Search

In this work we give a comprehensive analysis on the phenomenology of a specific $\mathbb{Z}_3$ dark matter (DM) model in which neutrino mass is induced at two loops by interactions with a DM particle that can be a complex scalar or a Dirac fermion. Both the DM properties in relic density and direct detection and the LHC signatures are examined in great detail, and indirect detection for gamma-ray excess from the Galactic Center is also discussed briefly. On the DM side, both semi-annihilation and co-annihilation processes play a crucial role in alleviating the tension of parameter space between relic density and direct detection. On the collider side, new decay channels resulting from $\mathbb{Z}_3$ particles lead to distinct signals at LHC. Currently the trilepton signal is expected to give the most stringent bound for both scalar and fermion DM candidates, and the signatures of fermion DM are very similar to those of electroweakinos in simplified supersymmetric models., Comment: 40 pages, 24 figures

If the c-quark has an anomalous color-electric dipole moment (CEDM), it may serve as a new source of CP violation. The strength of such a CP violation depends on the size of the CEDM, d'_c. We propose two effective ways of testing it from the large sample of psi'->J/psi+pi(+)+pi(-) at the Beijing Spectrometer, and the obtained result, |d'_c|<3X10^{-14} e cm (95% C.L.), gives the first experimentally determined upper bound on the CEDM of the c quark., Comment: 26 pages RevTex4 file with 4 eps files for the figures. Some discussions and new references added