Determining the lifetime of the 5s5p3P0o metastable state in 87Sr from the electric dipole matrix element

We report a measurement of the radiative lifetime of the 5s5p 3P0o metastable state in 87Sr, which is coupled to the 5s2 1S0 ground state via a hyperfine -induced electric dipole transition. The radiative lifetime is determined to be 151.4(48) s, in good agreement with theoretical results. Our approach relies on accurate measurements of laser intensity and free -space Rabi frequency, enabling lifetime measurements of any excited state and particularly suitable for long-lived states.