2000/11/30 by Jiunn-Wei Chen, Xiangdong Ji · 23 citations
Mathematics · Physics and Astronomy · #Atomic and Molecular Physics #Combinatorics #Coupling (piping) #Mathematics #Nuclear physics research studies #Nucleon #Particle physics #Physics #Pion #Polarization (electrochemistry) #Quantum Chromodynamics and Particle Interactions #hep-ph #nucl-ex #nucl-th
paper · pdf · doi:10.1103/physrevlett.86.4239
published in Physical Review Letters 86(19), 4239-4242 (American Physical Society) · 4 pages, 3 figures. More data points in fig. 1 and note added in proof added
arxiv created 2001/02/13 · openalex publication_date 2001/05/07 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We show that \stackrel\ensuremath→\ensuremathγp\ensuremath→\ensuremathπ+n in the threshold region is an excellent candidate for measuring the leading parity-violating pion-nucleon coupling h_\ensuremathπNN(1) to an uncertainty of 20% if it has a natural size from dimensional analysis. The conclusion is based on a large unpolarized cross section, a new low-energy theorem for the photon polarization asymmetry at the threshold A_\ensuremathγ|th\phantom\rule0ex0ex=\phantom\rule0ex0ex√(2)f_\ensuremathπ(\ensuremathμp\ensuremath-\ensuremathμn)h_\ensuremathπNN(1)/gAmN\ensuremath∼h_\ensuremathπNN(1)/2, and its strong dominance at forward and backward angles in the threshold region.