Production of Two Pions Induced by Neutrinos
  We study the threshold production of two pions induced by neutrinos in nucleon targets. The contribution of nucleon pole, pion and contact terms is calculated using a chiral Lagrangian. The contribution of the Roper resonance, neglected in earlier studies, has also been taken into account. 
M. Valverde, J. Nieves, E. Hern\'andez, S.K. Singh, M.J. Vicente Vacas