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Title: Measurement of the production cross section ratio σ(χ b2(1P)) / σ(χ b1(1P)) in pp collisions at √(s) = 8 TeV

Our measurement of the production cross section ratio σ(χ b2(1P))/σ(χ b1(1P)) is presented. The χ b1(1P) and χ b2(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 χ b1,2(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, |η γ|<1.0; the Υ(1S) rapidity, |y Υ|<1.5; and the Υ(1S) transverse momentum, 7T Υ<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 χ b 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