Gurung L, Babij T J, Hogan S D, Cassidy D B
Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, United Kingdom.
Phys Rev Lett. 2020 Aug 14;125(7):073002. doi: 10.1103/PhysRevLett.125.073002.
We report a new measurement of the positronium (Ps) 2^{3}S_{1}→2^{3}P_{0} interval. Slow Ps atoms, optically excited to the radiatively metastable 2^{3}S_{1} level, flew through a microwave radiation field tuned to drive the transition to the short-lived 2^{3}P_{0} level, which was detected via the time spectrum of subsequent ground state Ps annihilation radiation. After accounting for Zeeman shifts we obtain a transition frequency ν_{0}=18501.02±0.61 MHz, which is not in agreement with the theoretical value of ν_{0}=18498.25±0.08 MHz.
我们报告了对正电子素（Ps）的(2^{3}S_{1}\to2^{3}P_{0})能级间隔的一项新测量。慢正电子素原子被光激发到辐射亚稳的(2^{3}S_{1})能级，然后穿过一个调谐到驱动向短寿命(2^{3}P_{0})能级跃迁的微波辐射场，通过随后基态正电子素湮灭辐射的时间谱来检测该跃迁。在考虑塞曼频移后，我们得到跃迁频率(\nu_{0}=18501.02\pm0.61) MHz，这与理论值(\nu_{0}=18498.25\pm0.08) MHz不一致。
