Lifetime measurements of Po and Po with the CTF liquid scintillator detector at LNGS.

We have studied the α-decays of Po into Pb and of Po into Pb tagged by the coincidence with the preceding β-decays from Bi and Bi, respectively. The Rn, Th, and Rn sources used were sealed inside quartz vials and inserted in the Counting Test Facility at the underground Gran Sasso National Laboratory in Italy. We find that the mean lifetime of Po is (236.00 ± 0.42(stat) ± 0.15(syst)) μs and that of Po is (425.1 ± 0.9(stat) ± 1.2(syst)) ns. Our results, obtained from data with signal-to-background ratio larger than 1000, reduce the overall uncertainties and are compatible with previous measurements. [ABSTRACT FROM AUTHOR]