Light dark matter candidates in intense laser pulses I: paraphotons and fermionic minicharged particles

Understand

Polarimetric experiments driven by the strong field of a circularly polarized laser wave can become a powerful tool to limit the parameter space of not yet detected hidden-photons and minicharged particles associated with extra U(1) gauge symmetries.

• We show how the absorption and dispersion of probe electromagnetic waves in the vacuum polarized by such a background are modified due to the coupling between the visible U(1)-gauge sector and these hypothetical degrees of freedom.
• The results of this analysis reveal that the regime close to the two-photon reaction threshold can be a sensititive probe of these hidden particles.
• Parameters of modern laser systems are used to estimate the constraints on the corresponding coupling constants in regions where experiments driven by dipole magnets are less constricted.