Measurement of prompt hadron production ratios in pp collisions at s√= 0.9 and 7 TeV

Abstract

The charged-particle production ratios p¯/p, K −/K +, π −/π +, (p+p¯)/(π++π−), (K ++K −)/(π ++π −) and (p+p¯)/(K++K−) are measured with the LHCb detector using 0.3 nb−1 of pp collisions delivered by the LHC at s√=0.9 TeV and 1.8 nb−1 at s√=7 TeV. The measurements are performed as a function of transverse momentum p T and pseudorapidity η. The production ratios are compared to the predictions of several Monte Carlo generator settings, none of which are able to describe adequately all observables. The ratio p¯/p is also considered as a function of rapidity loss, Δy≡y beam−y, and is used to constrain models of baryon transport.