Forward pi+/- production in p-O2 and p-N2 interactions at 12 GeV/c

TL;DR

This paper reports measurements of charged pion production cross-sections from 12 GeV/c proton interactions with O_2 and N_2, providing data crucial for atmospheric neutrino flux calculations and air shower simulations.

Contribution

It provides the first detailed double-differential cross-section measurements for p--O_2 and p--N_2 interactions at 12 GeV/c, testing the applicability of p--C data for other nuclei.

Findings

Cross-sections measured for p--O_2 and p--N_2 interactions.

Results help reduce uncertainties in atmospheric neutrino flux models.

Data supports or challenges the use of p--C data to predict other nuclei interactions.

Abstract

Measurements of double-differential charged pion production cross-sections in interactions of 12 GeV/c protons on O_2 and N_2 thin targets are presented in the kinematic range 0.5 GeV/c < p_{\pi} < 8 GeV/c and 50 mrad < \theta_{\pi} < 250 mrad (in the laboratory frame) and are compared with p--C results. For p--N_2 (p--O_2) interactions the analysis is performed using 38576 (7522) reconstructed secondary pions. The analysis uses the beam instrumentation and the forward spectrometer of the HARP experiment at CERN PS. The measured cross-sections have a direct impact on the precise calculation of atmospheric neutrino fluxes and on the improved reliability of extensive air shower simulations by reducing the uncertainties of hadronic interaction models in the low energy range. In particular, the present results allow the common hypothesis that p--C data can be used to predict the p--N_2 and p--O_2 pion production cross-sections to be tested.