Prepotential of N=2 SU(2) Yang-Mills gauge theory coupled with a massive   matter multiplet
  We discuss the N=2 SU(2) Yang-Mills theory coupled with a massive matter in the weak coupling. In particular, we obtain the instanton expansion of its prepotential. Instanton contributions in the mass-less limit are completely reproduced. We study also the double scaling limit of this massive theory and find that the prepotential with instanton corrections in the double scaling limit coincides with that of N=2 SU(2) Yang-Mills theory without matter. 
Y\H{u}ji Ohta