Measuring the p-odd pion-nucleon coupling h(pi NN)((1)) in pi(+)-photoproton production near threshold

Authors
Citation
Jw. Chen et Xd. Ji, Measuring the p-odd pion-nucleon coupling h(pi NN)((1)) in pi(+)-photoproton production near threshold, PHYS REV L, 86(19), 2001, pp. 4239-4242
Citations number
39
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW LETTERS
ISSN journal
00319007 → ACNP
Volume
86
Issue
19
Year of publication
2001
Pages
4239 - 4242
Database
ISI
SICI code
0031-9007(20010507)86:19<4239:MTPPCH>2.0.ZU;2-R
Abstract
We show that <(<gamma>)over right arrow>p --> pi (+)n in the threshold regi on is an excellent candidate fur measuring the leading parity-violating pio n-nucleon coupling h(pi NN)((1)) to an uncertainty of 20% if it has a natur al size from dimensional analysis. The conclusion is based on a large unpol arized cross section, a new low-energy theorem for the photon polarization asymmetry at the threshold A(gamma)\(th) = root2 f(pi)(mu (p) - mu (n))h(pi NN)((1))/g(A)m(N) similar to h(pi NN)((1))/2 and its strong dominance at f orward and backward angles in the threshold region.