Measurement of ϒ production in pp collisions at [Formula: see text]

Eur Phys J C Part Fields. 2012;72(6):2025. doi: 10.1140/epjc/s10052-012-2025-y. Epub 2012 Jun 7.

Abstract

The production of ϒ(1S), ϒ(2S) and ϒ(3S) mesons in proton-proton collisions at the centre-of-mass energy of [Formula: see text] is studied with the LHCb detector. The analysis is based on a data sample of 25 pb-1 collected at the Large Hadron Collider. The ϒ mesons are reconstructed in the decay mode ϒμ+μ- and the signal yields are extracted from a fit to the μ+μ- invariant mass distributions. The differential production cross-sections times dimuon branching fractions are measured as a function of the ϒ transverse momentum pT and rapidity y, over the range pT <15 GeV/c and 2.0<y<4.5. The cross-sections times branching fractions, integrated over these kinematic ranges, are measured to be [Formula: see text] where the first uncertainty is statistical, the second systematic and the third is due to the unknown polarisation of the three ϒ states.