I wrote: Unfortunately I don't have any other details and don't know of a particular > experiment to refer to. Here is the quote from a textbook I recently > finished reading: ... >
It was late last night, and the paragraph I found and quoted pertained to deuterium, not 4He, which you were asking about, Bob. I recall reading that 4He does not have an excited state either, but I will have to see if I can find where I saw that (it might also have been a mistaken impression). Eric
