Defining medium-specific condensates in QCD sum rules for $D$ and $B$ mesons

TL;DR

This paper introduces a method to decompose operators in QCD sum rules for $D$ and $B$ mesons, enabling the identification of medium-specific condensates and potential chiral restoration indicators in strongly interacting environments.

Contribution

The authors develop a procedure to separate vacuum and medium-specific parts of operators, clarifying the role of higher-dimension condensates in QCD sum rules for heavy mesons.

Findings

Defined medium-specific condensates with vanishing vacuum coefficients.

Identified potential order parameters for chiral restoration.

Enhanced understanding of operator decomposition in QCD sum rules.

Abstract

QCD sum rules for $D$ and $B$ mesons in a strongly interacting environment require the decomposition of Gibbs averaged operators related to tensor structures. We present a procedure to decompose these operators into vacuum and medium-specific parts, thus defining plain medium-specific condensates with coefficients vanishing in vacuum. Our decomposition allows for an identification of potential elements of order parameters for chiral restoration, in particular for higher mass-dimension quark-condensates which would be masked otherwise if operators with uncontracted Lorentz indices would be linked to DIS amplitudes.