Experimental Limits on the Photon Mass and Cosmic Magnetic Vector Potential
Abstract
A novel experimental approach based on a toroid Cavendish balance is used to evaluate the product of photon mass squared and the ambient cosmic magnetic vector potential A. The method is based on the energy density of the vector potential in the presence of photon mass, not on measurement of the magnetic field. The experiment discloses Aμ^{2}_{γ}<2×10^{9} T m/m^{2}, with μ^{1}_{γ} as the characteristic length associated with photon mass. Consequently, if the ambient magnetic vector potential is A~10^{12} T m due to cluster level fields, μ^{1}_{γ}>2×10^{10} m. If we conservatively use galactic fields prior to a reversal, then μ^{1}_{γ}>1×10^{9} m, a figure still superior to that derived from the Jovian magnetic field.
 Publication:

Physical Review Letters
 Pub Date:
 March 1998
 DOI:
 10.1103/PhysRevLett.80.1826
 Bibcode:
 1998PhRvL..80.1826L