Theoretical Investigation of Some Doubly Excited States of Helium

The origin of the plus and minus character of the ${}_{}{}^1{}_{}{}^{}P$ and ${}_{}{}^3{}_{}{}^{}P$ doubly excited states of helium which converge to the $n=2\mathrm{}$ level is investigated in the close-coupling approximation. It is found that the close-coupling wave functions do exhibit the plus and minus character, and that the widths of these states are related to their plus and minus character in the case of the ${}_{}{}^1{}_{}{}^{}P$, but not for ${}_{}{}^3{}_{}{}^{}P$.