Single Inclusive Hadron Production in DIS at Small $x$: Next to Leading Order Corrections

We calculate the one-loop corrections to single inclusive hadron production in Deep Inelastic Scattering (DIS) at small $x$ in the forward rapidity region using the Color Glass Condensate formalism. We show that the divergent parts of the next to leading order (NLO) corrections either cancel among each other or lead to $x$ (rapidity) evolution of the leading order (LO) dipole cross section according to the JIMWLK evolution equation and DGLAP evolution of the parton-hadron fragmentation function. The remaining finite parts constitute the NLO (${\alpha }_s$) corrections to the LO single inclusive hadron production cross section in DIS at small $x$.