Abstract
Differential cross sections as a function of transverse momentum pT are presented for the production of ϒ(nS) (n = 1, 2, 3) states decaying into a pair of muons. Data corresponding to an integrated luminosity of 4.9fb−1 in pp collisions at s=7TeV were collected with the CMS detector at the LHC. The analysis selects events with dimuon rapidity |y|<1.2 and dimuon transverse momentum in the range 10<pT<100GeV. The measurements show a transition from an exponential to a power-law behavior at pT≈20GeV for the three ϒ states. Above that transition, the ϒ(3S) spectrum is significantly harder than that of the ϒ(1S). The ratios of the ϒ(3S) and ϒ(2S) differential cross sections to the ϒ(1S) cross section show a rise as pT increases at low pT, then become flatter at higher pT.
Highlights
IntroductionAt the CERN LHC, the CMS [1,2], ATLAS [3], and LHCb [4] Collaborations have published results on Υ(nS) (n = 1, 2, 3) production c√ross sections times dimuon branching fractions in pp collisions at s = 7 TeV as a function of the Υ transverse momentum pT, rapidity y, and polarization [5]
Hadronic production of S-wave bb mesons has been extensively studied for many years
In this Letter we present a measurement of the differential production cross√sections of the three lowest-mass Υ(nS) states in pp collisions at s = 7 TeV up to pT = 100 GeV, reaching higher pT than previous measurements
Summary
At the CERN LHC, the CMS [1,2], ATLAS [3], and LHCb [4] Collaborations have published results on Υ(nS) (n = 1, 2, 3) production c√ross sections times dimuon branching fractions in pp collisions at s = 7 TeV as a function of the Υ transverse momentum pT, rapidity y, and polarization [5]. Neither the ATLAS nor the CMS results show any statistically significant rapidity dependence of the cross section in the central region. We measure the pT dependence of the Υ(nS) differential cross section times the branching fraction to μ+μ− using the 2011 data set, corresponding to an integrated luminosity of 4.9 fb−1. The measured cross sections include feeddown from higher bb excitations
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
