Atomic approaches in metastable antiprotonic helium atoms. REPLY to 'analysis of the lifetimes and fractions of antiprotons trapped in metastable antiprotonic-helium states' by I. Shimamura and M. Kimura

摘要

In the present note the authors clarify the purpose of YO and complement its essential points, thus showing that the criticisms of SK are inappropriate. The paper YO (1) was aimed at discussing some new aspects related to the metastability of hadronic helium atoms which had been discovered when negative kaons (2), negative pions (3) and antiprotons (4) were stopped in liquid helium. The delayed fraction, time spectrum shape and lifetimes were the observables. Further experimental studies are in progress (5), and as of today there is no successful explanation for these interesting phenomena. So, YO tried to give brief and rather qualitative estimates for the observations in an intuitive way, considering only the leading terms. The following problems are discussed in as simple a manner as possible, starting from the exotic-atom viewpoints of Condo (6) and Russell (7): (i)the atomic core polarization effect, (ii)the structure and radiative lifetimes, (iii)the non-statistical distribution of the angular momentum and an estimate of the delayed fraction, and (iv)the isotope effect, though the title represents only (i). To respond to the comments of SK, it is important to consider the correspondence between the atomic approach and the molecular approach for the metastable antiprotonic helium atom of Condo-Russell. We therefore begin this note with a discussion of this aspect. (author). (ERA citation 20:008970)