New QCD Sum Rules for Nucleons in Nuclear Matter

Abstract

Two new QCD sum rules for nucleons in nuclear matter are obtained from a mixed correlator of spin-1/2 and spin-3/2 interpolating fields. These new sum rules, which are insensitive to the poorly known four-quark condensates, provide additional information on the nucleon scalar self-energy. These new sum rules are analyzed along with previous spin-1/2 interpolator-based sum rules which are also insensitive to the poorly known four-quark condensates. The analysis indicates consistency with the expectations of relativistic nuclear phenomenology at nuclear matter saturation density. However, a weaker density dependence near saturation is suggested. Using previous estimates of in-medium condensate uncertainties, we find $M^{\ast }=0.64_{-0.09}^{+0.13}$ GeV and ${\Sigma }_v=0.29_{-0.10}^{+0.06}$ GeV at nuclear matter saturation density.

Comments: 10 page RevTeX Manuscript with embedded figures. Revised manuscript accepted for publication. This and related papers may also be obtained from http://www.phys.washington.edu/~derek/Publications.html