1302.4994 (Piyabut Burikham et al.)

Chiral symmetry breaking from two-loop effective potential of the
holographic non-local NJL model    [PDF]

Piyabut Burikham, Daris Samart, Suppiya Siranan

We calculate the two-loop effective potential of the non-local NJL model derived from the Sakai-Sugimoto model in string theory. In contrast to conventional NJL with 4-fermion contact interaction, the chiral symmetry was previously found to be dynamically broken for arbitrary weak coupling at the one-loop level. We calculate the one and two-loop contribution to the effective potential of the non-local NJL model and found that the two-loop contribution is less than 50% of the one-loop. The chiral symmetry breaking therefore persists for arbitrary weak coupling.

View original: http://arxiv.org/abs/1302.4994