Multiplicities of charged pions and kaons from semi-inclusive   deep-inelastic scattering by the proton and the deuteron
  Multiplicities in semi-inclusive deep-inelastic scattering are presented for each charge state of \pi^\pm and K^\pm mesons. The data were collected by the HERMES experiment at the HERA storage ring using 27.6 GeV electron and positron beams incident on a hydrogen or deuterium gas target. The results are presented as a function of the kinematic quantities x_B, Q^2, z, and P_h\perp. They represent a unique data set for identified hadrons that will significantly enhance our understanding of the fragmentation of quarks into final-state hadrons in deep-inelastic scattering. 
HERMES Collaboration: A. Airapetian, N. Akopov, Z. Akopov, E. C.   Aschenauer, W. Augustyniak, R. Avakian, A. Avetissian, E....
hep-ex nucl-ex