Observation of the hadronic final state charge asymmetry in high Q2 deep-inelastic scattering at HERA

A first measurement is presented of the charge asymmetry in the hadronic final state from the hard interaction in deep-inelastic ep neutral current scattering at HERA. The measurement is performed in the range of negative squared four momentum transfer 100 < Q 2 < 8000 GeV 2. The difference between the event normalised distributions of the scaled momentum, x p, for positively and negatively charged particles, measured in the current region of the Breit frame, is studied together with its evolution as a function of Q. The results are compared to Monte Carlo models at the hadron and parton levels. © 2009 Elsevier B.V.