Measurement of the induced pseudoscalar coupling via radiative muon capture on hydrogen

摘要

The hydrogen atom is the most fundamental lepton-hadron system and it has been used very extensively to test our theories of the electroweak interaction. Muonic hydrogen, (mu)(sup -)p, is the next most fundamental atom and therefore it can also be used to test and extend our basic knowledge of the electroweak interaction between leptons and quarks. Both the ordinary muon capture (OMC) reaction, (mu)(sup -)p (yields) (nu)(sub (mu))n, and the radiative muon capture (RMC) reaction, (mu)(sup -)p (yields) (nu)(sub (mu))n(gamma), are sensitive to gp, the induced pseudoscalar coupling constant of the semi-leptonic interaction. However, RMC is considerably more sensitive to gp because of the much larger range of momentum transfers which can occur in the RMC reaction. For the highest photon energies the RMC pseudoscalar amplitude is enhanced by more than a factor of three. A status report and preliminary results from TRIUMF Experiment 452, radiative muon capture on hydrogen, are presented in this paper. (author). 24 refs., 9 figs. (Atomindex citation 27:058536)