The intensity dependent mass shift: existence, universality and detection

Understand

The electron mass shift in a laser field has long remained an elusive concept.

• We show that the mass shift can exist in pulses but that it is neither unique nor universal: it can be reduced by pulse shaping.
• We show also that the detection of mass shift effects in laser-particle scattering experiments is feasible with current technology, even allowing for the transverse structure of realistic beams.