Measurements of the Charm Jet Cross Section and Nuclear Modification Factor in pPb Collisions at √s[subscript NN] = 5.02 TeV
The CMS Collaboration presents the first measurement of the differential cross section of jets from charm quarks produced in proton–lead (pPb) collisions at a nucleon–nucleon center-of-mass energy of √s[subscript NN] = 5.02 TeV, as well as results from charm quark jets in proton–proton (pp) collisio...
| Summary: | The CMS Collaboration presents the first measurement of the differential cross section of jets from charm quarks produced in proton–lead (pPb) collisions at a nucleon–nucleon center-of-mass energy of √s[subscript NN] = 5.02 TeV, as well as results from charm quark jets in proton–proton (pp) collisions at √s = 2.76 and 5.02 TeV. By comparing the yields of the pPb and pp collision systems at the same energy, a nuclear modification factor for charm jets from 55 to 400 GeV/c in pPb collisions at √s[subscript NN] = 5.02TeV of Rp[subscript A] = 0.92 ± 0.07(stat) ± 0.11(syst) is obtained. This is consistent with an absence of final-state energy loss for charm quarks in pPb collisions. In addition, the fraction of jets coming from charm quarks is found to be consistent with that predicted by PYTHIA 6 for pp collisions at √s = 2.76 and 5.02 TeV, and is independent of the jet transverse momentum from 55 to 400 GeV/c. Keywords: CMS; Heavy ions; Charm-tagging; Heavy-flavor |
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