# Self-triggered radio detection and identification of cosmic air showers with the OVRO-LWA

## TL;DR

This paper demonstrates a novel RF-only self-trigger system for cosmic ray detection using the OVRO-LWA, achieving efficient identification of high-energy cosmic events through advanced RFI mitigation techniques.

## Contribution

It introduces a new RF-only self-trigger method for cosmic ray detection, enhancing detection efficiency and range over traditional particle-based triggers.

## Key findings

- Successful detection of 10 cosmic ray events within 40 hours
- Achieved 45% analysis efficiency for high SNR events
- Proposed design for a future optimized cosmic-ray detector

## Abstract

A successful ground array Radio Frequency (RF)-only self-trigger on 10 high-energy cosmic ray events is demonstrated with 256 dual-polarization antennas of the Owens Valley Radio Observatory Long Wavelength Array (OVRO-LWA). This RF-only capability is predicated on novel techniques for Radio Frequency Interference (RFI) identification and mitigation with an analysis efficiency of 45\% for shower-driven events with a Signal-to-noise ratio $\gtrsim$ 5 against the galactic background noise power of individual antennas. This technique enables more efficient detection of cosmic rays over a wider range of zenith angles than possible via triggers from in-situ particle detectors and can be easily adapted by neutrino experiments relying on RF-only detection. This paper discusses the system design, RFI characterization and mitigation techniques, and initial results from 10 cosmic ray events identified within a 40-hour observing window. A design for a future optimized commensal cosmic-ray detector for the OVRO-LWA is presented, as well as recommendations for developing a similar capability for other experiments -- these designs either reduce data-rate or increase sensitivity by an order of magnitude for many configurations of radio instruments.