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Pion-nucleon Sigma Term in the Global Color Model of QCD

Lei Chang·Yu-xin Liu·Hua Guo
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Abstract

We study the pion-nucleon sigma term in vacuum and in nuclear matter in the framework of global color model of QCD. With the effective gluon propagator being taken as the $δ$-function in momentum space of Munczek-Nomirovsky model, we estimate that the sigma term at chiral limit in the vacuum is 9/2 times the current quark mass and it decreases with the nuclear matter density. With the presently obtained in-medium pion-nucleon sigma term, we study the in-medium chiral quark condensate and obtain a reasonable variation behavior against the nuclear matter density.

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Lei Chang, Yu-xin Liu, Hua Guo. 2005-11-25. Pion-nucleon Sigma Term in the Global Color Model of QCD. https://doi.org/10.1103/physrevd.72.094023

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