Measurements of the $\\Upsilon$(1S), $\\Upsilon$(2S), and $\\Upsilon$(3S) differential cross sections in pp collisions at $\\sqrt{s} =$ 7 TeV
Journal
Physics Letters
Journal Volume
B749
Pages
14-34
Date Issued
2015-01
Author(s)
Abstract
Differential cross sections as a function of transverse momentum p T are presented for the production of (nS) (n = 1, 2, 3) states decaying into a pair of muons. Data corresponding to an integrated luminosity of 4.9 fb -1 in pp collisions at s = 7 TeV 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 < p T < 100 GeV. The measurements show a transition from an exponential to a power-law behavior at p T 20 GeV for the three states. Above that transition, the (3S) spectrum is significantly harder than that of the (1S). The ratios of the (3S) and (2S) differential cross sections to the (1S) cross section show a rise as p T increases at low p T , then become flatter at higher p T .
Type
journal article