Study of the magneto-optical properties of quantum vacuum with high sensitivity polarimetry

by Giuseppe Messineo (Istituto Nazionale di Fisica Nucleare)

Wednesday 5 Apr 2023, 17:00 → 18:30 Europe/Rome

Nonlinear electrodynamic effects in vacuum have been predicted since the
early days of Quantum Electrodynamics with the formulation of the Euler
effective Lagrangian in 1935.
One of these effects is vacuum magnetic birefringence, according to which
vacuum, under the influence of an external magnetic field, becomes
birefringent with a different index of refraction in the direction
perpendicular and parallel to the applied field.
Although experimental efforts have been active for about 40 years, a
direct laboratory observation of vacuum magnetic birefringence is still
lacking. The predicted effect is extremely small ($\Delta n = 4.0\times
10^{-24}$ @ 1~T): the current experimental strategy is to employ
high-sensitivity polarimeters and long optical paths in intense magnetic
fields to detect small polarization changes on linearly polarized probe
laser beams.

I will review the current status of measurements of vacuum magnetic
birefringence and present new approaches to improve the sensitivity of
future experiments. Moreover, I will discuss a recent proposal to use
polarimetry to search for low-mass dark matter particles, such as axions
and axion-like particles (ALPs).

Meeting ID: 694 9192 9100

Passcode: 095417

https://cern.zoom.us/j/69491929100?pwd=eEVGRVFzZjREYjZSMm9pNFJYZVZZUT09

Messineo-Fellini_Mar23_slides.pdf