Effect of nonaxial and hexadecapole deformation on the hyperfine splitting of energy levels in 238U muonic atoms

The effect of nonaxial and hexadecapole deformation on spectra of moun atoms is considered, the model of rigid nonaxial rotator being used. Experimental data on μ-238U obtained on the JINR synchrocyclotron are presented. The effect of monopolar, quadrupolar and hexadecapolar parts of potential on muon spectrum is studied using a separated beam of negative 105 MeV/c muons, as the contribution of other harmonics is negligible. Wave functions of 238U nucleus are determined in the framework of the Davydov-Filipov model. The values of charge distribution parameters obtained for 238U are compared with available ones. The comparison shows that the effect of nuclear polarization on quadrupolar splitting of n→n-1 transitions decreases with the growth of n. Quadrupolar splitting of 4F→3D transitions is sufficiently large for experimental studies. Besides, vacuum polarization, radial charge distribution etc. produce an insignificant effect on the above transitions