Testing the low energy hadronic models used in Aires, with CAPRICE98 results.

P.M. HANSEN, S.J. SCIUTTO, P. CARLSON, M. BOEZIO AND E. MOCCHIUTTI

Merida, Mexico

Conferencia; 30th International Cosmic Ray Conference, Merida, Mexico 2007.; 2007

Air shower simulation programs are used toreconstruct the energy in the UHECR surface detectors.This reconstruction is based on thelateral distribution function obtained in the experiment.It is also known that this function at core distancegreater than 1 km strongly depends on thelow energy hadronic models used in the simulation.There are discrepancies in the particle productiondue to the different models that are used.This discrepancy is not only at high ($> 100 GeV$)  but also at low energy.Almost all collider experiments show difficultiesin the measurement of the diffractivecross section since theydo not register particles emitted into the forward direction.A new version of the air shower simulation programs AIRES,with an improved treatment of the diffractive cross sectionin the low energy hadronic modelwas developed.To cross-check this model, we compare the results of theballoon born experiment CAPRICE98,  onatmospheric fluxes of particles with this new version of AIRES.