Strange particle production in proton-carbon interactions at 31 GeV/c

Abstract

Spectra of positively charged kaons in p+C interactions at 31 GeV/c have been measured with the NA61/SHINE spectrometer at CERN SPS. The analysis is performed on the dataset collected during the 2007 pilot run (about 678×103 events). The target is a 2 cm long graphite specimen (4% of a nuclear interaction length λI). Charged pion spectra have been already measured with the same dataset [1]. Pion and kaon differential production cross sections are required to improve predictions of the neutrino flux for the T2K long baseline neutrino oscillation experiment in Japan. The knowledge of kaon production is especially important for the precise prediction of the intrinsic electron neutrino component of the T2K beam. The results are presented as a function of laboratory momentum in 2 intervals of the laboratory polar angle covering the range from 20 up to 240 mrad. Kaon spectra as well as K+/π+ ratios are compared with predictions of several hadron production models. In addition, first results from the analysis of the high statistics 2009 data taking are shown.