Results from a Pilot Study on the Measurement of Nuclear Fragmentation with NA61/SHINE at the CERN SPS: ¹¹C Production in C+p Interactions at 13.5 AGeV/c

Abstract

We report the analysis of data taken during a pilot run in 2018 to study the feasibility of nuclear fragmentation measurements with the NA61/SHINE experiment at the CERN SPS. These nuclear reactions are important for the interpretation of secondary cosmic-ray nuclei production (Li, Be, and B) in the Galaxy. The pilot data were taken with 12C projectiles at a beam momentum of 13.5 AGeV/c and two fixed targets, polyethylene (C2H4) and graphite. The specific focus here is the measurement of total Boron (10B and 11B) production cross section in C+p interactions at 13.5 AGeV/c. The cosmic-ray nucleus 11C is termed a ‘Ghost nucleus’ on account of its short lifetime compared to the usual cosmic-ray diffusion time in the Galaxy and it ultimately decays to Boron as, 11C → 11B + β+. Therefore, precise knowledge of the production cross section of 11C is very relevant for the understanding of Boron production in the Galaxy. We present a preliminary measurement of the fragmentation cross section of C + p → 11C, which, together with our previously reported B-production cross section, provides a new constraint on boron production in the Galaxy in the high-energy range relevant for modern space based cosmic-ray experiments like AMS-02.