We report the updated observational search for tau neutrinos (ν τ) using one of the Ashra light collectors, which faces to Mauna Kea, on Mauna Loa at 3300 m above sea level on Hawaii Island. The earth-skimming ν τ technique of imaging Cherenkov τ showers was applied as a detection method. We checked the detection sensitivity and the reconstruction procedure for the Cherenkov τ shower well with sufficient statistics, i.e. 824 events of ordinary cosmic-ray airshower Cherenkov images for a total of 1884 hours using the same instruments, but triggered with the attached trigger pixel layout to view the sky field above the mountain. The analysis of about 1863 hours of data taken towards the mountain of Mauna Kea and the Earth crust around it leads to a 90% C.L. point source limit for ν τ in the energy range from 3 PeV to 10 EeV of about E 2 ν τ • φ (E ν τ) < 3.2 × 10 −7 GeV cm −2 s −1 assuming power-law ν spectrum with the index of-2. The analysis status of about 5783 hours of optical transients data is also presented.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.