The weak psuedoscalar coupling of the free and the bound protons

Journal Article · Sun Oct 01 04:00:00 EDT 1995 · Bulletin of the American Physical Society

OSTI ID:255427

Gorringe, T P ^[1]

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1. Univ. of Kentucky, Lexington, KY (United States)

The proton`s weak pseudoscalar coupling, g{sub p} is induced by the effects of its strong interaction on its weak interaction. In the Partially Conserved Axial Current hypothesis g{sub p} is due to single pion exchange between the leptonic and nucleonic currents in semi-leptonic weak processes. It predicts g{sub p} = 8.4 {plus_minus} 0.2 for the free proton but modifications of g{sub p}for the bound proton, due to modifications of the pion field of the bound proton, are possible. We will review the available data on g{sub p} for both the free and the bound proton. In the case of the free proton g{sub p} has been determined from measurements of ordinary (OMC) and radiative muon capture (RMC) on hydrogen. We will discuss the extraction of g{sub p} from the data, the importance of various {mu}-atomic and molecular processes in extracting g{sub p }and compare the results obtained from the OMC and RMC data and experiments in gaseous and liquid H{sub 2}. In the case of the bound proton we will discuss the measurements of ordinary and radiative {mu}{sup -} capture on complex nuclei and the extraction of g{sub p} from these data. The comparison of inclusive RMC and OMC rates on nuclei has led to speculations of a large enhancement of g{sub p} in light nuclei and a large quenching of g{sub p} in heavy nuclei. We will discuss the evidence for and against the renormalization, of g{sub p}in nuclei and the problems of extracting g{sub p} from the nuclear RMC and OMC data.

• OSTI ID: 255427
• Report Number(s): CONF-9510116--
• Journal Information: Bulletin of the American Physical Society, Journal Name: Bulletin of the American Physical Society Journal Issue: 10 Vol. 40; ISSN 0003-0503; ISSN BAPSA6
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
AXIAL-VECTOR CURRENTS
COUPLING
PROTONS
PSEUDOSCALARS
STRONG INTERACTIONS
WEAK INTERACTIONS