Simulation of the cosmic ray tau neutrino telescope (CRTNT) experiment

TL;DR

The paper presents a Monte Carlo simulation for the CRTNT experiment designed to detect ultra-high-energy cosmic tau neutrinos via air showers initiated by tau leptons escaping from mountains.

Contribution

It introduces a detailed simulation framework for the CRTNT experiment, assessing its potential to detect cosmic tau neutrinos and estimate background contamination.

Findings

Expected event rates range from 4.7 to 28.6 per year depending on the neutrino flux model.

Null detection could set a 90% confidence level upper limit on neutrino flux.

Simulation results inform the experiment's sensitivity and background rejection capabilities.

Abstract

A tau lepton can be produced in a charged current interaction by cosmic ray tau neutrino with material inside a mountain. If it escapes from the mountain, it will decay and initiate a shower in the air, which can be detected by an air shower fluorescence/Cherenkov light detector. Designed according to such a principle, the Cosmic Ray Tau Neutrino Telescope (CRTNT) experiment, located at the foothill of Mt. Balikun in Xinjiang, China, will search for very high-energy cosmic tau neutrinos from energetic astrophysical sources by detecting those showers. This paper describes a Monte Carlo simulation for a detection of tau neutrino events by the CRTNT experiment. Ultra-high-energy cosmic ray events are also simulated to estimate the potential contamination. With the CRTNT experiment composed of four detector stations, each covering 64 by 14 degrees field of view, the expected event rates are 28.6, 21.9 and 4.7 per year assuming AGN neutrino flux according to Semikoz et. al. 2004, MPR AGN jet model and SDSS AGN core model, respectively. Null detection of such tau event by the CRTNT experiment in one year could set 90% C.L. upper limit at 19.9 (eV^-1 cm^-2 s^-1 sr^-1) for E^-2 neutrino spectrum.