Accidental dark matter: Case in the scale invariant local B -L model
Abstract
We explore the idea of accidental dark matter (aDM) stability in the scale invariant local U (1 )B -L model, which is a theory for neutrino and at the same time radiatively breaks scale invariance via quantum mechanical dynamics in the U (1 )B-L sector. A real singlet scalar can be accidental DM with an accidental Z2, by virtue of both extended symmetries. A U (1 )B-L charged complex scalar can also be a viable accidental DM due to an accidental (or remanent) Z3. They can reproduce correct relic density via the annihilations through the conventional Higgs portal or dark Higgs portal. The dark Higgs portal scenario is in tension with the LHC bound on ZB -L, and only heavy DM of a few TeVs can have correct relic density. In particular, DM may trigger classical scale invariance spontaneous breaking. The situation is relaxed significantly in the Z3 case due to the effective semiannihilation mode, and then light DM can be accommodated easily. In addition, the Z3 model can accommodate the GeV scale γ -ray excess from the Galactic center via semiannihilation into pseudo-Goldstone boson. The best fit is achieved at a DM about 52 GeV, with an annihilation cross section consistent with the thermal relic density. The invisible Higgs branching ratio is negligible because the Higgs portal quartic coupling is very small λh ϕ≲10-3.
- Publication:
-
Physical Review D
- Pub Date:
- June 2015
- DOI:
- 10.1103/PhysRevD.91.115017
- arXiv:
- arXiv:1502.00508
- Bibcode:
- 2015PhRvD..91k5017G
- Keywords:
-
- 12.60.Jv;
- 14.70.Pw;
- 95.35.+d;
- Supersymmetric models;
- Other gauge bosons;
- Dark matter;
- High Energy Physics - Phenomenology
- E-Print:
- Journal version, including more remarks in particular about the the condition for the accidental Z2 surviving