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Title: Measurement of the production cross section ratio σ(χb2(1P)) / σ(χb1(1P)) in pp collisions at √(s) = 8 TeV

Our measurement of the production cross section ratio σ(χb2(1P))/σ(χb1(1P)) is presented. The χb1(1P) and χb2(1P) bottomonium states, promptly produced in pp collisions at √(s) = 8 TeV , are detected by the CMS experiment at the CERN LHC through their radiative decays χb1,2(1P)→Υ(1S)+γ. The emitted photons are measured through their conversion to e+e- pairs, whose reconstruction allows the two states to be resolved. The Υ(1S) is measured through its decay to two muons. An event sample corresponding to an integrated luminosity of 20.7 fb-1 is used to measure the cross section ratio in a phase-space region defined by the photon pseudorapidity, |ηγ|<1.0; the Υ(1S) rapidity, |yΥ|<1.5; and the Υ(1S) transverse momentum, 7TΥ<40 GeV . Finally, the cross section ratio shows no significant dependence on the Υ(1S) transverse momentum, with a measured average value of 0.85± 0.07 (stat + syst) ± 0.08 (BF), where the first uncertainty is the combination of the experimental statistical and systematic uncertainties and the second is from the uncertainty in the ratio of the χb branching fractions.
  1. Yerevan Physics Inst. (YerPhI) (Armenia). et al.
Publication Date:
OSTI Identifier:
Report Number(s):
FERMILAB-PUB-14-367-CMS; CERN-PH-EP-2014-217; CMS-BPH-13-005
Journal ID: ISSN 0370-2693; arXiv eprint number arXiv:1409.5761; TRN: US1601022
Grant/Contract Number:
Published Article
Journal Name:
Physics Letters. Section B
Additional Journal Information:
Journal Volume: 743; Journal ID: ISSN 0370-2693
Research Org:
Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
CMS Collaboration
Country of Publication:
United States
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CMS; Quarkonium production; P-wave states; Bottomonium