Neutron conversion–diffusion: a new model for structured short gamma-ray burst jets compatible with GRB 170817

We present a generic theoretical model for the structuring of relativistic jet propagating through ejecta binary neutron star merger event, introducing effects conversion-diffusion, which provides baryon flux transversely from towards axis. This results naturally in an increased load structure outer with approximate isotropic energy distribution $E_{iso}(\theta) \propto \theta^{-4}$, is compatible first gravitational wave and short gamma-ray burst event GW170817/GRB 170817A observed at off-axis angle jet.