ALPS seminar

# Model independent limits on Axion like particles from ellipticity measurements

## by Prof. Guido Zavattini (University of Ferrara)

Wednesday, January 14, 2015 from to (Europe/Berlin)
at DESY Hamburg ( 4a )
 Description A new highly sensitive ellipsometer is now running at the Department of Physics and INFN of Ferrara, Italy. The apparatus has been designed to detect very small magnetically induced birefringences with the ultimate goal of measuring vacuum magnetic birefringence. This challenging goal is not yet achievable due to excess noise which is under study. Nonetheless a new limit on vacuum magnetic birefringence has been recently set. Taking advantage of the cavity intrinsic birefringence, our ellipticity limit can also be used to set a dichroism limit. From these two values we set model independent limits on the coupling constant of axion like particles to two photons. Material: Organised by babette.doebrich@desy.de