Measurement of the charge moments of the even-even gadolinium nuclei by muonic atoms

Muonic x-ray measurements on the even-A gadolinium isotopes 154, 156, 158, and 160Gd have been made. The data have been analysed in a nearly model-independent manner to extract electric monopole and quadrupole moments for the low-lying states. The equivalent nuclear charge radii (Barrett radii) have been determined for the ground states with uncertainties of about 1 mfm. Extracted isotope shifts δ is greater than have been found to agree with electronic K/sub alpha/ x-ray measurements, but not with optical measurements. Normalized optical isotope shifts do agree. The isomer shifts of the 2/sub g/+ states were measured directly from the muonic K x-rays. For 158Gd, disagreement with previous muonic x-ray measurements was found. Generalized quadrupole moments of the charge distribution as measured by muonic atoms have been determined and equivalent quadrupole radii for transitional quadrupole charge distributions of the 2/sub g/+ states have been determined in conjuction with recent Coulomb excitation data. Pairing-Plus-Quadrupole (PPQ) Model calculations agree with extracted quadrupole moments using equal static and transitional quadrupole charge radii