In-medium modification of P-wave charmonia from QCD sum rules

TL;DR

This paper studies how the masses and widths of P-wave charmonia, specifically $ ext{chi}_{c0}$ and $ ext{chi}_{c1}$, are affected by hot gluonic and nuclear matter near the QCD critical temperature using QCD sum rules, highlighting significant in-medium modifications.

Contribution

It introduces the first inclusion of twist-2 terms for P-wave charmonia in QCD sum rule calculations of in-medium effects, extending previous work on S-wave states.

Findings

Larger mass shifts for P-wave states compared to S-wave states.

Significant width broadening in hot and nuclear medium.

Critical phenomena near $T_c$ can be probed through these modifications.

Abstract

We investigate the changes of the masses and widths of $\chi_{c0}$ and $\chi_{c1}$ in hot gluonic matter near $T_c$ and in nuclear medium using QCD sum rules. As in the previous works for the $J/\psi$ and $\eta_c$, in-medium effects are incorporated through the changes of gluon condensates. Twist-2 terms for the $^3 P_0 (\chi_{c0})$ and $^3 P_1 (\chi_{c1})$ are also included for the first time. The results show that larger mass shifts and width broadenings take place as compared to the $S$-wave states. As the critical change take place near $T_c$, related measurements can reveal critical phenomenon in QCD.