QCD sum rules for D and B mesons in nuclear matter

TL;DR

This paper uses QCD sum rules to analyze how the masses of D and B mesons split in nuclear matter, revealing significant density-dependent effects driven by various quark and gluon condensates.

Contribution

It provides a detailed evaluation of D and B meson mass splittings in nuclear matter, incorporating strange quark effects and heavy-quark mass contributions for the first time.

Findings

Mass splitting of D and B mesons increases with nuclear density.

Condensates <q-adjoint q>, <q-adjoint g sigma G q>, and <q-bar q> drive the splitting.

Strange quark condensates have a smaller, opposite effect on Ds mesons.

Abstract

QCD sum rules for D and B mesons embedded in cold nuclear matter are evaluated. We quantify the mass splitting of D - D-bar and B - B-bar mesons as a function of the nuclear matter density; extrapolated to saturation density it is in the order of 60 and 130 MeV driven essentially by the condensates <q-adjoint q>, <q-adjoint g sigma G q> and <q-bar q>. The genuine chiral condensate <q-bar q>, amplified by heavy-quark masses, enters the Borel transformed sum rules for the mass splitting beyond linear density dependence. Including strange quark condensates reveals a umerically smaller and opposite effect for the Ds - Ds-bar mass splitting.