Systematics of ground-state quadrupole moments of odd-Adeformed nuclei determined with muonicMx rays

Publisher Website
Google Scholar
Abstract
The ground-state quadrupole moments of Eu151, Eu153, Tb159, Dy163, Er167, Hf177, Hf179, Ir191, and Ir193 were determined by measuring the quadrupole hyperfine-splitting energies of muonic M x rays. The results are Q=0.903(10)e b for Eu151, Q=2.412(21) e b for Eu153, Q=1.432(8) e b for Tb159, Q=2.648(21) e b for Dy163, Q=3,565(29) e b for Er167, Q=3.365(29) e b for Hf177, Q=3.793(33) e b for Hf179, Q=0.816(9) e b for Ir191, and Q=0.751(9) e b for Ir193. The present quadrupole moments, compared with values obtained from electronic-atom hyperfine measurements, show that the Sternheimer correction factors used in the rare-earth electronic-atom analysis are unreliable. Systematics of deformation parameters β2 calculated from the present quadrupole moments for odd-A nuclei, and from B(E2) values of Coulomb excitation measurements for even-A nuclei, also indicate that the largest deformation change so far known exists between Eu151 and Eu153. Except at the onset of nuclear deformation, the deformation parameters of the odd-A nuclei are quite consistent with those of the even-A neighbors.