Nuclear many-body theory for the study of QCD sum rules in matter

Journal Article · Thu Jun 01 04:00:00 EDT 1995 · Physical Review, C

DOI:https://doi.org/10.1103/PhysRevC.51.3372· OSTI ID:55179

Celenza, L S; Shakin, C M; Sun, W; Szweda, J ^[1]

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1. Department of Physics and Center for Nuclear Theory, Brooklyn College of the City University of New York, Brooklyn, New York 11210 (United States)

We discuss the calculation of QCD sum rules for hadrons in matter from the point of view of nuclear many-body theory and treat the sum rule for the rho meson as an example. We describe the factorization approximation that is used to calculate four-quark condensates in vacuum and in matter and discuss the corrections to that approximation in some detail. In the case of the rho meson, we find that corrections to the factorization approximation in matter can vary from about 10 to 40 percent depending upon the model used to describe the nucleon. If the nucleon is considered to be composed of a quark coupled to a scalar ({ital T}=0) diquark, the corrections are significant, while, if the quark is coupled to an axial-vector ({ital T}=1) diquark, the corrections are small. The physical nucleon may be taken to have equal scalar and axial-vector diquark components. In that case, corrections of about 20 percent are found for the density-dependent part of the vector-isovector polarization tensor. More precise estimates require a more detailed picture of nucleon structure than that considered here. In a previous work we discussed the corrections to the factorization approximate for the nucleon-nucleon correlator evaluated in nuclear matter. The corrections we calculated served to eliminate a problematic density dependence of the four-quark condensates that arose when using the factorization approximation in matter. However, our study provided a successful analysis only when the interpolating field advocated by Ioffe was used. The situation in the case of sum rules for the vector-isovector polarization tensor is subject to fewer uncertainties, since the choice of the current is unique. We find that, while the corrections we calculate for the density dependence of the four-quark condensates are not small, they lead to only very small modifications in the predicted density dependence of the rho mass.

• OSTI ID: 55179
• Journal Information: Physical Review, C, Journal Name: Physical Review, C Journal Issue: 6 Vol. 51; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
CONDENSATES
CORRECTIONS
FACTORIZATION
HADRONS
MANY-BODY PROBLEM
MATTER
POLARIZATION
QUANTUM CHROMODYNAMICS
QUARKS
RHO-770 MESONS
SUM RULES