Nucleon-nucleon potential: Relativistic and heavy Baryon formalism

We present here preliminary results of our study of the two-pion component of the NN potential using covariant chiral symmetry restricted to just pion and nucleon degrees of freedom. In a first step we perform the full calculation using feynman parametrizations and restore the results obtained in reference [3]. Next we use several relations among feynman integrals and try to rewrite the amplitude evidencing the correct chiral scale. Finally we expand the integrals and compare it with the heavy baryon approach [5].