Search for the Hawking radiation of primordial black holes: prospective sensitivity of LHAASO

TL;DR

This paper evaluates LHAASO's capability to detect gamma-ray bursts from evaporating primordial black holes within 0.1 parsecs, predicting it can significantly improve current observational constraints.

Contribution

It introduces a detailed sensitivity assessment of LHAASO for PBH burst detection and proposes optimized data analysis strategies to enhance detection prospects.

Findings

LHAASO can probe PBH bursts within 0.1 pc from the Sun.

LHAASO's sensitivity exceeds HAWC by an order of magnitude.

Potential to measure local burst rate density of ~1200 pc^{-3} yr^{-1}.

Abstract

Primordial black holes (PBHs), more generally, BHs, undergo evaporation and, in principle, will end their lives in bursts of very high-energy gamma rays. The notable aspect of the PBHs with an initial mass of $\sim10^{14}$ g is that they are expected to end their lives today. In this work, we assess the potential sensitivity of the Large High Altitude Air Shower Observatory (LHAASO) in detecting the local burst rate density of PBHs. Our results suggest that LHAASO is capable of probing for PBH bursts within a proximity of $\sim0.1$ pc from the Sun, measuring a local burst rate density of $\sim$ 1200 (or 700)$\,\mathrm{pc}^{-3}\,\mathrm{yr}^{-1}$ with $99\%$ confidence during a 3-year (or 5-year) observational campaign. This level of sensitivity surpasses the most rigorous observational constraint provided by the High Altitude Water Cherenkov Observatory (HAWC) by an order of magnitude. Additionally, we propose data analysis strategies for LHAASO to optimize the search for PBHs and reach its potential detection limits.