Conformal B-L and Pseudo-Goldstone Dark Matter

Abstract

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 $v_B$ and the lower by $v_A$. 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 $10^{28}$ 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.

16 pages and seven figures; references updated

References in corpus (14)

• BICEP / Keck XIII: Improved Constraints on Primordial Gravitational Waves using Planck, WMAP, and BICEP/Keck Observations through the 2018 Observing Season
• Conformal Symmetry and the Standard Model
• A solution to the hierarchy problem from an almost decoupled hidden sector within a classically scale invariant theory
• Electroweak Higgs as a pseudo-Goldstone boson of broken scale invariance
• Shadow Higgs from a scale-invariant hidden $U(1{)}_s$ model
• Effective Action, Conformal Anomaly and the Issue of Quadratic Divergences
• The Inverse Seesaw in Conformal Electro-Weak Symmetry Breaking and Phenomenological Consequences
• Corrigendum to "Flavour Covariant Transport Equations: an Application to Resonant Leptogenesis"
• Pseudo Nambu-Goldstone Dark Matter: Examples of Vanishing Direct Detection Cross Section
• Direct and indirect probes of Goldstone dark matter
• Conformal invariance from non-conformal gravity
• Freeze-in Dark Matter from a Minimal B-L Model and Possible Grand Unification
• Heavy neutrinos and neutral gauge boson Z' at the LHC
• Low energy implications of cosmological data in $U(1{)}_X$ Higgs inflation