$ψ'$ Polarization as a test of colour octet quarkonium production

M. Beneke; I. Rothstein

Paper

$ψ'$ Polarization as a test of colour octet quarkonium production

Abstract

We calculate the

corrections to the transverse polarization fraction of

's produced at the Tevatron. If the `

-anomaly' is explained by gluon fragmentation into a colour octet Fock component of the

, the

's should be

transversely polarized at leading order in

, up to spin symmetry breaking long-distance corrections. We find that the short-distance correction to the transverse polarization fraction is a few percent, so that a polarization measurement would provide a reliable test of the colour octet mechanism.