Ordinary and radiative muon capture on the proton and the pseudoscalar form factor of the nucleon
| العنوان: | Ordinary and radiative muon capture on the proton and the pseudoscalar form factor of the nucleon |
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| المؤلفون: | Véronique Bernard, Ulf-G. Meißner, Thomas R. Hemmert |
| المصدر: | Nuclear physics / A 686, 290-316 (2001). doi:10.1016/S0375-9474(00)00520-0 |
| بيانات النشر: | North-Holland Publ. Co., 2001. |
| سنة النشر: | 2001 |
| مصطلحات موضوعية: | Nuclear and High Energy Physics, Particle physics, Chiral perturbation theory, Nuclear Theory, radiative capture [muon- p], Feynman graph, FOS: Physical sciences, pseudoscalar [form factor], form factor [nucleon], energy spectrum [photon], charged current, chiral effective field theory, Nuclear Theory (nucl-th), Pion, High Energy Physics - Phenomenology (hep-ph), interpretation of experiments [numerical calculations], Effective field theory, Radiative transfer, ddc:530, Nuclear Experiment (nucl-ex), ordinary and radiative muon capture pseudoscalar form factor, Nuclear Experiment, capture [muon- p], Physics, chiral [symmetry], effective Lagrangian, Form factor (quantum field theory), Muon capture, Pseudoscalar, High Energy Physics - Phenomenology, Nucleon |
| الوصف: | 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 effective field theories only employed pion and nucleon degrees of freedom and were not able to reproduce the photon spectrum in the pioneering experiment of radiative muon capture on the proton from TRIUMF. For the past few years it has been speculated that the discrepancy between theory and experiment might be due to Delta(1232) related effects, which are only included via higher order contact interactions in the standard chiral approach. In this report we demonstrate that this speculation does not hold true. We show that contrary to expectations from naive dimensional analysis isobar effects on the photon spectrum and the total rate in radiative muon capture are of the order of a few percent, consistent with earlier findings in a more phenomenological approach. We further demonstrate that both ordinary and radiative muon capture constitute systems with a very well behaved chiral expansion, both in standard chiral perturbation theory and in the small scale expansion, and present some new ideas that might be at the bottom of the still unresolved discrepancy between theory and experiment in radiative muon capture. Finally we comment upon the procedure employed by the TRIUMF group to extract new information from their radiative muon capture experiment on the pseudoscalar form factor of the nucleon. We show that it is inconsistent with the ordinary muon capture data. 22 pp, RevTeX, uses epsf, 8 figs, enlarged version, discussion of ordinary muon capture on protons substantially enlarged, accepted for publication in Nucl.Phys.A, FZJ-IKP(TH)-2000-02 |
| اللغة: | English |
| DOI: | 10.1016/S0375-9474(00)00520-0 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::72d194f90b0c8cd03abda294c301f8fd https://hdl.handle.net/2128/10751 |
| Rights: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....72d194f90b0c8cd03abda294c301f8fd |
| قاعدة البيانات: | OpenAIRE |
| DOI: | 10.1016/S0375-9474(00)00520-0 |
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