Multi-Component Dark Matter: the vector and fermion case

Oct 4, 2017
25 pages
Published in:
  • Eur.Phys.J.C 78 (2018) 11, 905
  • Published: Nov 9, 2018
e-Print:
Report number:
  • MITP/17-065,
  • MITP-17-065

Citations per year

20172019202120232025051015
Abstract: (Springer)
Multi-component dark matter scenarios constitute natural extensions of standard single-component setups and offer attractive new dynamics that could be adopted to solve various puzzles of dark matter. In this work we present and illustrate properties of a minimal UV-complete vector-fermion dark matter model where two or three dark sector particles are stable. The model we consider is an extension of the Standard Model (SM) by spontaneously broken extra U(1)XU(1)_X gauge symmetry and a Dirac fermion. All terms in the Lagrangian which are consistent with the assumed symmetry are present, so the model is renormalizable and consistent. To generate mass for the dark-vector XμX_\mu the Higgs mechanism with a complex singlet S is employed in the dark sector. Dark matter candidates are the massive vector boson XμX_\mu and two Majorana fermions ψ±\psi _\pm . All the dark sector fields are singlets under the SM gauge group. The set of three coupled Boltzmann equations has been solved numerically and discussed. We have performed scans over the parameter space of the model implementing the total relic abundance and direct detection constraints. The dynamics of the vector-fermion dark matter model is very rich and various interesting phenomena appear, in particular, when the standard annihilations of a given dark matter are suppressed then the semi-annihilations, conversions and decays within the dark sector are crucial for the evolution of relic abundance and its present value. Possibility of enhanced self-interaction has been also discussed.
Note:
  • v2: 25 pages + appendices, 12 captioned figures, a section on multi-component self-interacting dark matter is added, matches the journal accepted version
  • fermion: Majorana
  • vector boson: massive
  • dark matter
  • Boltzmann equation
  • Higgs mechanism
  • annihilation
  • suppression
  • numerical calculations
  • Z(2) x Z(2)