Inclusive correlations between photons and charged pions

Theoretical predictions are presented for high-energy ${\pi }^c{\pi }^c$, ${\pi }^c\gamma$, and $\gamma \gamma$ correlations, where ${\pi }^c$ is a charged pion. Photons are assumed to come from ${\pi }^0$ decay. The predictions are based on the kinematics of this decay as well as the isospin constraints for $\pi \pi$ correlations. Apart from terms of order $s^{\frac{-1\mathrm{}}{2}}$, the $\gamma \gamma$ rapidity correlation corrected for $\gamma$ pairs from the same ${\pi }^0$ is expected to be well approximated by twice the ${\pi }^c{\pi }^c$ correlation minus the ${\pi }^c\gamma$ correlation. Explicit calculations are presented for the central region. Generalizations to higher correlations and other processes are discussed.