Theoretical predictions suggest the presence of tetrahedral symmetry as an
explanation for the vanishing intra-band E2-transitions at the bottom of the
odd-spin negative parity band in 156Gd. The present study reports on
experiment performed to address this phenomenon. It allowed to determine the
intra-band E2 transitions and branching ratios B(E2)/B(E1) of two of the
negative-parity bands in 156Gd.Comment: presented by Q.T. Doan at XLII Zakopane School of Physics: Breaking
Frontiers: Submicron Structures in Physics and Biology, May 2008. 5 pages,
minor corrections. To be published in the proceeding