First measurement of jet mass in Pb-Pb and p-Pb collisions at the LHC
First measurement of jet mass in Pb-Pb and p-Pb collisions at the LHC
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DOI：
10.1016/j.physletb.2017.11.044
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发表时间：
2017-02
影响因子：
4.4
通讯作者：
Alice Collaboration
中科院分区：
文献类型：
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作者：
Alice Collaboration
本文首次测量了在√sNN= 2.76 TeV和√sNN= 5.02 TeV条件下，Pb-Pband p - pb碰撞中的射流质量。在对撞机能量的核碰撞中产生的热量子色动力学（QCD）物质中，射流能量和射流质量对射流猝灭都很敏感。利用反ktjet算法和分辨率参数R= 0.4从带电粒子重建射流。射流的测量范围为伪速度范围| η射流|< 0.5，横向动量为60gev /c ~ 120gev /c。中心pb - pb碰撞中射流质量的测量与p - preference碰撞中测量的射流质量、真空事件发生器和包括射流淬火在内的模型进行了比较。在不确定度范围内，我们观察到铅-铅中心碰撞的喷流质量与p - preference测量值是一致的。此外，在这封信中考虑的淬火模型中，测量到的铅-铅碰撞中的射流质量不能再现，并且在系统不确定度内与PYTHIA预期一致。
This letter presents the first measurement of jet mass in Pb–Pband p–Pbcollisions at√ sNN= 2.76 TeV and√ sNN= 5.02 TeV, respectively. Both the jet energy and the jet mass are expected to be sensitive to jet quenching in the hot Quantum Chromodynamics (QCD) matter created in nuclear collisions at collider energies. Jets are reconstructed from charged particles using the anti-kTjet algorithm and resolution parameter R= 0.4. The jets are measured in the pseudorapidity range| ηjet|< 0.5 and in three intervals of transverse momentum between 60 GeV/cand 120 GeV/c. The measurement of the jet mass in central Pb–Pbcollisions is compared to the jet mass as measured in p–Pbreference collisions, to vacuum event generators, and to models including jet quenching. It is observed that the jet mass in central Pb–Pbcollisions is consistent within uncertainties with p–Pbreference measurements. Furthermore, the measured jet mass in Pb–Pbcollisions is not reproduced by the quenching models considered in this letter and is found to be consistent with PYTHIA expectations within systematic uncertainties.