Isospin violations in large P_T pion inclusive processes in perturbative quantum chromodynamics

Abstract

We investigate the asymmetries arising due to electromagnetic interactions in large P_T pion inclusive processes. The hardqcd processes that contribute to such asymmetries are q + g → q + γ , q + q̅ → g + γ etc. which are suspected to be substantial, as indicated by the QCD predictions for a significant and increasing γ/π° ratio at large P_T. We calculate the expected isospin related asymmetries and propose tests that might detect them. Our estimates indicate that the effects are much smaller than may be naively expected. We also observe a remarkable scaling of asymmetries in the variable P_T/(s)^1/2.