A Heitler model of extensive air showers

Review of Model Predictions for Extensive Air Showers

“…Indeed both ⟨X max ⟩ and X max fluctuations depend on the mass composition and since fluctuations are less dependent on the details of hadronic interactions (superposition model [25]) than the mean value, it can be checked that the composition corresponding to a given ⟨X max ⟩ is consistent with the observed fluctuations. In [50] the Pierre Auger Collaboration shows that while it is possible to describe the observed data with EPOS LHC, QGSJETII-04 is in tension with data at a 1 sigma level (⟨X max ⟩ too shallow by ∼15g/cm 2 ).…”

“…A toy-model, as described in [25], gives only a very much over-simplified account of air shower physics. However, the model allows us to qualitatively understand the dependence of many air shower observables on the characteristics of hadronic particle production.…”

“…As shown in [25], the inelastic nuclear cross section is very important for the development of air showers and in particular for the depth of shower maximum. As a consequence, the number of electromagnetic particles at ground level is strongly correlated to this observable (if the shower maximum is closer to ground, the number of particles is higher).…”

“…Another important observable determining air shower development is the elasticity [25] defined as the largest energy fraction carried by a secondary particle (the leading particle). The model pre- Fig .…”

\(\langle X_{\text{max}} \rangle \) Uncertainty from Extrapolation of Cosmic Ray Air Shower Parameters

“…For the prediction of < X max > there are parameters of particle interactions to which the models are particularly sensitive. For example, the total cross section, the multiplicity of produced particles, and the fraction of energy carried away by the leading particles, which is called the elasticity [14] are some of these parameters. An ad hoc model was developed by Ulrich and collaborators [15] who investigated the effect of modifying these interaction parameters.…”