In-medium spectral change of omega meson as a probe of QCD four-quark condensate


In-medium spectral change of omega meson as a probe of QCD four-quark condensate

Zschocke, S.; Pavlenko, O. P.; Kämpfer, B.

Within QCD sum rules at finite baryon density we show the crucial role of four-quark condensates, such as ‹(overline{q} γμλaq)2n, for the in-medium modification of the ωmeson spectral function. In particular, such a global property as the sign of the in-medium omega meson mass shift is found to be governed by a parameter which describes the strength of the density dependence of the four-quark condensate beyond mean-field approximation.
To study self-consistently the broadening of the omega meson resonance we employ a hadron spectral function based on the omega meson propagator delivered by a effective chiral Lagrangian. Measurements of the ωmeson spectral change in heavy-ion collisions with the HADES detector can reveal the yet unknown density dependence of the four-quark condensate.

Keywords: in-medium properties of hadrons; QCD sum rules; spectral function

Permalink: https://www.hzdr.de/publications/Publ-5184
Publ.-Id: 5184