Condensed Matter Physics, 2013, vol. 16, No. 1, 13003
Experimental observation of triple correlations in fluids
(Mechnikov National University, Department of Theoretical Physics, 2 Dvoryanska St., 65026 Odesa, Ukraine)
We present arguments for the hypothesis that under some conditions, triple correlations of density fluctuations in fluids can be detected experimentally by the method of molecular spectroscopy. These correlations manifest themselves in the form of so-called 1.5-(or sesquialteral) scattering. The latter is of most significance in the pre-asymptotic vicinity of the critical point and can be registered along certain thermodynamic paths. Its presence in the overall scattering pattern is demonstrated by our processing available experimental data for the depolarization factor. Some consequences of these results are discussed.
density fluctuations, critical opalescence, 1.5-scattering, depolarization factor
05.40, 05.70.Fh, 05.70.Jk, 64.70.Fx, 78.35.+c