Generalized Gross-Neveu model in d dimensions. Cross-over and fermion masses

► An RG equation for a generalized N flavors GN model in d dimensions is established. ► A mechanism for mass generation resulting from a cross-over transition is then derived. ► Close to d=4 for the first time the χSB is described with no reference to bosonization. ► A technique to compute critical exponents for generic d and N is introduced. ► The NJL mechanism is recovered as an approximate solution to our equation.