volume and temperature independent cumulant ratios of net-charge and net-proton distributions in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}=14.5\mathrm{GeV}$ completing the first RHIC Beam Energy Scan (BES-I) program for $\sqrt{s_{\mathrm{NN}}}=7.7\mathrm{to}200\mathrm{GeV}$, together with the first measurement of fully corrected net-kaon results, measured with the STAR detector at RHIC at mid-rapidity and a transverse momentum up to $p_{\mathrm{T}}=2GeV/c$. The pseudo-rapidity dependence of the $\sqrt{s_{\mathrm{NN}}}=14.5\mathrm{GeV}$ net-charge cumulant ratios is discussed. The estimated uncertainties on the ratio $c_4/c_2$, the most statistics-hungry of the present observables, at $\sqrt{s_{\mathrm{NN}}}=7.7\mathrm{GeV}$ in the upcoming RHIC BES-II program will also be presented.

   nucl-exNPA(2016)·53 citations
2. 02*

   Charge-dependent anisotropic flow in Cu+Au collisions

   Takafumi Niida (for the STAR Collaboration)🇺🇸

   We present the first measurements of charge-dependent directed flow in Cu+Au collisions at t $\sqrt{s_{NN}}$ = 200 GeV. The directed flow has been measured as functions of the transverse momentum and pseudorapidity with the STAR detector. The results show a small but finite difference between positively and negatively charged particles. The difference is qualitatively explained by the patron-hadron-string-dynamics (PHSD) model including the effect of the electric field, but much smaller than the model calculation, which indicates only a small fraction of all final quarks are created within the lifetime of the initial electric field. Higher-order azimuthal anisotropic flow is also presented up to the fourth-order for unidentified charged particles and up to the third-order for identified charged particles ({\pi}, K, and p). For unidentified particles, the results are reasonably described by the event-by-event viscous hydrodynamic model with {\eta}/s=0.08-0.16. The trends observed for identified particles in Cu+Au collisions are similar to those observed in symmetric (Au+Au) collisions.

   nucl-exNPA(2016)·8 citations
3. 03*

   Mini-Orange Spectrometer at CIAE

   Yun Zheng🇨🇳 · Xiao-Guang Wu🇨🇳 · Guang-Sheng Li · Cong-Bo Li · Chuang-Ye He🇨🇳 · Qi-Ming Chen🇨🇳 · Jian Zhong · Wen-Kui Zhou · Li-Tao Deng · Bao-Ji Zhu

   A Mini-Orange spectrometer used for in-beam measurements of internal conversion electrons, which consists of a Si(Li) detector and different sets of SmO${}_5$ permanent magnets for filtering and transporting the conversion electrons to the Si(Li) detector, has been developed at China Institute of Atomic Energy. The working principle and configuration of the Mini-Orange spectrometer are described. The performance of the setup is illustrated by measured singles conversion electron spectra using the Mini-Orange spectrometer.

   ↳ physics.ins-detnucl-exCPC(2016)·2 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.