2017/04/30 by Satsuki Oda, Nobuchika Okada, Daisuke Takahashi +1
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Dark matter #Electroweak interaction #Gauge (firearms) #Gauge boson #Gauge theory #Higgs boson #Neutrino #Particle physics #Particle physics theoretical and experimental studies #Physics #Standard Model (mathematical formulation) #hep-ph
paper · pdf · doi:10.1103/physrevd.96.095032
published as Phys. Rev. D 96, 095032 (2017) · 29 pages, 1 table, and 16 figures, version accepted in Phys. Rev. D. arXiv admin note: substantial text overlap with arXiv:1605.01157
openalex created_date 2017/05/26 · arxiv created 2017/11/08 · openalex publication_date 2017/11/29 · arxiv updated 2017/12/06 · openalex updated_date 2026/08/05
We consider the dark matter (DM) scenario in the context of the classically conformal U(1)^\ensuremath' extended standard model (SM), with three right-handed neutrinos (RHNs) and the U(1)^\ensuremath' Higgs field. The model is free from all of the U(1)^\ensuremath' gauge and gravitational anomalies in the presence of the three RHNs. We introduce a Z2 parity in the model, under which an odd parity is assigned to one RHN, while all of the other particles are assigned to be Z2 even, and hence the Z2-odd RHN serves as a DM candidate. In this model, the U(1)^\ensuremath' gauge symmetry is radiatively broken through the Coleman-Weinberg mechanism, by which the electroweak symmetry breaking is triggered. There are three free parameters in our model---the U(1)^\ensuremath' charge of the SM Higgs doublet (xH), the new U(1)^\ensuremath' gauge coupling (gX), and the U(1)^\ensuremath' gauge boson (Z^\ensuremath') mass (m_Z^\ensuremath')---which are severely constrained in order to solve the electroweak vacuum instability problem, and satisfy the LHC Run-2 bounds from the search for the Z^\ensuremath' boson resonance. In addition to these constraints, we investigate the RHN DM physics. Because of the nature of classical conformality, we find that a RHN DM pair mainly annihilates into the SM particles through Z^\ensuremath' boson exchange. This is the so-called Z^\ensuremath'-portal DM scenario. Combining the electroweak vacuum stability condition, the LHC Run-2 bounds, and the cosmological constraint from the observed DM relic density, we find that all constraints work together to narrow the allowed parameter regions and, in particular, exclude m_Z^\ensuremath'\ensuremath\lesssim3.5 TeV. For the obtained allowed regions, we calculate the spin-independent cross section of the RHN DM with nucleons. We find that the resultant cross section is well below the current experimental upper bounds.