Polarizations of J/psi and psi(2S) Mesons Produced in ppbar Collisions at 1.96 TeV

CDF Collaboration

Paper

Polarizations of J/psi and psi(2S) Mesons Produced in ppbar Collisions at 1.96 TeV

Abstract

We have measured the polarizations of

and

mesons as functions of their transverse momentum

when they are produced promptly in the rapidity range

with

. The analysis is performed using a data sample with an integrated luminosity of about

collected by the CDF II detector. For both vector mesons, we find that the polarizations become increasingly longitudinal as

increases from 5 to

. These results are compared to the predictions of nonrelativistic quantum chromodynamics and other contemporary models. The effective polarizations of

and

mesons from

-hadron decays are also reported.