Measurement of J/Psi and Psi(2S) Polarization in ppbar Collisions at sqrt(s) = 1.8 TeV

TL;DR

This paper reports measurements of the polarization states of J/Psi and Psi(2S) mesons produced in proton-antiproton collisions at 1.8 TeV, revealing no significant polarization at high transverse momentum.

Contribution

First measurement of J/Psi and Psi(2S) polarization in par{p} collisions at Tevatron energies, isolating prompt production from B-hadron decay contributions.

Findings

No significant polarization observed for P_T  12 GeV/c

Data collected at CDF during 1992-95

Kinematic range 4 < P_T < 20 GeV/c, |y| < 0.6

Abstract

We have measured the polarization of J/Psi and Psi(2S) mesons produced in p\bar{p} collisions at \sqrt{s} = 1.8 TeV, using data collected at CDF during 1992-95. The polarization of promptly produced J/Psi [Psi(2S)] mesons is isolated from those produced in B-hadron decay, and measured over the kinematic range 4[5.5] < P_T < 20 GeV/c and |y| < 0.6. For P_T \gessim 12 GeV/c we do not observe significant polarization in the prompt component.