Charged-particle nuclear modification factors in PbPb and pPb collisions at √sNN=5.02 TeV
The spectra of charged particles produced within the pseudorapidity window |η| < 1 at √ sNN = 5.02 TeV are measured using 404 µb −1 of PbPb and 27.4 pb−1 of pp data collected by the CMS detector at the LHC in 2015. The spectra are presented over the transverse momentum ranges spanning 0.5 &...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English English |
| Published: |
Springer Verlag
2017
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| Subjects: | |
| Online Access: | http://irep.iium.edu.my/62596/ http://irep.iium.edu.my/62596/ http://irep.iium.edu.my/62596/ http://irep.iium.edu.my/62596/2/Charged-particle%20nuclear%20modification%20factors%20in%20PbPb_scopus.pdf http://irep.iium.edu.my/62596/13/62596_Charged-particle%20nuclear%20modification%20factors.pdf |
| Summary: | The spectra of charged particles produced within the pseudorapidity window |η| < 1
at √
sNN = 5.02 TeV are measured using 404 µb
−1 of PbPb and 27.4 pb−1
of pp data
collected by the CMS detector at the LHC in 2015. The spectra are presented over the
transverse momentum ranges spanning 0.5 < pT < 400 GeV in pp and 0.7 < pT <
400 GeV in PbPb collisions. The corresponding nuclear modification factor, RAA, is
measured in bins of collision centrality. The RAA in the 5% most central collisions
shows a maximal suppression by a factor of 7–8 in the pT region of 6–9 GeV. This
dip is followed by an increase, which continues up to the highest pT measured, and
approaches unity in the vicinity of pT = 200 GeV. The RAA is compared to theoretical
predictions and earlier experimental results at lower collision energies. The newly
measured pp spectrum is combined with the pPb spectrum previously published by
the CMS Collaboration to construct the pPb nuclear modification factor, RpA, up to
120 GeV. For pT > 20 GeV, RpA exhibits weak momentum dependence and shows a
moderate enhancement above unity. |
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