Single pion contribution to the hyperfine splitting in muonic hydrogen

A detailed discussion of the long-range one-pion exchange (Yukawa potential) contribution to the 2S hyperfine splitting in muonic hydrogen, which had, until recently, been disregarded, is presented. We evaluate the relevant vertex amplitudes, in particular [pi] super(0)[mu] super(+)[mu] super(-), combining low energy chiral expansions together with experimental data on [pi] super(0) and [eta] decays into two leptons. A value of (ProQuest: Formulae and/or non-USASCII text omitted) is obtained for this contribution.