  We present a novel electric-field-resolved approach for probing ultrafast
dynamics of localized surface plasmons in metallic nanoparticles. The electric
field of the broadband carrier-envelope-phase stable few-cycle light pulse
employed in the experiment provides access to time-domain signatures of
plasmonic dynamics that are imprinted on the pulse waveform. The simultaneous
access to absolute spectral amplitudes and phases of the interacting light
allows us obtaining a complex spectral response associated with localized
surface plasmons. We benchmark our findings against the absorbance spectrum
obtained with a spectrometer as well as the extinction cross-section modeled by
a classical Mie scattering theory.
