Parametrization of transition energy-momentum tensor form factors

Abstract

While the Lorentz structures of the N→Δ transition matrix element of the vector current are well-known, that of the symmetric energy-momentum tensor current is unknown. In this letter, we first reproduce the Lorentz structures of the 12±→12±, 12∓→12±, and 12∓→32± transition matrix elements of the vector current. We also repeat the parametrizations of the symmetric energy-momentum tensor current for the 12±→12± and 12∓→12± transitions. We then consider both 12±→32± and 12∓→32± matrix elements of the symmetric energy-momentum tensor current (say, N→Δ transition) for the first time. We found that there are five independent conserved and four independent non-conserved energy-momentum tensor form factors.