Charge form factor and vacuum polarization corrections to the μ^- rate in³He

The form factor analysis by Schiff of electron-tri-nucleon scattering data and the dipole nucleon form factors are used to obtain the charge density function for³He. This is employed, along with the vacuum polarization contribution, to calculate a reliable finite size correction to μ^--meson capture rates in³He. We find a reduction of 3.43% from the commonly used value for the muon density inside the nucleus calculated from the nonrelativistic wave function for a point charge. Incorporation of the present corrections into previous theoretical μ^- analyses leads to strengthening of Oakes' conclusion on the preference of the Irving over the Irving-Gunn form of the three-nucleon wave function and brings one of the induced tensor coupling constant values found by Bietti into agreement with the recent work of Fearing which yielded g _T ^(ω) ≳35 g _v ^(ω) .