TY - JOUR
T1 - Measurement of upsilon production in 7 TeV pp collisions at ATLAS
AU - Aad, G.
AU - Abajyan, T.
AU - Abbott, B.
AU - Abdallah, J.
AU - Khalek, A.S.
AU - Dam, Mogens
AU - Hansen, Jørgen Beck
AU - Hansen, Peter Henrik
AU - Hansen, John Renner
AU - Hansen, Jørn Dines
AU - Heisterkamp, Simon Johann Franz
AU - Jørgensen, Morten Dam
AU - Boelaert, Nele Maria Philomena
AU - Klinkby, Esben Bryndt
AU - Løvschall-Jensen, Ask Emil
AU - Mehlhase, Sascha
AU - Nilsson, Björn Stefan
AU - Petersen, Troels Christian
AU - Xella, Stefania
PY - 2013/3/4
Y1 - 2013/3/4
N2 - Using 1.8 fb-1 of pp collisions at a center-of-mass energy of 7 TeV recorded by the ATLAS detector at the Large Hadron Collider, we present measurements of the production cross sections of Υ(1S,2S,3S) mesons. Υ mesons are reconstructed using the dimuon decay mode. Total production cross sections for pT<70 GeV and in the rapidity interval |yΥ|<2.25 are measured to be, 8.01±0.02±0.36±0.31 nb, 2.05±0.01±0.12±0.08 nb, and 0.92±0.01±0. 07±0.04 nb, respectively, with uncertainties separated into statistical, systematic, and luminosity measurement effects. In addition, differential cross section times dimuon branching fractions for Υ(1S), Υ(2S), and Υ(3S) as a function of Υ transverse momentum pT and rapidity are presented. These cross sections are obtained assuming unpolarized production. If the production polarization is fully transverse or longitudinal with no azimuthal dependence in the helicity frame, the cross section may vary by approximately ±20%. If a nontrivial azimuthal dependence is considered, integrated cross sections may be significantly enhanced by a factor of 2 or more. We compare our results to several theoretical models of Υ meson production, finding that none provide an accurate description of our data over the full range of Υ transverse momenta accessible with this data set.
AB - Using 1.8 fb-1 of pp collisions at a center-of-mass energy of 7 TeV recorded by the ATLAS detector at the Large Hadron Collider, we present measurements of the production cross sections of Υ(1S,2S,3S) mesons. Υ mesons are reconstructed using the dimuon decay mode. Total production cross sections for pT<70 GeV and in the rapidity interval |yΥ|<2.25 are measured to be, 8.01±0.02±0.36±0.31 nb, 2.05±0.01±0.12±0.08 nb, and 0.92±0.01±0. 07±0.04 nb, respectively, with uncertainties separated into statistical, systematic, and luminosity measurement effects. In addition, differential cross section times dimuon branching fractions for Υ(1S), Υ(2S), and Υ(3S) as a function of Υ transverse momentum pT and rapidity are presented. These cross sections are obtained assuming unpolarized production. If the production polarization is fully transverse or longitudinal with no azimuthal dependence in the helicity frame, the cross section may vary by approximately ±20%. If a nontrivial azimuthal dependence is considered, integrated cross sections may be significantly enhanced by a factor of 2 or more. We compare our results to several theoretical models of Υ meson production, finding that none provide an accurate description of our data over the full range of Υ transverse momenta accessible with this data set.
U2 - 10.1103/PhysRevD.87.052004
DO - 10.1103/PhysRevD.87.052004
M3 - Journal article
SN - 1550-7998
VL - 87
JO - Physical Review D (Particles, Fields, Gravitation and Cosmology)
JF - Physical Review D (Particles, Fields, Gravitation and Cosmology)
IS - 5
M1 - 052004
ER -