Jul 3 – 8, 2016
The University of Melbourne
Australia/Melbourne timezone

Minimal Majoronic Dark Radiation and Dark Matter Model and its Phenomenology

Jul 7, 2016, 2:40 PM
Carillo Gantner Theatre

Carillo Gantner Theatre

Carrillo Gantner Theatre, Sidney Myer Asia Centre The University of Melbourne VIC 3010 Australia
Talk Dark Matter and Particle Astrophysics Dark Matter and Particle Astrophysics


We-Fu Chang (National Tsing Hua University)


We study the simplest singlet Majoron model for the dark radiation and dark matter and it 1-loop RGE running.
We found that a smaller effective number of neutrinos $\triangle N_{eff}\sim 0.05$ is preferred.
Moreover, a heavy scalar dark matter, $\rho$, of mass $1.5-4$ TeV is required by the stability of the scalar potential
and an operational type-I see-saw mechanism for neutrino masses. A neutral scalar, $S$, of mass in the $10-100$ GeV range
and its mixing with the standard model Higgs as large as $0.1$ is also predicted.
The dominant decay modes are $S$ into $b\bar{b}$ and/or a pair
of Majorons. A sensitive search will come from rare $Z$ decays
via the chain $Z\rightarrow S+ f\bar{f}$, where $f$ is a Standard Model fermion, followed by $S$ into a pair
of Majorons and/or b-quarks.
The interesting consequences of dark matter bound state due to the sizable $S\rho \rho$-coupling
are discussed as well. In particular, shower-like events with an apparent neutrino energy at $M_\rho$ could contribute to the
observed effective neutrino flux in underground neutrino detectors such as IceCube.

Primary author

We-Fu Chang (National Tsing Hua University)

Presentation materials