Heavy elements synthesized in an accretion disk around a black hole associated with gamma-ray bursts

We examine nucleosynthesis inside an accretion disk with accretion rates 0.01 - 1M_⊙ s^-1 associated with gamma-ray bursts. The black hole mass is fixed to be 3M_⊙. The chemical composition of accreting gas far from the black hole is taken to be that of an oxygen-rich layer of a massive star before the collapse. The disk consists of five layers characterized by dominant elements: ¹⁶O, ²⁸Si, ⁵⁴Fe (and ⁵⁶Ni), ⁴He, and nucleons. As the accretion rate increases, the individual layers shift outwards with keeping the overall profiles of composition. A similar situation may be realized in an accretion disk around an intermediate mass black hole produced in a collapsing Population III supermassive star.