Identification of 3.55 KeV line in the framework of standard physics

TL;DR

This paper proposes that the 3.55 KeV X-ray line can be explained as a recombination line of a $^-$ tritium mesoatom, suggesting it can occur under standard physics conditions without new physics.

Contribution

It introduces a novel explanation for the 3.55 KeV line as a standard physics recombination process involving a $^-$ mesoatom, challenging previous interpretations requiring new physics.

Findings

The 3.55 KeV line can be produced by $^-$ tritium mesoatom recombination.

Such atoms can form under laboratory conditions without new physics.

The proposed mechanism explains the observed X-ray line without exotic particles.

Abstract

Identification of the X-ray 3.55 KeV line as a recombination line of $\pi^-$ tritium mesoatom is proposed. It has been shown that in principle it is possible to form such an atom under standard laboratory conditions, without bringing in new physics.