Observation of chi_c and chi_b nuclear suppression via dilepton polarization measurements

TL;DR

This paper proposes using vector quarkonia polarization measurements from dilepton events as an indirect method to study the suppression of chi_c and chi_b states in heavy-ion collisions, offering insights into quarkonium suppression mechanisms.

Contribution

It introduces a novel polarization-based approach to investigate quarkonium suppression in environments where direct photon detection is challenging.

Findings

Polarization changes indicate nuclear dissociation patterns.

Method can distinguish suppression of different quarkonium states.

Supports quarkonium sequential suppression hypothesis.

Abstract

We demonstrate that it is possible to use the polarization of vector quarkonia, measured from dilepton event samples, as an instrument to study the suppression of chi_c and chi_b in heavy-ion collisions, where a direct determination of signal yields involving the identification of low-energy photons is essentially impossible. A change of the observed J/psi and Upsilon(1S) polarizations from proton-proton to central nucleus-nucleus collisions would directly reflect differences in the nuclear dissociation patterns of S and P states and may provide a strong indication for quarkonium sequential suppression in the quark-gluon plasma.