Eur. Phys. J. C (2020) 80: 259
https://doi.org/10.1140/epjc/s10052-020-7816-y

Letter

Looking at the axionic dark sector with ANITA

¹ Departament de Fisíca Quàntica i Astrofísica and Institut de Ciències del Cosmos, Universitat de Barcelona, Diagonal 647, 08028, Barcelona, Spain
² Instituto de Física Corpuscular, Universidad de Valencia and CSIC, Edificio Institutos Investigación, Catedrático José Beltrán 2, 46980, Valencia, Spain
³ Theoretical Physics Department, Fermi National Accelerator Laboratory, P.O. Box 500, Batavia, IL, 60510, USA
⁴ Department of Physics and Astronomy, Northwestern University, Evanston, IL, 60208, USA
⁵ Colegio de Física Fundamental e Interdisciplinaria de las Américas (COFI), 254 Norzagaray street, San Juan, Puerto Rico, 00901, USA

^* e-mail: jsalvado@icc.ub.edu

Received: 11 December 2019
Accepted: 6 March 2020
Published online: 20 March 2020

Abstract

The ANITA experiment has recently observed two anomalous events emerging from well below the horizon. Even though they are consistent with tau cascades, a high-energy Standard Model or Beyond the Standard Model explanation is challenging and in tension with other experiments. We study under which conditions the reflection of generic radio pulses can reproduce these signals. Furthermore, we propose that these pulses can be resonantly produced in the ionosphere via axion–photon conversion. This naturally explains the direction and polarization of the events and avoids other experimental bounds.