The ANITA Anomalous Events and Axion Quark Nuggets

Abstract

The Antarctic Impulse Transient Antenna (\textsc{ANITA}) collaboration [1-3] has reported two anomalous events with noninverted polarity. These events are hard to explain in terms of conventional cosmic rays (CRs). We explore a new possible explanation for these anomalous events by suggesting that these events can be related to the dark matter (DM) annihilations within the so-called axion quark nugget (AQN) DM model. This model was initially invented for a completely different purpose to explain the observed similarity between the dark and the visible components in the Universe, i.e. $\Omega_{\rm DM}\sim \Omega_{\rm visible}$ without any fitting parameters. We investigate the signal properties of the upward-going AQN events, including the event rate, the pulse duration, and the electric field strength, and find them consistent with the observations. We list several features of the upward-going AQN events distinct from conventional CR air showers. The observations (or nonobservation) of these features may substantiate (or refute) our proposal.