Phase structure of the quartic-cubic generalized two dimensional Yang Mills U(N) on the sphere

The large-N behavior of the quartic-cubic generalized two dimensional Yang Mills U(N) on the sphere is investigated, for small cubic couplings. It is shown that single transition at the critical area which is present for the quartic model, is split into two transitions, both of them are third order. the phase diagram of the system for small cubic couplings is obtained.