Measurement of the Inclusive Upsilon production cross section in pp collisions at sqrt(s)=7 TeV

TL;DR

This paper reports the measurement of Upsilon(1S) production cross sections in proton-proton collisions at 7 TeV using CMS data, including differential cross sections and polarization effects, providing key insights into quarkonium production.

Contribution

The study presents the first measurement of Upsilon(1S), Upsilon(2S), and Upsilon(3S) cross sections at 7 TeV with detailed polarization considerations and differential distributions.

Findings

Measured Upsilon(1S) cross section as 7.37 nb with uncertainties.

Differential cross sections as functions of transverse momentum and rapidity.

Cross section varies by about 20% with different polarization assumptions.

Abstract

The Upsilon production cross section in proton-proton collisions at sqrt(s) = 7 TeV is measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of 3.1 +/- 0.3 inverse picobarns. Integrated over the rapidity range |y|<2, we find the product of the Upsilon(1S) production cross section and branching fraction to dimuons to be sigma(pp to Upsilon(1S) X) B(Upsilon(1S) to mu+ mu-) = 7.37 +/- 0.13^{+0.61}_{-0.42}\pm 0.81 nb, where the first uncertainty is statistical, the second is systematic, and the third is associated with the estimation of the integrated luminosity of the data sample. This cross section is obtained assuming unpolarized Upsilon(1S) production. If the Upsilon(1S) production polarization is fully transverse or fully longitudinal the cross section changes by about 20%. We also report the measurement of the Upsilon(1S), Upsilon(2S), and Upsilon(3S) differential cross sections as a function of transverse momentum and rapidity.