Localized Excited States of Helium in Liquid Helium

Abstract
Excited atom-like states of helium are shown to exist in stable cavities in liquid helium. A variational model, similar to that used to describe electrons in liquid helium, is employed. It is found that the cavities surrounding these excited atoms are much smaller than in the "free"-electron case. Calculated positions of several atomic lines are found to be in good agreement with measured values.