Limits to gauge coupling in the dark sector set by the non-observation of instanton-induced decay of Super-Heavy Dark Matter in the Pierre Auger Observatory data

THE PIERRE AUGER COLLABORATION.; S. J. SCIUTTO

PHYSICAL REVIEW LETTERS

AMER PHYSICAL SOC

Lugar: New York; Año: 2023 vol. 130

0031-9007

Instantons, which are nonperturbative solutions to Yang-Mills equations, provide a signal for theoccurrence of quantum tunneling between distinct classes of vacua. They can give rise to decays of particles otherwise forbidden. Using data collected at the Pierre Auger Observatory, we search for signatures of suchinstanton-induced processes that would be suggestive of super-heavy particles decaying in the Galactichalo. These particles could have been produced during the post-inflationary epoch and match the relicabundance of dark matter inferred today. The nonobservation of the signatures searched for allows us toderive a bound on the reduced coupling constant of gauge interactions in the dark sector: αX ≲ 0.09, for109 ≲ MX=GeV < 1019. Conversely, we obtain that, for instance, a reduced coupling constant αX ¼ 0.09excludes masses MX ≳ 3 × 1013 GeV. In the context of dark matter production from gravitationalinteractions alone, we illustrate how these bounds are complementary to those obtained on the Hubblerate at the end of inflation from the nonobservation of tensor modes in the cosmological microwavebackground.