Mon·Nov 28, 2016Monday·November 28, 2016

1. 01*

   A study of raining influence on the environmental radiation background spectra with HXMT/HE

   Xu-Fang Li · Cong-Zhan Liu🇨🇳 · Yi-Fei Zhang🇨🇳 · Zheng-Wei Li🇨🇳 · Xue-Feng Lu · Jian-Ling Zhao · Chang-Lin Zou🇨🇳 · Yu-Peng Xu🇺🇸 · Fang-Jun Lu🇨🇳

   Full functional and performance tests were performed many times before the Hard X-ray Modulation Telescope (HXMT) launch. During one of the tests, the count rate curves of the 18 High Energy Detectors (HED) have been found increased consistently within an interval of time. A further study on the correlation between the count rate and rainfall was carried out,and the increased net spectrum was also analyzed. The analysis results indicate that the short-lived 222Rn decay products (214Pb and 214Bi) in rainwater were responsible for the transient changes of the background radiation spectra in HEDs. The results show that the HXMT/HEDs have a good detection sensitivity on X/gamma rays, and the detector calibration results are effective.

   ↳ physics.ins-detastro-ph.IMnucl-ex0 citations
2. 02*

   Extracting kinetic freeze-out temperature and radial flow velocity from an improved Tsallis distribution

   Hai-Ling Lao🇨🇳 · Fu-Hu Liu🇨🇳 · Roy A. Lacey🇺🇸

   We analyze the transverse momentum ($p_T$) spectra of identified particles (${\pi }^{\pm }$, $K^{\pm }$, $p$, and $\bar{p}$) produced in gold-gold (Au-Au) and lead-lead (Pb-Pb) collisions over a $\sqrt{s_{NN}}$ (center-of-mass energy per nucleon pair) range from 14.5 GeV [one of the Relativistic Heavy Ion Collider (RHIC) energies] to 2.76 TeV [one of the Large Hadron Collider (LHC) energies]. For the spectra with a narrow $p_T$ range, an improved Tsallis distribution which is in fact the Tsallis distribution with radial flow is used. For the spectra with a wide $p_T$ range, a superposition of the improved Tsallis distribution and an inverse power-law is used. Both the extracted kinetic freeze-out temperature ($T_0$) and radial flow velocity (${\beta }_T$) increase with the increase of $\sqrt{s_{NN}}$, which indicates a higher excitation and larger expansion of the interesting system at the LHC. Both the values of $T_0$ and ${\beta }_T$ in central collisions are slightly larger than those in peripheral collisions, and they are independent of isospin and slightly dependent on mass.

   ↳ nucl-thhep-exhep-phnucl-exEPJA(2017)·51 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.