Jul 4 – 11, 2012
Melbourne Convention and Exhibition Centre
Australia/Melbourne timezone
ICHEP2012 - 36th International Conference for High Energy Physics

Measurements of Y(nS) polarization with the CMS experiment

Jul 7, 2012, 2:45 PM
Room 217 (Melbourne Convention and Exhibition Centre)

Room 217

Melbourne Convention and Exhibition Centre

Melbourne Australia
Parallel Sessions Track 6. QCD, Jets, Parton Distributions Room 217 - Education & Outreach - QCD, Jet, Parton Distributions - TR15&6


Mr Valentin Knunz (Austrian Academy of Sciences (AT))


The polarizations of the Upsilon(1S), Upsilon(2S) and Upsilon(3S) mesons produced in proton-proton collisions at = 7 TeV are measured using a data sample collected with the CMS detector at the LHC, corresponding to an integrated luminosity of around 5 fb^{-1}. The measurements are based on the analysis of the dimuon decay angular distributions, analyzed in three different polarization frames, and are presented as a function of the Upsilon transverse momentum, in two rapidity ranges. The measurement of the polarization parameters, lambda_theta, lambda_phi and lambda_{theta phi} is complemented by the determination of the frame-invariant quantity lambda_tilde, which provides a very useful intrinsic test of the reliability of the whole analysis chain and supplementary physical information.

Primary author

Mr Valentin Knunz (Austrian Academy of Sciences (AT))

Presentation materials