Electromagnetic transition form factors of the Roper resonance in   effective field theory
  We analyze the form factors of the electromagnetic nucleon-to-Roper-resonance transition in the framework of low-energy effective field theory. A systematic power-counting procedure is generated by applying the complex-mass scheme. Within this power counting we calculate the form factors to next-to-next-to-leading order and fit the results to empirical data. 
T. Bauer, S. Scherer, L. Tiator
nucl-th hep-ph nucl-ex