Conformal B − L and pseudo-Goldstone dark matter

• Published in: Physical review. D 2023-05, Vol.107 (9), Article 095023
• Main Authors: Mohapatra, Rabindra N., Okada, Nobuchika
• Format: Article
• Language: English
• Subjects: Astronomy & Astrophysics; ASTRONOMY AND ASTROPHYSICS; Conformal field theory; Extensions of gauge sector; Physics
• ISSN: 2470-0010; 2470-0029
• DOI: 10.1103/PhysRevD.107.095023

We show that a conformal extension of the standard model with local B – L symmetry and two complex scalars breaking B – L can provide a unified description of neutrino mass, origin of matter, and dark matter. There are two hierarchical B – L breaking vacuum expectation value (VEV) scales in the model, the higher denoted by vB and the lower by vA. The higher breaking scale is dynamically implemented via the Coleman-Weinberg mechanism and plays a key role in the model since it induces electroweak symmetry breaking as well as the lower B – L breaking scale. It is also responsible for neutrino masses via the seesaw mechanism and origin of matter. The imaginary part of the complex scalar with lower B – L breaking VEV plays the role of a pseudo-Goldstone dark matter (DM). The DM particle is unstable with its lifetime naturally longer than 1028 seconds. We show that its relic density arises from the freeze-in mechanism for a wide parameter domain. Due to the pseudo-Goldstone boson nature of the DM particle, the direct detection cross section is highly suppressed. The model also predicts the dark matter to be heavier than 100 TeV and it decays to two high energy neutrinos which can be observable at the IceCube, providing a test of this model.