TY - JOUR
T1 - Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
AU - Abelev, Betty
AU - Adam, J.
AU - Bøggild, Hans
AU - Bearden, Ian
AU - Christensen, Christian Holm
AU - Gulbrandsen, Kristjan Herlache
AU - Gaardhøje, Jens Jørgen
AU - Dalsgaard, Hans Hjersing
AU - Nielsen, Børge Svane
AU - Nygaard, Casper
AU - Søgaard, Carsten
AU - Hansen, Alexander Colliander
PY - 2012/11/1
Y1 - 2012/11/1
N2 - The ALICE experiment at the LHC has studied J/ψ production at midrapidity in pp collisions at √s = 7TeV through its electron pair decay on a data sample corresponding to an integrated luminosity Lint = 5.6 nb-1. The fraction of J/ψ from the decay of long-lived beauty hadrons was determined for J/ψ candidates with transverse momentum pt > 1.3GeV/c and rapidity |y| < 0.9. The cross section for prompt J/ψ mesons, i.e. directly produced J/ψ and prompt decays of heavier charmonium states such as the ψ(2S) and c resonances, is σprompt J/ψ (pt > 1.3 GeV/c, |y| < 0.9) = 8.3+0.8 (stat.)±} 1.1 (syst.) +1.5 -1.4 (syst. pol.) μb. The cross section for the production of b-hadrons decaying to J/ψ with pt > 1.3GeV/c and |y| < 0.9 is σJ/ψ←hB (pt > 1.3 GeV/c, |y| < 0.9) = 1.46±} 0.38 (stat.) +0.26 -0.32 (syst.) μb. The results are compared to QCD model predictions. The shape of the pt and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the bb pair total cross section and dσ/dy at mid-rapidity.
AB - The ALICE experiment at the LHC has studied J/ψ production at midrapidity in pp collisions at √s = 7TeV through its electron pair decay on a data sample corresponding to an integrated luminosity Lint = 5.6 nb-1. The fraction of J/ψ from the decay of long-lived beauty hadrons was determined for J/ψ candidates with transverse momentum pt > 1.3GeV/c and rapidity |y| < 0.9. The cross section for prompt J/ψ mesons, i.e. directly produced J/ψ and prompt decays of heavier charmonium states such as the ψ(2S) and c resonances, is σprompt J/ψ (pt > 1.3 GeV/c, |y| < 0.9) = 8.3+0.8 (stat.)±} 1.1 (syst.) +1.5 -1.4 (syst. pol.) μb. The cross section for the production of b-hadrons decaying to J/ψ with pt > 1.3GeV/c and |y| < 0.9 is σJ/ψ←hB (pt > 1.3 GeV/c, |y| < 0.9) = 1.46±} 0.38 (stat.) +0.26 -0.32 (syst.) μb. The results are compared to QCD model predictions. The shape of the pt and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the bb pair total cross section and dσ/dy at mid-rapidity.
U2 - 10.1007/jhep11(2012)065
DO - 10.1007/jhep11(2012)065
M3 - Journal article
SN - 1126-6708
VL - 2012
SP - 065
JO - Journal of High Energy Physics (Online)
JF - Journal of High Energy Physics (Online)
IS - 11
ER -