The Hybrid Energy Spectrum of TA's Middle Drum Detector and Surface Array

TL;DR

This paper presents the hybrid energy spectrum measurement of the Telescope Array's Middle Drum detector, combining fluorescence and surface array data to improve cosmic ray energy reconstruction and establish links between different detection methods.

Contribution

It introduces a hybrid analysis method that enhances energy measurement accuracy and connects fluorescence and surface array data in the Telescope Array experiment.

Findings

Hybrid spectrum aligns with monocular measurements.

Improved energy reconstruction accuracy.

Establishes link between Middle Drum and surface array data.

Abstract

The Telescope Array experiment studies ultra high energy cosmic rays using a hybrid detector. Fluorescence telescopes measure the longitudinal development of the extensive air shower generated when a primary cosmic ray particle interacts with the atmosphere. Meanwhile, scintillator detectors measure the lateral distribution of secondary shower particles that hit the ground. The Middle Drum (MD) fluorescence telescope station consists of 14 telescopes from the High Resolution Fly's Eye (HiRes) experiment, providing a direct link back to the HiRes measurements. Using the scintillator detector data in conjunction with the telescope data improves the geometrical reconstruction of the showers significantly, and hence, provides a more accurate reconstruction of the energy of the primary particle. The Middle Drum hybrid spectrum is presented and compared to that measured by the Middle Drum station in monocular mode. Further, the hybrid data establishes a link between the Middle Drum data and the surface array. A comparison between the Middle Drum hybrid energy spectrum and scintillator Surface Detector (SD) spectrum is also shown.