Significant Bremsstrahlung from scalar dark matter

par Michel Tytgat (Université Libre de Bruxelles)

jeudi 28 nov. 2013, 11:00 → 12:00 Europe/Paris

Salle des Sommets (Annecy-le-Vieux)

There has been recently much interest on dark matter candidates that may give rise to observable gamma-ray spectral features, like a gamma-ray line. In this talk I discuss a very simple model, based on a real scalar dark matter candidate that interacts with Standard Model fermions through heavy vector-like fermions (a scenario that has been dubbed "Vector-Like Portal"). I show that the annihilation of dark matter into light fermions is d-wave suppressed while radiative corrections, in particular internal Bremsstrahlhung, are enhanced. For the sake of comparison, I confront this scenario to the familiar case of a Majorana singlet annihilating into light lepton-antilepton pairs, and show that the virtual internal bremsstrahlung signal may be enhanced by a factor of (up to) two orders of magnitude, thus potentially leading to significant gamma-ray features. I discuss the phenomenological implications of this scenario and its possible extensions.