Do Mie plasmons have a longer lifetime on resonance than off resonance?

The dynamics of laser-excited electrons in elliptically shaped silver nano- particles is studied using time-resolved two-photon photo-emission. By chan ging the polarization of the laser pulse at a fixed frequency, a different dynamics is observed near and far from resonance. To analyze these data , t he effect of radiation damping on Mie plasmons of Ag nanoparticles is studi ed as a function of laser frequency and polarization. It is shown that the off-resonance lifetime can be shorter or longer than the lifetime at resona nce, depending on the incidence conditions of the laser light and on the de polarization factors characterizing the optical response of the nano-partic les.