Multiplicities of charged pions and unidentified charged hadrons from   deep-inelastic scattering of muons off an isoscalar target
  Multiplicities of charged pions and unidentified hadrons produced in deep-inelastic scattering were measured in bins of the Bjorken scaling variable $x$, the relative virtual-photon energy $y$ and the relative hadron energy $z$. Data were obtained by the COMPASS Collaboration using a 160 GeV muon beam and an isoscalar target ($^6$LiD). They cover the kinematic domain in the photon virtuality $Q^2$ > 1(GeV/c$)^2$, $0.004 < x < 0.4$, $0.2 < z < 0.85$ and $0.1 < y < 0.7$. In addition, a leading-order pQCD analysis was performed using the pion multiplicity results to extract quark fragmentation functions. 
C. Adolph, J. Agarwala, M. Aghasyan, R. Akhunzyanov, M.G. Alexeev,   G.D. Alexeev, A. Amoroso, V. Andrieux, N.V. Anfimov, V....
hep-ex nucl-ex