Temperature dependence of the rotational life times in solid H2

A study was made of the temperature dependence of the nuclear transverse and longitudinal relaxation in solid H2 for ortho concentrations 10-3 < X < 10-2 between 0.4 K and the triple point, 13.9 K. A striking temperature dependence in T2 over the whole temperature range is found. This new effect is ascribed to a coupling between molecular rotation and lattice vibrations, which is brought into evidence by the narrow width of the spectral density of the rotational fluctuations at low X. (author)