Influence of gauge boson mass on the staggered spin susceptibility
  Based on the study of the linear response of the fermion propagator in the presence of an external scalar field, we calculate the staggered spin susceptibility in the low energy limit in the framework of the Dyson-Schwinger approach. We analyze the effect of a finite gauge boson mass on the staggered spin susceptibility in both Nambu phase and Wigner phase. It is found that the gauge boson mass suppresses the staggered spin susceptibility in Wigner phase. In addition, we try to give an explanation for why the antiferromagnetic spin correlation increases when the doping is lowered. 
Jian-Feng Li, Feng-Yao Hou, Zhu-Fang Cui, Hong-Tao Feng, Yu Jiang,   Hong-Shi Zong
hep-ph