A measurement of the production cross section ratio sigma(chi b2(1P))/sigma(chi b1(1P)) is presented. The chi b1 (1P) and chi b2 (1P) bottomonium states, promptly produced in pp collisions at root s = 8TeV, are detected by the CMS experiment at the CERN LHC through their radiative decays chi b1,2(1P) -> Y(1S) + gamma. The emitted photons are measured through their conversion to e(+) e(-) pairs, whose reconstruction allows the two states to be resolved. The Y(1S) is measured through its decay to two muons. An event sample corresponding to an integrated luminosity of 20.7 fb(-1) is used to measure the cross section ratio in a phase-space region defined by the photon pseudorapidity, vertical bar eta(gamma)vertical bar < 1.0; the Y(1S) rapidity, vertical bar y(Y)vertical bar < 1.5; and the Y(1S) transverse momentum, 7 < p(T)(Y) < 40 GeV. The cross section ratio shows no significant dependence on the.(1S) transverse momentum, with a measured average value of 0.85 +/- 0.07 (stat + syst) +/- 0.08 (BF), where the first uncertainty is the combination of the experimental statistical and systematic uncertainties and the second is from the uncertainty in the ratio of the chi b branching fractions. (C) 2015 CERN for the benefit of the CMS Collaboration. Published by Elsevier B.V.

Khachatryan, V., Sirunyan, A.M., Tumasyan, A., Adam, W., Bergauer, T., Dragicevic, M., et al. (2015). Measurement of the production cross section ratio σ(χb2(1P))/σ(χb1(1P)) in pp collisions at √s=8TeV. PHYSICS LETTERS. SECTION B, 743, 383-402 [10.1016/j.physletb.2015.02.048].

Measurement of the production cross section ratio σ(χb2(1P))/σ(χb1(1P)) in pp collisions at √s=8TeV

CIOCCI, MARIA AGNESE;MESSINEO, ALBERTO MARIA;
2015-01-01

Abstract

A measurement of the production cross section ratio sigma(chi b2(1P))/sigma(chi b1(1P)) is presented. The chi b1 (1P) and chi b2 (1P) bottomonium states, promptly produced in pp collisions at root s = 8TeV, are detected by the CMS experiment at the CERN LHC through their radiative decays chi b1,2(1P) -> Y(1S) + gamma. The emitted photons are measured through their conversion to e(+) e(-) pairs, whose reconstruction allows the two states to be resolved. The Y(1S) is measured through its decay to two muons. An event sample corresponding to an integrated luminosity of 20.7 fb(-1) is used to measure the cross section ratio in a phase-space region defined by the photon pseudorapidity, vertical bar eta(gamma)vertical bar < 1.0; the Y(1S) rapidity, vertical bar y(Y)vertical bar < 1.5; and the Y(1S) transverse momentum, 7 < p(T)(Y) < 40 GeV. The cross section ratio shows no significant dependence on the.(1S) transverse momentum, with a measured average value of 0.85 +/- 0.07 (stat + syst) +/- 0.08 (BF), where the first uncertainty is the combination of the experimental statistical and systematic uncertainties and the second is from the uncertainty in the ratio of the chi b branching fractions. (C) 2015 CERN for the benefit of the CMS Collaboration. Published by Elsevier B.V.
2015
Khachatryan, V., Sirunyan, A.M., Tumasyan, A., Adam, W., Bergauer, T., Dragicevic, M., et al. (2015). Measurement of the production cross section ratio σ(χb2(1P))/σ(χb1(1P)) in pp collisions at √s=8TeV. PHYSICS LETTERS. SECTION B, 743, 383-402 [10.1016/j.physletb.2015.02.048].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/1327850