Test of hadronic interaction models via accelerator data

Abstract

At high energy, cosmic rays can only be studied by measuring the extensive air showers they produce in the atmosphere of the Earth. Although the main features of air showers can be understood within a simple model of successive interactions, detailed simulations and a realistic description of particle production are needed to calculate observables relevant to air shower experiments. Currently hadronic interaction models are the main source of uncertainty of such simulations. We will study how accelerator data can constrain the different hadronic models available for extensive air shower simulations. 1 Cosmic rays and hadronic interactions Due to the steeply falling energy spectrum of cosmic rays, direct detection by satelliteor balloon-borne instruments is only possible up to about ∼ 10 eV. Fortunately, at such high energy, the cascades of secondary particles produced by cosmic rays reach the ground and can be detected in coincidence experiments. The cascades are called extensive air showers (EAS) and are routinely used to make indirect measurements of high energy cosmic rays. As a consequence of the indirect character of the measurement, detailed simulations of EAS are needed to extract information on the primary particle from shower observables. Whereas electromagnetic interactions are well understood within perturbative QED, hadronic multiparticle production cannot be calculated within QCD from first principles. Differences in modeling hadronic interactions, which cannot be resolved by current accelerator data, are the main source of uncertainty of EAS predictions [1, 2]. In this article, we will discuss the relation between hadronic multiparticle production and EAS observables and the constrains given by accelerator data.