Spontaneous symmetry breaking of SO(2N) in Gross-Neveu theory from 2+ε expansion
(i)--(iii). Before becoming equal to the Gaussian fixed point at N f =1, (ii) remains critical for all values of N f > N ST f , c ( N )≈0.56+1.48 N + ( ϵ ), which compares well with the estimate of previous [...] fermions. Mean-field theory for the SO(2 N ) model predicts, besides the chiral Ising transition at g c 1, a second critical point g c 2 where SO(2 N ) is broken down to SO( N )×SO( N ). A subsequent Wilsonian [...] separately. However, it turns out that (ii) and (iii) lose their criticality when approaching N f =1, suggesting that the transition is first order. In this work, we approach the problem from the lowe …
