Tue·Jun 19, 2018Tuesday·June 19, 2018

1. 01*

   Transverse Momentum Balance and Angular Distribution of $b\bar{b}$ Dijets in Pb+Pb collisions

   Wei Dai🇨🇳 · Sa Wang🇨🇳 · Shan-Liang Zhang🇨🇳 · Ben-Wei Zhang🇨🇳 · Enke Wang🇨🇳

   The productions of inclusive b-jet and $b\bar{b}$ dijets in Pb+Pb collisions have been investigated by considering the heavy quark and the light quark in-medium evolution simultaneously. The initial hard processes of inclusive b-jet and $b\bar{b}$ dijets productions are described by a next-to-leading order (NLO) plus parton shower Monte Carlo (MC) event generator SHERPA which can be well-matched with the experimental data in p+p collisions. The framework combines the Langevin transport model to describe the evolution of the bottom quark also its collisional energy loss and the higher-twist description to consider the radiative energy loss of both the bottom and light quarks. We compare the theoretical simulation of inclusive jet and inclusive b-jet $R_{\mathrm{AA}}$ in Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}=2.76$ TeV with the experimental data, and then present the theoretical simulation of the momentum balance of the $b\bar{b}$ dijet in Pb+Pb collisions at $5.02$ TeV with the recent CMS data for the first time. A similar trend as that in inclusive dijets has been observed in $b\bar{b}$ dijets, the production distribution is shifted to smaller $x_J$ due to the jet quenching effect. At last, the prediction of the normalized azimuthal angle distribution of the $b\bar{b}$ dijet in Pb+Pb collisions at $5.02$ TeV has been reported. The medium induced energy loss effect of the $b\bar{b}$ dijets will overall suppress its production, but the same side ($\Delta \varphi \to 0$ region) suffers more energy loss than away side ($\Delta \varphi \to \pi$ region), therefore lead to the suppression on the same side and the enhancement on the away side in the normalized azimuthal angle distribution in A+A collisions.

   ↳ nucl-thhep-phnucl-exCPC(2020)·42 citations
2. 02*

   A High Precision Signals Readout System for Micromegas Detector Based on the VMM

   Shuang. Zhou · Shengquan. Liu · Peng. Miao · Xinxin. Wang · Feng. Li · Ge. Jin🇺🇸 · Zhilei. Zhang · Tianru. Geng

   Micromegas detector is a gas detector with parallel plate structure, and it consists of a conversion gap in which radiations liberate ionization electrons and a thin amplification gap. The signal of the micromegas detector consists of two parts: the electron peak and the ion tail. The electronic signal just keeps few nanoseconds, which is used for precise time measurement. The ion signal carries most of the signal energy, and it is used to reconstruct particle energy. The micromegas detector has the advantages of high counting rate, high gain, good time resolution and position resolution, excellent radiation-hardened performance, large sensitive area and readout convenience. This paper introduces a signals readout electronics system for micromegas detector based on VMM chips. The VMM is the front end ASIC to be used in the front end electronics readout system of both the micromegas and sTGC detectors of the New Small Wheels Upgrade project. The VMM is designed by Brookhaven National Laboratory, and each chip is composed of 64 linear front-end channels. Each channel integrates a low-noise charge amplifier (CA) with adaptive feedback, test capacitor, and adjustable polarity (to process either positive or negative charge). Based on those characteristics, the VMM is applicable for the signals readout system of multichannel detectors. The readout system consists of three parts: the front-end board, the data acquisition board, and the host computer with the control software.

   ↳ physics.ins-detnucl-ex0 citations
3. 03*

   A new and finite family of solutions of hydrodynamics. Part I: Fits to pseudorapidity distributions

   T. Csorgo🇭🇺 · G. Kasza🇭🇺 · M. Csanad🇭🇺 · Z. F. Jiang🇨🇳

   We highlight some of the interesting properties of a new and finite, exact family of solutions of 1 + 1 dimensional perfect fluid relativistic hydrodynamics. After reviewing the main properties of this family of solutions, we present the formulas that connect it to the measured rapidity and pseudo-rapidity densities and illustrate the results with fits to p+p collisions at 8 TeV and Pb+Pb collisions at $\sqrt{s_{NN}}=5.02$ TeV.

   ↳ nucl-thhep-exhep-phnucl-exActa Phys.Polon.B(2019)·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.