Revisiting Q-ball Interactions with Matters

Q-ball dark matter is one of the candidates for the macroscopic dark matter: Q-ball is a non-topological solitonic configuration, whose stability can be ensured by global charge and energy conservation. One of the crucial factors for discovering signatures from the Q-ball dark matter, is the interactions of the Q-ball dark matter with ordinary matter. In particular, the scattering of ordinary matter off the Q-ball dark matter is important for the direct detection searches, such as paleo-detectors. It was conjectured that quarks incident on the Q-ball were reflected as anti-quarks with a probability of order unity, but it costs the energy of the squark in the Q-ball, which cannot be paid in the scattering of ordinary matter off the Q-ball dark matter. In addition, once a proton is reflected as an anti-proton, the Q-ball obtains the electromagnetic charge. In this study, we revisit the scattering process of quarks with the Q-ball with taking into account the energy cost of the scattering and the electromagnetic charge-up of the Q-ball.

💡 Research Summary

This paper revisits the scattering of quarks (and consequently nucleons) off Q‑ball dark matter, addressing two crucial aspects that were omitted in earlier treatments. Q‑balls are non‑topological solitons that can arise in supersymmetric extensions of the Standard Model; they are stabilized by a conserved global charge and by the balance between gradient and potential energy of a scalar field that acquires a large vacuum expectation value along a flat direction. Earlier works (e.g., Ref.