The polarizations of the Υ(1S), Υ(2S), and Υ(3S) mesons are measured in proton-proton collisions at √s=7  TeV, using a data sample of Υ(nS)→μ+μ− decays collected by the CMS experiment, corresponding to an integrated luminosity of 4.9  fb−1. The dimuon decay angular distributions are analyzed in three different polarization frames. The polarization parameters λϑ, λφ, and λϑφ, as well as the frame-invariant quantity ˜λ, are presented as a function of the Υ(nS) transverse momentum between 10 and 50 GeV, in the rapidity ranges |y|<0.6 and 0.6<|y|<1.2. No evidence of large transverse or longitudinal polarizations is seen in the explored kinematic region.

Measurement of the Υ(1S), Υ(2S), and Υ(3S) Polarizations in pp Collisions at √s 7 TeV

L. Bianchini;MARTINI, LUCA;MESSINEO, ALBERTO MARIA;RIZZI, ANDREA;TONELLI, GUIDO EMILIO;A. C. Marini;
2013-01-01

Abstract

The polarizations of the Υ(1S), Υ(2S), and Υ(3S) mesons are measured in proton-proton collisions at √s=7  TeV, using a data sample of Υ(nS)→μ+μ− decays collected by the CMS experiment, corresponding to an integrated luminosity of 4.9  fb−1. The dimuon decay angular distributions are analyzed in three different polarization frames. The polarization parameters λϑ, λφ, and λϑφ, as well as the frame-invariant quantity ˜λ, are presented as a function of the Υ(nS) transverse momentum between 10 and 50 GeV, in the rapidity ranges |y|<0.6 and 0.6<|y|<1.2. No evidence of large transverse or longitudinal polarizations is seen in the explored kinematic region.
2013
Chatrchyan, S.; Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Aguilo, E.; Bergauer, T.; Dragicevic, M.; Eroe, J.; Fabjan, C.; Friedl, M.; ...espandi
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11568/581738
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