Comparison of energy dependence of transverse momentum of dimuons produced in ρN and π^-N interactions with quantum-chromodynamic predictions

Abstract

We have analyzed the dependence of the average transverse momentum squared <ρ_τ²> of dimuons produced in ρN and π^-N interactions on s, the square of the center-of-mass energy. The presently available data indicate a linear increase of <ρT²> with s in both reactions, with the rate of increase being approximately twice as large in the π^-N reaction for Ms=0.28 as in the ρN reaction for Ms=0.22. The value of <ρT²> extrapolated to s=0, which is interpreted as the intrinsic <κT²> of the π^- and ρ constituents, is the same within errors for both reactions. First-order QCD consistently predicts a lower <ρT²> at all s than is observed in the data.