On Signatures of a Possible New Physics Resonance in Atmospheric Air Showers Using a Parameterized Model

We present a parameterized model of atmospheric particle showers initiated by cosmic rays. Few physics shower parameters are tuned in a comparison to the Conex generator. Resulting shower properties are studied, with a comment on the cases where multiple shower maxima develop. Finally, we implement simple models of new physics resonance of masses of 100 GeV and 1 TeV and examine their effects on the shower profile, depth and maximum variation in dependence of the decay channel of the hypothetical resonance. It is shown that a new resonance effects can appear at the energy threshold and can persist for about a decade in $\log_{10} E/\mathrm{eV}$. Various assumed decay modes of the hypothetical resonance have different effects on the direction and shape of the modified average shower depth as function of the energy, with possible implications for current or future measurements. It is shown that, within the presented model, the visibility of the resonance in modified shower depth strongly depends on the resonance width. A significant modification at 10\% width gradually diminishes towards the percent-level width. We propose that looking at the 2D distributions of the two first individual shower moments can also reveal signatures of new physics.