  The boundary of the first order chiral phase transition region is studied in
the m_pi-m_K-mu_B space using the one-loop optimized perturbation theory for
the resummation of the perturbative series. Chiral perturbation theory for
mesons and baryons is used for the T=0 parametrization of the model. The
surface of second order transition points bends with increasing mu_B towards
the physical point of the m_pi-m_K mass plane allowing for the existence of the
critical end point in the mu_B-T plane at the physical point. The location and
scaling region of the CEP is explored.
