Nucleon-to-Delta transition form factors in chiral effective field theory using the complex-mass scheme

We calculate the form factors of the electromagnetic nucleon-to-$Delta$-resonance transition to third chiral order in manifestly Lorentz-invariant chiral effective field theory. For the purpose of generating a systematic power counting, the complex-mass scheme is applied in combination with the small-scale expansion. We fit the results to available empirical data.