Chiral vibrations and collective bands in Mo-104,Mo-106

High spin states of the neutron-rich Mo-104 nucleus have been reinvestigated by analyzing the gamma rays in the spontaneous fission of Cf-252 with Gammasphere. Both gamma-gamma-gamma and gamma-gamma-gamma-gamma coincidence data were analyzed. A new Delta I = 1 band has been discovered with a tentative 5(-) band head, and is proposed to form a class of chiral vibrational doublets with another 4(-) band previously found. Angular correlation measurements have been performed to determine the spins and parities. A new 3(-) level has been added to one of the chiral doublet bands in Mo-106. The origin of the chiral doublet bands in Mo-104,Mo-106 is interpreted as a neutron h(11/2) particle and mixed d(5/2), g(7/2) hole coupled to the short and long axis, respectively. Triaxial projected shell model calculations have been performed for the chiral doublet bands in Mo-104,Mo-106. The results show reasonably good agreement with the experimental data.