Mario Pimenta (LIP Laboratorio de Instrumentaco e Fisica Experimental de Particulas)
In this work we study the energy evolution of the number of muons in air showers. Motivated by future plans for UHECR experiments, the analysis developed here focus on how the evolution of the moments of the shower observables distributions (Xmax and the number of muons at ground) can be used to assess the validity of a mass composition scenario, surpassing the current uncertainties on the shower description. The cosmic ray composition is an essential ingredient for an astrophysical interpretation of the data. However, the inference of composition from air shower measurements is limited by the theoretical uncertainties on the high energy hadronic interactions. Statistical analyses using the energy evolution of different observables, like the moments of the Xmax and of the moments of the number of muons distributions, can provide an efficient method to surpass these limitations imposed by the uncertainties in hadronic interaction models and provide more reliable information about the cosmic ray abundance. A new technique is presented here to generate a large set of simulated shower observables minimizing computer processing time. Fast algorithms to simulate the longitudinal development of the shower (i.e. CONEX) are long available. However, the number of muons is measured along the lateral development of the shower, which implies that tridimensional simulations are needed (i.e. CORSIKA). This paper presents a parameterization of the main shower characteristics that can be used to simulate the muon lateral distribution on ground using fast simulation algorithms. The parametrization was used in CONEX to produce a large library of showers. Xmax and the lateral distribution of muons were simulated. These showers were used to explore and discriminate among hypothetic astrophysical scenarios of mass composition.
|Registration number following "ICRC2015-I/"||593|
|Collaboration||-- not specified --|
Mr Raul Ribeiro Prado (Instituto de Física de São Carlos -USP)