Measurement of the D-+/- production asymmetry in 7 TeV pp collisions

The asymmetry in the production cross-section sigma of D-+/- mesons, Ap = sigma(D+)-sigma(D-)/sigma(D+)-sigma(D-), is measured in bins of pseudorapidity eta and transverse momentum pi within the acceptance of the LHCb detector. The result is obtained with a sample of D+ -> K-s(0)pi(+) decays corresponding to an integrated luminosity of 1.0 fb(-1), collected in pp collisions at a centre of mass energy of 7 TeV at the Large Hadron Collider. When integrated over the kinematic range 2.0 < p(T) < 18.0 GeV/c and 2.20 < eta < 4.75, the production asymmetry is Ap = (-0.96 +/- 0.26 +/- 0.18)%. The uncertainties quoted are statistical and systematic, respectively. The result assumes that any direct CP violation in the D+ -> K-s(0)pi(+) decay is negligible. No significant dependence on eta or p(T) is observed. (C) 2012 CERN. Published by Elsevier B.V. All rights reserved.