Chiral O(Q^4) two-body operators for s-wave pion photoproduction on the NN system

Abstract

The two-body currents for s-wave pion photoproduction on the NN system are derived to O(Q^4) in chiral perturbation theory. For the interesting case of 3S1 <-> 1S0 transitions, we show that an axial isovector two-nucleon contact term connects the short-distance physics of pion photoproduction to pion production and several important electroweak reactions. We also find that the standard chiral Lagrangian gives a gamma pi pi N N vertex that have not been explicitly mentioned in previous literature. The corresponding Feynman rule is presented here and some processes where it should be important are briefly discussed.

arXiv comment9 pages, REVTeX, 1 eps figure

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Cited by in corpus (11)

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• Neutron-neutron scattering length from the reaction gamma d --> pi^+ nn employing chiral perturbation theory
• Muon Capture on the Deuteron -- The MuSun Experiment
• Bridging over p-wave pi-production and weak processes in few-nucleon systems with chiral perturbation theory
• Differential cross section and analysing power of the quasi-free pn -> {pp}_s pi- reaction at 353 MeV
• Radiative pion capture in 2H, 3He and 3H
• An update of muon capture on hydrogen
• Pion reactions with few-nucleon systems
• Non-Strange Meson Production with Hadronic Probes