831 research outputs found
Air showers, hadronic models, and muon production
We report on a study about some characteristics of muon production during the
development of extended air showers initiated by ultra-high-energy cosmic rays.
Using simulations with the recent new version of the AIRES air shower
simulation system, we analyze and discuss on the observed discrepancies between
experimental measurements and simulated data.Comment: Presented at UHECR 2018 (Paris, Oct 2018
Influence of diffractive interactions on cosmic ray air showers
A comparative study of commonly used hadronic collision simulation packages
is presented. The characteristics of the products of hadron-nucleus collisions
are analyzed from a general perspective, but focusing on their correlation with
diffractive processes. One of the purposes of our work is to give quantitative
estimations of the impact that different characteristics of the hadronic models
have on air shower observables. Several sets of shower simulations using
different settings for the parameters controlling the diffractive processes are
used to analyze the correlations between diffractivity and shower observables.
We find that the relative probability of diffractive processes during the
shower development have a non negligible influence over the longitudinal
profile as well as the distribution of muons at ground level. The implications
on experimental data analysis are discussed
Production and propagation of heavy hadrons in air-shower simulators
Very energetic charm and bottom hadrons may be produced in the upper
atmosphere when a primary cosmic ray or the leading hadron in an extensive air
shower collide with a nucleon. At GeV their decay length
becomes of the order of 10 km, implying that they tend to interact in the air
instead of decaying. Since the inelasticity in these collisions is much smaller
than the one in proton and pion collisions, there could be rare events where a
heavy-hadron component transports a significant amount of energy deep into the
atmosphere. We have developed a module for the detailed simulation of these
processes and have included it in a new version of the air shower simulator
AIRES. We study the frequency, the energy distribution and the depth of charm
and bottom production, as well as the depth and the energy distribution of
these quarks when they decay. As an illustration, we consider the production
and decay of tau leptons (from decays) and the lepton flux at PeV
energies from a 30 EeV proton primary. The proper inclusion of charm and bottom
hadrons in AIRES opens the possibility to search for air-shower observables
that are sensitive to heavy quark effects.Comment: Accepted for publication in Astroparticle Physic
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