Measurements of $\pi^{\pm}$ differential yields from the surface of the   T2K replica target for incoming 31 GeV/c protons with the NA61/SHINE   spectrometer at the CERN SPS
  Measurements of particle emission from a replica of the T2K 90 cm-long carbon target were performed in the NA61/SHINE experiment at CERN SPS, using data collected during a high-statistics run in 2009. An efficient use of the long-target measurements for neutrino flux predictions in T2K requires dedicated reconstruction and analysis techniques. Fully-corrected differential yields of $\pi^\pm$-mesons from the surface of the T2K replica target for incoming 31 GeV/c protons are presented. A possible strategy to implement these results into the T2K neutrino beam predictions is discussed and the propagation of the uncertainties of these results to the final neutrino flux is performed. 
NA61/SHINE Collaboration: N. Abgrall, A. Aduszkiewicz, M. Ajaz, Y.   Ali, E. Andronov, T. Anti\'ci\'c, N. Antoniou, B. Baata...
hep-ex physics.ins-det