Parity-violating pion-nucleon coupling hπNN(1) from π+-electroproton production near the threshold

Abstract

We study the possibility of measuring parity-violating pion-nucleon coupling hπNN(1) from π+-electroproton production in the threshold region. We calculate the electron-helicity asymmetry in terms of hπNN(1) and the Z-boson exchange between the electron and proton in leading-order heavy-baryon chiral perturbation theory. From the result, we demonstrate that the coupling can be determined to an accuracy of ∼ 2 × 10-7 in an experiment with incident electron energy 250 MeV, luminosity 1038 s-1 cm-2, and a running time of 107 s. © 2001 Published by Elsevier Science B.V.