G. Ruoso

Measurement of the Casimir force between parallel metallic surfaces.

We report on the measurement of the Casimir force between conducting surfaces in a parallel configuration. The force is exerted between a silicon cantilever coated with chromium and a similar rigid surface and is detected by looking at the shifts induced in the cantilever frequency when the latter is approached. The scaling of the force with the distance between the surfaces was tested in the 0.5-3.0 microm range, and the related force coefficient was determined at the 15% precision level.

New PVLAS results and limits on magnetically induced optical rotation and ellipticity in vacuum

In 2006 the PVLAS collaboration reported the observation of an optical rotation generated in vacuum by a magnetic field. To further check against possible instrumental artifacts, several upgrades to the PVLAS apparatus have been made during the past year. Two data taking runs, at the wavelength of 1064 nm, have been performed in the new configuration with magnetic field strengths of 2.3 and 5 T. The 2.3 T field value was chosen in order to avoid stray fields. The new observations do not show the presence of a rotation signal down to the levels of

A novel experimental approach for the detection of the dynamical Casimir effect

1.2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}\text{ }\text{ }\mathrm{rad}

Limits on low energy photon-photon scattering from an experiment on magnetic vacuum birefringence

at 5 T and

Experimental method to detect the magnetic birefringence of vacuum

1.0\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}\text{ }\text{ }\mathrm{rad}

Measurements of vacuum magnetic birefringence using permanent dipole magnets: the PVLAS experiment

at 2.3 T (at 95% C.L.) with 45 000 passes in the magnetic field zone. In the same conditions no ellipticity signal was detected down to

Measuring the magnetic birefringence of vacuum: the PVLAS experiment

1.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}

Frequency locking of a Nd:YAG laser using the laser itself as the optical phase modulator

at 2.3 T (at 95% C.L.), whereas at 5 T a signal is still present. The physical nature of this ellipticity as due to an effect depending on

Stress-optic modulator: a novel device for high sensitivity linear birefringence measurements

{B}^{2}

Searching for galactic axions through magnetized media: the QUAX proposal

can be excluded by the measurement at 2.3 T. These new results completely exclude the previously published magnetically induced vacuum dichroism results, indicating that they were instrumental artifacts. These new results therefore also exclude the particle interpretation of the previous PVLAS results as due to a spin-zero boson. The background ellipticity at 2.3 T can be used to determine a new limit on the total photon-photon scattering cross section of