A1 Journal article (refereed), original research

ϒ(nS)polarizations versus particle multiplicity in pp collisions at √s=7TeV


Open Access publication

LUT Authors / Editors

Publication Details
Authors: Khachatryan V., Sirunyan A.M., Tumasyan A., Adam W., Asilar E., Bergauer T., Brandstetter J., Brondolin E., Dragicevic M., Erö J., Fabjan C., Flechl M., Friedl M., Frühwirth R., Ghete V.M., Hartl C., Hörmann N., Talvitie J, Tuuva Tuure, The CMS Collaboration
Publication year: 2016
Language: English
Related Journal or Series Information: Physics Letters B
Volume number: 761
Start page: 31
End page: 52
JUFO-Level of this publication: 2
Open Access: Open Access publication

Abstract
The polarizations of the ϒ(1S)ϒ(1S), ϒ(2S)ϒ(2S), and ϒ(3S)ϒ(3S) mesons are measured as a function of the charged particle multiplicity in proton-proton collisions at s=7TeV. The measurements are performed with a dimuon data sample collected in 2011 by the CMS experiment, corresponding to an integrated luminosity of 4.9 fb-1. The results are extracted from the dimuon decay angular distributions, in two ranges of ϒ(nS)ϒ(nS) transverse momentum (10-15 and 15-35 GeV), and in the rapidity interval |y|<1.2|y|<1.2. The results do not show significant changes from low- to high-multiplicity pp collisions, although large uncertainties preclude definite statements in the ϒ(2S)ϒ(2S) and ϒ(3S)ϒ(3S) cases.

Last updated on 2018-19-10 at 08:49