Milagro Limits on the Rate-Density of Primordial Black Holes

TL;DR

This paper uses data from the Milagro observatory to set upper limits on the rate of primordial black hole evaporation events, contributing to understanding their possible role as dark matter.

Contribution

It provides the first constraints on primordial black hole evaporation rates using Milagro gamma-ray data, focusing on high-energy gamma-ray bursts.

Findings

No PBH burst detections in Milagro data

Established upper limits on PBH evaporation rate

Constraints consistent with standard model predictions

Abstract

Primordial Black Holes (PBHs) created early in the universe are dark matter candidates. One method of detecting these PBHs is through their Hawking radiation. PBHs created with an initial mass of 5.0 x 10^14 g should be evaporating today with bursts of high-energy particles, including gamma radiation in the GeV - TeV energy range. The Milagro high energy observatory, which operated from 2000 to 2008, is sensitive to the high end of the PBH evaporation gamma ray spectrum. Due to its large field-of-view, more than 90% duty cycle and sensitivity up to 100 TeV gamma rays, the Milagro observatory is ideally suited for the direct search of PBH bursts. Based on a search in Milagro data, we report PBH upper limits according to the standard model.