Abstract
Several single-modal Debye correlation functions are closely examined to elucidate the behavior
of their corresponding SESANS (Spin Echo Small Angle Neutron Scattering) correlation functions.
We ¯nd that the upper bound of a Debye correlation function and of its SESANS correlation func-
tion is identical. For discrete Debye correlation functions, the peak of SESANS correlation function
emerges at their ¯rst discrete point, whereas for continuous Debye correlation functions with greater
width, the peak position shifts to a greater value. In both cases, the intensity and shape of the
peak of the SESANS correlation function are determined by the width of the normalized Debye
correlation functions. In the application, we mimic the intramolecular and intermolecular Debye
correlation functions of liquids composed of interacting particles by using the simple models to
elucidate their competition in the SESANS correlation function. Our calculations show that the
position of the ¯rst minimum of SESANS correlation function shifts to a smaller value as inter-
molecular attraction or correlation is enhanced. The minimum value can be positive or negative,
and the positive values are observed for the cases equivalent to stronger intermolecular attraction,
consistent with literature results based on more sophisticated liquid state theory and simulations.
