Measurement of the Proton-Air Cross Section with Telescope Array's Middle Drum Detector and Surface Array in Hybrid Mode

Understand

In this work we are reporting on the measurement of the proton-air inelastic cross section $\sigma^{\rm inel}_{\rm p-air}$ using the Telescope Array (TA) detector.

• Based on the measurement of the $\sigma^{\rm inel}_{\rm p-air}$ the proton-proton cross section $\sigma_{\rm p-p}$ value is also determined at $\sqrt{s} = 95_{-8}^{+5}$ TeV.
• Detecting cosmic ray events at ultra high energies with Telescope Array enables us to study this fundamental parameter that we are otherwise unable to access with particle accelerators.
• The data used in this report is the hybrid events observed by the Middle Drum fluorescence detector together with the surface array detector collected over five years.