  The present work focuses on the characterisation of the amount of orbital
angular momentum (OAM) encoded in the twisted attosecond pulses via energy- and
angle-resolved attosecond streaking in pump-probe setup. It is found that the
photoelectron spectra generated by the linearly polarised twisted pulse with
different OAM values exhibit angular modulations, whereas circularly polarised
twisted pulse yields angular isotropic spectra. It is demonstrated that the
energy- and angle-resolved streaking spectra are sensitive to the OAM values of
the twisted pulse. Moreover, the different combinations of the polarisation of
the twisted pump pulse and strong infrared probe pulse influence the streaking
spectra differently. The characterisation of the OAM carrying twisted
attosecond pulses opens up the possibility to explore helical light-matter
interaction on attosecond timescale.
