First determination of vector and tensor couplings from polarized πDelta photoproduction

The couplings between hadrons encode the dynamics of quantum chromodynamics. While many couplings can be calculated from decay widths, in some cases the decays are kinematically forbidden and hence are not directly accessible. We use a Regge framework to determine these couplings from high-energy polarized scattering processes. We apply this to the $\pi\Delta$ photoproduction that was recently studied at GlueX and provide the first determination of the complete set of $N\Delta$ couplings to $\rho$, $b_1$, and $a_2$.