Hyperfine structure of excited state of muonic helium atom

摘要

The recoil, vacuum polarization and electron vertex corrections of first andsecond orders in the fine structure constant $\alpha$ and the ratio of electronto muon and electron to \alpha-particle masses are calculated in the hyperfinesplitting of the $1s^{(e)}_{1/2}2s^{(\mu)}_{1/2}$ state of muonic helium atom(\mu e ^4_2He) on the basis of a perturbation theory. We obtain total resultfor the muonically excited state hyperfine splitting $\Delta \nu^{hfs}=4295.66$MHz which improves previous calculations due to the account of new correctionsand more accurate treatment of the electron vertex contribution.