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


Khachatryan V., Sirunyan A., Tumasyan A., Adam W., Bergauer T., Dragicevic M., ...More

Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics, vol.743, pp.383-402, 2015 (SCI-Expanded) identifier

Abstract

© 2015 CERN for the benefit of the CMS Collaboration.A 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=8TeV, 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 20.7fb-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, 7