Shift and broadening of resonance lines of antiprotonic helium atoms in liquid 4He

摘要

The shift and broadening of the resonance lines in the spectrum of antiprotonic helium atoms p?He~+ located in fluid and superfluid 4He have been estimated. The contributions to the shift and broadening from collective degrees of freedom in liquid 4He have been evaluated using the phenomenological response function. The shift due to collisions of p?He~+ with 4He atoms has been calculated in the quasistatic limit using the experimental pair-correlation function. It has been shown that an implanted p?He~+ atom establishes a good probe of liquid-helium properties, since this atom practically does not change the target structure.