Related papers: Radiative Muon Capture and Induced Pseudoscalar Co…
The recent TRIUMF experiment for $\mu^- p \to n \nu_{\mu} \gamma$ gave a surprising result that the induced pseudoscalar coupling constant $g_P$ was larger than the value obtained from $\mu^- p \to n \nu_{\mu}$ experiment as much as 44 %.…
The recent TRIUMF experiment for $\mu^- p \to n \nu_{\mu} \gamma$ gave a surprising result that the induced pseudoscalar coupling constant $g_P$ was larger than the value obtained from $\mu^- p \to n \nu_{\mu}$ experiment as much as 44 %.…
The induced pseudoscalar coupling $g_p$ is the least well known of the weak coupling constants of the proton's charged--current interaction. Its size is dictated by chiral symmetry arguments, and its measurement represents an important test…
The first measurement of the elementary process $\mu^- p \rightarrow \nu_{\mu} n \gamma$ is reported. A photon pair spectrometer was used to measure the partial branching ratio ($2.10 \pm 0.22) \times 10^{-8}$ for photons of k > 60 MeV. The…
In a recent preprint Cheon and Cheoun have derived from a chiral model an additional term, not usually appearing in the standard matrix element for radiative muon capture. Using that term they generate a large correction to the RMC spectrum…
It has recently been claimed by Cheon and Cheoun that the discrepancy between the experimental value of the induced pseudoscalar g_P, obtained at TRIUMF from a measurement of the radiative muon capture by proton, and its value predicted by…
The singlet capture rate $\Lambda_S$ for the semileptonic weak process $\mu+p \to n+\nu_\mu$ has been measured in the MuCap experiment. The novel experimental technique is based on stopping muons in an active target, consisting of a time…
We report a measurement of the ortho-para transition rate in the p$\mu$p molecule. The experiment was conducted at TRIUMF via the measurement of the time dependence of the 5.2 MeV neutrons from muon capture in liquid hydrogen. The…
The rate of nuclear muon capture by the proton has been measured using a new experimental technique based on a time projection chamber operating in ultra-clean, deuterium-depleted hydrogen gas at 1 MPa pressure. The capture rate was…
The first measurement of the radiative muon capture (RMC) rate on a proton was recently carried out at TRIUMF. The TRIUMF group analyzed the RMC rate in terms of the theoretical formula of Beder and Fearing, and found the surprising result…
We calculate the imaginary part of the induced pseudoscalar form factor of the nucleon $G_P(t)$ in the framework of two-loop heavy baryon chiral perturbation theory. The effect of the calculated three-pion continuum on the pseudoscalar…
Angular distribution of neutrinos (recoil nucleus) in muon capture for an allowed Gamov-Teller transition is considered by taking account of hyperfine effects. This angular distribution is shown to include a correlation of the form P_2(cos…
Beta-decay and muon-capture experiments in nuclei are reviewed. The conserved vector current hypothesis is confirmed through the observed constancy of the vector coupling constant determined from the superallowed Fermi transitions and from…
The hyperfine effect in muon capture rate is analyzed with taking into account of the second-order terms in 1/M in the non-relativistic Hamiltonian. It is shown that in the situation of the dominance of the squared first-order terms the…
We survey a new generation of precision muon lifetime experiments. The goal of the MuCap experiment is a determination of the rate for muon capture on the free proton to 1 percent, from which the induced pseudoscalar form factor $g_P$ of…
The question of pseudovector versus pseudoscalar coupling schemes for the kaon-hyperon-nucleon interaction is re-examined for the reaction $\gamma p\to K^+ \Lambda$ in several isobaric models. These models typically include Born terms,…
We calculate ordinary and radiative muon capture on the proton in an effective field theory of pions, nucleons and delta isobars, working to third and second order in the small scale expansion respectively. Preceding calculations in chiral…
We present an extension of the QCD sum rule method in the external fields so as to determine the induced pseudoscalar coupling constant g_P, which tests the validity of the partially conserved axial current (PCAC) hypothesis. This is…
By measuring the lifetime of the negative muon in pure protium (hydrogen-1), the MuCap experiment determines the rate of muon capture on the proton, from which the proton's pseudoscalar coupling g_p may be inferred. A precision of 15% for…
The role of the suppression of the coupling constant in the pseudovector pion-nucleon interaction is examined to account for the calculation of the magnetic moment of nucleon. Among three kinds of the higher-order corrections the vacuum…