We study the multiple scattering effects on inclusive particle production in $\mathrm{p}+\mathrm{A}$ and $\gamma +\mathrm{A}$ collisions. Specifically, we concentrate on the region where the parton momentum fraction in the nucleus $x\sim \mathcal{O}(1)$ and incoherent multiple interactions are relevant. By taking into account both initial-state and final-state double scattering, we derive the nuclear size-enhanced power corrections to the differential cross section for single inclusive hadron production in $\mathrm{p}+\mathrm{A}$ and $\gamma +\mathrm{A}$ reactions, and for prompt photon production in $\mathrm{p}+\mathrm{A}$ reactions. We find that the final result can be written in a simple compact form in terms of four-parton correlation functions, in which the second-derivative, first-derivative and nonderivative terms of the correlation distributions share the same hard-scattering functions. We expect our result to be especially relevant for understanding the nuclear modification of particle production in the backward rapidity regions in $\mathrm{p}+\mathrm{A}$ and $\mathrm{e}+\mathrm{A}$ collisions.

• Received 18 July 2013

DOI:https://doi.org/10.1103/PhysRevD.88.054010