148 research outputs found
From gamma ray line signals of dark matter to the LHC
We explore the relationship between astrophysical gamma-ray signals and LHC
signatures for a class of phenomenologically successful secluded dark matter
models, motivated by recent evidence for a ~130 GeV gamma-ray line. We consider
in detail scenarios in which interactions between the dark sector and the
standard model are mediated by a vev-less scalar field \phi, transforming as an
N-plet (N > 3) under SU(2)_L. Since some of the component fields of \phi carry
large electric charges, loop induced dark matter annihilation to \gamma \gamma
and \gamma Z can be enhanced without the need for non-perturbatively large
couplings, and without overproduction of continuum gamma-rays from other final
states. We discuss prospects for other experimental tests, including dark
matter-nucleon scattering and production of \phi at the LHC, where future
searches for anomalous charged tracks may be sensitive. The first LHC hints
could come from the Higgs sector, where loop corrections involving \phi lead to
significantly modified h to \gamma \gamma and h to \gamma Z branching ratios.Comment: 27 pages, 10 figures. v2: added references, fixed import-order issue
with cleveref and hyperref. v3: updated to journal version. v4: erratum
correction to figs. 7-8 for monojet/monophoton cross-section
Unified Scenario for Composite Right-Handed Neutrinos and Dark Matter
We entertain the possibility that neutrino masses and dark matter (DM)
originate from a common composite dark sector. A minimal effective theory can
be constructed based on a dark interaction with three flavors of
massless dark quarks; electroweak symmetry breaking gives masses to the dark
quarks. By assigning a charge to one flavor, a stable "dark kaon"
can provide a good thermal relic DM candidate. We find that "dark neutrons" may
be identified as right handed Dirac neutrinos. Some level of
"neutron-anti-neutron" oscillation in the dark sector can then result in
non-zero Majorana masses for light Standard Model neutrinos. A simple
ultraviolet completion is presented, involving additional heavy
-charged particles with electroweak and lepton Yukawa couplings. At
our benchmark point, there are "dark pions" that are much lighter than the
Higgs and we expect spectacular collider signals arising from the UV framework.
This includes the decay of the Higgs boson to ,
where () can be any lepton, with displaced vertices. We discuss
the observational signatures of this UV framework in dark matter searches and
primordial gravitational wave experiments; the latter signature is potentially
correlated with the decay.Comment: 8 pages, 4 figures, 1 table. Version published on PR
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