Measurements of the angular distributions of muons from Υ decays in pp collisions at sqrt[s] = 1.96  TeV.

The angular distributions of muons from Υ(1S,2S,3S) → μ+ μ- decays are measured using data from pp collisions at sqrt[s] = 1.96  TeV corresponding to an integrated luminosity of 6.7  fb(-1) and collected with the CDF II detector at the Fermilab Tevatron. This analysis is the first to report the full...

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Bibliographic Details
Main Authors: Aaltonen, T, Álvarez González, B, Amerio, S, Amidei, D, Anastassov, A, Annovi, A, Antos, J, Apollinari, G, Appel, J, Arisawa, T, Artikov, A, Asaadi, J, Ashmanskas, W, Auerbach, B, Aurisano, A, Azfar, F, Badgett, W, Bae, T, Barbaro-Galtieri, A, Barnes, V, Barnett, B, Barria, P, Bartos, P, Bauce, M, Bedeschi, F
Format: Journal article
Language:English
Published: 2012
Description
Summary:The angular distributions of muons from Υ(1S,2S,3S) → μ+ μ- decays are measured using data from pp collisions at sqrt[s] = 1.96  TeV corresponding to an integrated luminosity of 6.7  fb(-1) and collected with the CDF II detector at the Fermilab Tevatron. This analysis is the first to report the full angular distributions as functions of transverse momentum p(T) for Υ mesons in both the Collins-Soper and s-channel helicity frames. This is also the first measurement of the spin alignment of Υ(3S) mesons. Within the kinematic range of Υ rapidity |y|<0.6 and p(T) up to 40  GeV/c, the angular distributions are found to be nearly isotropic.