We would like to search for nuclear-magnetic cross correlations in inelastic neutron scattering spectra in CeAl2 in which strong coupling between a crystal-field excitation and phonons results in a formation of unique spin-phonon bound state. To this aim, we will measure the non-spin-flip scattering intensity for polarization along z. We will focus on excitation energy between 10 and 20 meV in the medium Q region where both phonon and crystal-field excitations are clearly observed and overlaps each other. A small vertical field will be applied to have single domain state. This study can be serve as a first example to detect nuclear-magnetic interference term.