Measurement of the light component (p+He) energy spectrum with the DAMPE space mission

Abstract

The DArk Matter Particle Explorer (DAMPE) is a space-based particle detector launched in a Sun-synchronous orbit on December 17$\mathrm{^{th}}$, 2015 from the Jiuquan Satellite Launch Center, in China. It has been taking data very smoothly for more than 5 years. Science goals of the DAMPE mission include the study of the electron-positron energy spectrum, the study of galactic cosmic-rays, gamma-ray astronomy, and indirect dark matter search. Performing precise measurements of light elements in space, the most abundant components of cosmic radiation, is necessary to address major problems in galactic cosmic ray acceleration and propagation mechanisms. Selecting a combined proton and helium sample (instead of proton or helium alone) allows larger efficiency and purity, also minimizing systematic effects in the reconstruction of the energy spectrum, due to possible cross-contaminations. The use of looser analysis cuts allows collecting larger statistics thus extending the covered energy range and providing a link between direct and indirect cosmic-ray measurements. The measurement of the p+He energy spectrum up to $\sim$ 150 TeV will be presented, along with a discussion on the features of the spectrum and a comparison with other experimental results.