# Rare Events searches with Cherenkov Telescopes

## TL;DR

This paper discusses the potential of Cherenkov Telescope Arrays to detect rare or exotic events hidden within the abundant cosmic ray background, exploring their data and reconstruction challenges.

## Contribution

It introduces the idea of analyzing background events in Cherenkov telescopes for potential rare or exotic signals, highlighting new opportunities in data analysis.

## Key findings

- Background events may contain valuable signals.
- Current veto strategies may overlook exotic signatures.
- Challenges in reconstructing rare events are identified.

## Abstract

Ground-based Imaging Cherenkov Telescope Arrays observe the Cherenkov radiation emitted in extended atmospheric showers generated by cosmic gamma rays in the TeV regime. The rate of these events is normally overwhelmed by 2-3 orders of magnitude more abundant cosmic rays induced showers. A large fraction of these 'background' events is vetoed at the online trigger level, but a substantial fraction still goes through data acquisition system and is saved for the offline reconstruction. What kind of information those events carry, normally rejected in the analysis? Is there the possibility that an exotic signature is hidden in those data? In the contribution, some science cases, and the problems related to the event reconstruction for the current and future generation of these telescopes will be discussed.