Probing Heavy Quarkonium Production Mechnism: $\chi_c$ polarization

TL;DR

This paper investigates the polarization of $$ heavy quarkonium in hadroproduction to test the color-octet mechanism in nonrelativistic QCD, aiming to clarify its role in quarkonium production.

Contribution

It proposes using $$ polarization measurements as a sensitive test for the color-octet mechanism in heavy quarkonium production.

Findings

$$ polarization can distinguish between different production mechanisms.

Polarization measurements can confirm or refute the color-octet contribution.

The study highlights the importance of polarization as an observable in QCD tests.

Abstract

The necessicity of the color-octet mechanism in describing heavy quarkonium production is a longstanding puzzle. Compared to the yields of heavy quarkonium, its polarizations should be a sensitive observable to pin down the color-octet contributions. In this talk, I will focus on the $\chi_c$ polarization in hadroproduction processes, which may provide a unique test for the color-octet mechanism in nonrelativistic QCD.