Studies of Direct Cherenkov Emission with VERITAS

TL;DR

This paper explores the use of the VERITAS telescope system to detect direct Cherenkov light from cosmic rays, aiming to improve composition measurements at TeV energies by distinguishing primary particles from air shower photons.

Contribution

It demonstrates the potential of VERITAS's angular and timing resolution to identify cosmic ray charge and energy through direct Cherenkov emission, a novel application for this telescope system.

Findings

Preliminary detection of direct Cherenkov events with VERITAS.

Potential for event-by-event cosmic ray composition analysis.

Enhanced accuracy in high-energy cosmic ray measurements.

Abstract

Ground-based composition measurements of high-energy cosmic rays can be significantly improved by using the direct Cherenkov method. This technique targets the Cherenkov light produced by the primary particle prior to its production of an extensive air shower. With the appropriate time and angular resolution, the direct Cherenkov photons can be separated from those produced in the extensiveair shower. By utilizing the 0.15 degree angular and 2 nanosecond timing resolution of the very high energy gamma-ray telescope system, VERITAS, the charge and energy of cosmic rays at TeV energies can be identified on an event-by-event basis. Results from a preliminary search for direct Cherenkov events are discussed.