Search for TeV Gamma Ray Bursts from Evaporating Primordial Black Holes

Data taken with ACT2 and ACT3 between 1995 and 1997 are used to search for 0.1 s bursts of TeV gamma ray from evaporating primordial black holes (PBHs). There is no evidence for such bursts in the dataset. Using the result, the upper limit of 3x l0⁸ pc^-3yr^-1on the rate-density of evaporating PBHs is set in the vicinity of the solar system at a 99% confidence level.