The shape of gold

Having a detailed theoretical knowledge of the low-energy structure of the heavy odd-mass nucleus Au-197 is of prime interest as the structure of this isotope repre-sents an important input to theoretical simulations of col-lider experiments involving gold ions performed at relativis-tic energies. In the present article, therefore, we report on new results on the structure of Au-197 obtained from state-of-the-art multi-reference energy density functional (MR-EDF) calculations. Our MR-EDF calculations were real-ized using the Skyrme-type pseudo-potential SLyMR1, and include beyond mean-field correlations through the mixing, in the spirit of the Generator Coordinate Method (GCM), of particle-number and angular-momentum projected triax-ially deformed Bogoliubov quasi-particle states. Compari-son with experimental data shows that the model gives a reasonable description of Au-197 with in particular a good agreement for most of the spectroscopic properties of the 3/2(1)(+) ground state. From the collective wave function of the correlated state, we compute an average deformation (beta) over bar (3/2(1)(+)) = 0.13 and (gamma) over bar (3/2(1)(+)) = 40 degrees for the ground state. We use this result to construct an intrinsic shape of 197Au representing a microscopically-motivated input for precision simulations of the associated collider processes. We discuss, in particular, how the triaxiality of this nucleus is expected to impact Au-197+Au-197 collision experiments at ultrarelativis-tic energy.