APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Peiwen Wu (KIAS)
Title: Top and Top+Charm Flavored Scalar Dark Matter with a Vector-like Fermion Partner
Date (JST): Fri, Feb 24, 2017, 13:30 - 14:30
Place: Seminar Room B
Abstract: The absence of unambiguous signals from dark matter (DM) direct detection (DD) may suggest a weak coupling between DM and first generation quark. In this work we considered a scalar dark matter which couples dominantly to one or two generations of heavy quarks, i.e. top quark and top+charm quarks. The heavy quark masses should not be ignored in the calculations of thermal relic, especially for the scalar DM which receives both chiral and p-wave suppression. The DD scattering processes start at one-loop level and come from the DM scattering with the gluons in the nucleon. Flavor Changing Neutral Current (FCNC) processes $t \to c V$, where $V$ represents photon, Z and gluon, are induced for top quark in the top+charm flavored DM scenario and the branching ratio can reach 10^-6 for V=photon and 10^-5 for V=Z and gluon. We also studied the collider signals for this model.