EXPERIMENTAL-EVIDENCE FOR NONCLASSICAL 4TH-ORDER INTERFERENCES IN THEQUASI-ELASTIC LIGHT-SCATTERING OF WATER

Experimental results of quasielastic light scattering on a water-HCl m ixture at T = 297 K are reported, which demonstrate the existence of a different kind of nonclassical two-photon (fourth-order) correlation, in the absence of second-order interferences. The normalized two-phot on correlation function lambda((2))(1,2) shows an oscillation with an amplitude of about 25%, depending on the relative position of the two detectors and the scattering source. The equivalent measurement on CS2 shows no such effect. The possible physical significance of the obser vations is briefly mentioned.