Z0 and J/psi production in Pb+Pb collisions at sqrt(sNN) = 2.76 TeV
초록/요약
The new era of the Large Hadron Collider (LHC) in heavy-ion experiments has come up. It opens the chance to probe physics in new regime of center of mass energy 14 times larger than previous experiment, which is performed by the Relativistic Heavy Ion Collider (RHIC). Thanks to such a high center of mass energy available at the LHC, the dimuon analysis can reach up to high mass region such as W+- and Z0 bosons in the heavy-ion collisions. This measurement during November and December in 2010 was the first trial to observe the Z0 bosons in the history of heavy-ion experiments. The study of Z0 and J/psi production is very important to understand modifications in the Quark-Gluon-Plasma (QGP). Z0 bosons are expected to be un-modified by the presence of the QGP. On the other hand, J/psis are expected to be modified by QGP. Therefore, we measured the comparison of the results of the nuclear modification factor (RAA), which is the ratio of the yields normalized by pp cross section scaled by binary collisions, rises the attention of the fans who love dimuon physics in heavy-ion and will be shown in this thesis. The analysis is performed with the data which were taken in pp and PbPb collisions at \sqrt(s_NN) = 2.76 TeV with 7.2 \mub^−1. In addition, the CMS double muon triggers for both pp and PbPb play a important role not only to save low-pT muons from quarkonia, including Z0 bosons, but also to reject background muons coming from decay flight in or punch through hadrons. Therefore we needed to prepare the trigger algorithm for pp data in 2010. The detail study of them will be described in this thesis.
more목차
1 Introduction
2 Theoretical Overview and Experimental Status
3 The LHC Machine and The CMS experiment
4 CMS Muon Trigger System
5 Data Selection
6 Muon reconstruction heavy-ion collisions
7 Measurement of Z0 boson in P bP b collisions
8 Measurement of J/psi in P bP b collisions
9 Conclusion