# ICRC 2021

Jul 12 – 23, 2021
Online
Europe/Berlin timezone

## What if new physics sets in above 50 TeV? Cosmic-ray air-shower simulations with increased cross-section and multiplicity.

Jul 14, 2021, 6:00 PM
1h 30m
03

#### 03

Poster CRI | Cosmic Ray Indirect

### Speaker

Stelios Romanopoulos (University of Crete)

### Description

We have used COSIKA to study, through air-shower simulations, observational signatures of a possible increase in cross-section and multiplicity in collisions with center-of-mass energies exceeding $\sim$ 50 TeV. We have simulated collisions for primaries with energies in the range $10^8 - 10^{12}$ GeV. We have used two different high energy models for the simulations, EPOS LHC and QGSJETII-04, with Fluka for low energy interactions on both. A smooth transition from galactic to extra-galactic cosmic rays was implemented, by fitting a Galactic component with an exponential suppression at $\sim 10^9$ GeV. The remaining flux in Auger data was interpreted as extra-galactic protons. Above $10^{9.3}$ GeV, the proton-air cross-section and the multiplicity of secondary particles were altered, so as to bring the simulated $\langle X_\text{max}\rangle$ in agreement with Auger data. The parameter space of the viable cross-section and multiplicity in the scenario where the composition of Auger cosmic rays at the highest energies remain unchanged and light places constraints on the phenomenology of any new physics affecting the interactions for high energy protons that may be probed by $\sqrt{s}>50$ TeV collisions. The muonic production of the showers was also studied in this context.

### Keywords

EAS Simulations; Particle Physics; Beyond Standard Model; UHECR; Cross Section;

Subcategory Theoretical Results

### Primary authors

Stelios Romanopoulos (University of Crete) Prof. Vasiliki Pavlidou (University of Crete) Prof. Theodore Tomaras (University of Crete)

### Presentation materials

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