arXiv subjects

Rama Prasad Adak

Publications and source records attributed to Rama Prasad Adak.

2 recordsLinked to original sources

arXiv2017

Centrality dependence of chemical freeze-out parameters from net-proton and net-charge fluctuations using hadron resonance gas model

We estimate chemical freeze-out parameters in HRG and EVHRG model by fitting the experimental information of net-proton and net-charge fluctuations measured in Au + Au collisions by the STAR collaboration at RHIC. We observe that chemical freeze-out parameters obtained from lower and higher order fluctuations are though almost same for $\sqrt{s_{NN}} > 27$ GeV, tend to deviate from each other at lower $\sqrt{s_{NN}}$. Moreover, these separations increase with decrease of $\sqrt{s_{NN}}$ and for a fixed $\sqrt{s_{NN}}$ increase towards central collisions. Furthermore, we observe an approximate scaling behaviour of $(μ_B/T)/(μ_B/T)_{central}$ with $(N_{part})/(N_{part})_{central}$ for the parameters estimated from lower order fluctuations for 11.5 GeV $\le \sqrt{s_{NN}} \le$ 200 GeV. Scaling is violated for the parameters estimated from higher order fluctuations for $\sqrt{s_{NN}}= 11.5$ and 19.6 GeV. It is observed that the chemical freeze-out parameter, which can describe $σ^2/M$ of net-proton very well in all energies and centralities, can not describe the $sσ$ equally well and vice versa.

nucl-th↗

arXiv2016

Performance of a large size triple GEM detector at high particle rate for CBM Experiment at FAIR

In CBM Experiment at FAIR, dimuons will be detected by a Muon Chamber (MUCH) consisting of segmented absorbers of varying widths and tracking chambers sandwiched between the absorber-pairs. In this fixed target heavy-ion collision experiment, operating at highest interaction rate of $10~MHz$ for $Au+Au$ collision, after the first MUCH detector station in its inner radial ring will face a particle rate of $1~MHz/cm^2$. To operate at such a high particle density, GEM technology based detectors have been selected for the first two stations of MUCH. We have reported earlier the performance of several small-size GEM detector prototypes built at VECC for use in MUCH. In this work, we report on a large GEM chamber prototype tested with proton beam of momentum $2.36~GeV/c$ at COSY-Jüelich Germany. The detector was read out using nXYTER ASIC operated in self-triggering mode. An efficiency higher than $96\%$ at $ΔV_{GEM}~=~375.2~V$ was achieved. The variation of efficiency with the rate of incoming protons has been found to vary within $2\%$ when tested up to a maximum rate of $2.8~MHz/cm^2$. The gain was found to be stable at high particle rate with a maximum variation of $\sim~9\%$.

physics.ins-det↗