Measurement of the Υ(1S), Υ(2S), and Υ(3S) Polarizations in pp Collisions at √s=7 TeV
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. Show more
Permanent link
https://doi.org/10.3929/ethz-b-000064583Publication status
publishedExternal links
Journal / series
Physical Review LettersVolume
Pages / Article No.
Publisher
American Physical SocietyOrganisational unit
03381 - Pauss, Felicitas (emeritus)
03904 - Wallny, Rainer / Wallny, Rainer
08803 - Grab, Christoph (Tit.Prof.)
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