Polarizations of J/psi and psi(2S) mesons produced in pp collisions at square root s = 1.96 TeV.

Journal article

We have measured the polarizations of J/psi and psi(2S) mesons as functions of their transverse momentum p(T) when they are produced promptly in the rapidity range |y| < 0.6 with p(T) > or =5 GeV/c. The analysis is performed using a data sample with an integrated luminosity of about 800 pb(-1) collected by the CDF II detector. For both vector mesons, we find that the polarizations become increasingly longitudinal as p(T) increases from 5 to 30 GeV/c. These results are compared to the predictions of nonrelativistic quantum chromodynamics and other contemporary models. The effective polarizations of J/psi and psi(2S) mesons from B-hadron decays are also reported.

Authors: Abulencia, A; Adelman, J; Affolder, T; Akimoto, T; Albrow, MG

• Journal: Physical Review Letters
• Volume: 99
• Issue: 13
• Pages: 132001
• Publication date: 2007-09-01
• DOI: 10.1103/physrevlett.99.132001
• EISSN: 1079-7114
• ISSN: 0031-9007
• Language: English
• Keywords: CDF Collaboration