Initial results from the HARP experiment at CERN

Initial results on particle yields obtained by the HARP experiment are presented. The measurements correspond to proton-nucleus collisions at beam energies of 12.9 GeV/c and for a thin Al target of 5% interacion legth. The angular range considered is between 10 and 250 mrad. This results are the first step in the upcoming measurement of the forward production cross-section for the same target and beam energy, relevant for the calculation of the far-to-near ratio of the K2K experiment.