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We present results from an experiment dedicated to measure the lifetimes of the low-lying excited states of 205Bi. This nucleus was studied in the one-proton transfer reaction 204Pb(16O,15N)205Bi and the lifetimes of the 11 / 2 1 - , 7 / 2 1 - , 5 / 2 1 - , 7 / 2 2 - states were determined by utilizing the Recoil Distance Doppler Shift method. Upon comparing the results with the expectations of the particle-core coupling model, it indicates a low quadrupole collectivity in the structure of these states. [ABSTRACT FROM AUTHOR]

We present the results from an experiment dedicated to measure the lifetime of the 2 2 + state, candidate for the one-phonon mixed-symmetry state, of 208 Po. This nucleus was studied in the α -transfer reaction 204 Pb( 12 C, 8 Be) 208 Po and the lifetime of the 2 2 + state was determined by utilizing the Doppler-shift attenuation method. The experimental data show that the 2 2 + state decays with a sizable M1 transition to the 2 1 + state revealing its isovector nature. [ABSTRACT FROM AUTHOR]

The lifetimes of the $ 2^+_1$ , the $ 2^+_2$ and the $ 3^-_1$ states of Po have been measured in the Pb(C,Be)Po transfer reaction by the Doppler-shift attenuation method. The result for the lifetime of the $ 2^+_1$ state is about three times shorter than the adopted value. However, the new value still does not allow for a consistent description of the properties of the yrast $ 2^+_1$ , $ 4^+_1$ , $ 6^+_1$ , and $ 8^+_1$ states of Po in the framework of nuclear shell models. Quasi-particle Phonon Model (QPM) calculations also cannot overcome this problem thus indicating the existence of a peculiarity which is neglected in both theoretical approaches. [ABSTRACT FROM AUTHOR]

fast-timing method to determine lifetimes of nuclear states in the sub-nanosecond domain is presented. It is based on in-beam measurements of triple-gamma coincidences in heavy-ion fusion-evaporation reactions, performed with an array of HPGe and LaBr:Ce detectors. The high-energy resolution HPGe detectors are used to define de-exciting cascades, while the fast LaBr:Ce detectors are used to determine the decay time spectra of selected levels fed by these cascades. A special method to treat the time information of an array of fast detectors is employed in order to fully use the efficiency of the array. Two measurements are presented to illustrate the method: a re-determination of the known half-life $\ensuremath T_{1/2}=0.7$ ns of the $\ensuremath E_x=205$ keV, $\ensuremath J^{\pi}=7/2^+$ level in Cd (test experiment), and the determination of a half-life $\ensuremath T_{1/2}=47$ ps for the $\ensuremath E_x=367$ keV, $\ensuremath J^{\pi}=3/2^+$ state of Tl . [ABSTRACT FROM AUTHOR]