1. Measurement of the Parity-Violating Asymmetry in Inclusive Electroproduction ofπ−near theΔ0Resonance
- Author
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V. Tadevosyan, M. Stutzman, M. K. Jones, R. Suleiman, J. Hansknecht, G. Guillard, Fatiha Benmokhtar, Darko Androić, S. Kox, W. D. Ramsay, Michael Pitt, W. T. H. van Oers, J. Roche, T. Horn, A. Micherdzinska, S. L. Bailey, E. Voutier, D. T. Spayde, H. Breuer, P. Bosted, Douglas H Beck, G. Flores, Christophe Furget, Michael Gericke, S. Wells, R. D. McKeown, Neven Simicevic, M. Muether, M. Poelker, E. J. Beise, Y. C. Chao, D. Gaskell, A. Coppens, M. Versteegen, J. Grames, B. P. Quinn, D. S. Armstrong, G. R. Smith, M. Mihovilovic, Junyu Liu, C. L. Capuano, L. Bimbot, S. E. Williamson, J. Birchall, S. K. Phillips, Wolfgang Korsch, Juliette Mammei, S. A. Wood, P. M. King, J. Arvieux, S. F. Pate, H. Mkrtchyan, C. Ellis, S. A. Page, P. G. Roos, P. Pillot, G. B. Franklin, W. F. Vulcan, T. Seva, J. Schaub, L. Lee, V. Papavassiliou, J. W. Martin, Jay Benesch, J. S. Real, C. A. Davis, and A. Lung
- Subjects
Physics ,Particle physics ,Chiral perturbation theory ,010308 nuclear & particles physics ,Scattering ,media_common.quotation_subject ,Hyperon ,General Physics and Astronomy ,Inelastic scattering ,01 natural sciences ,Asymmetry ,Nuclear physics ,Pion ,0103 physical sciences ,High Energy Physics::Experiment ,Neutron ,Nuclear Experiment ,010306 general physics ,Electron scattering ,media_common - Abstract
The parity-violating (PV) asymmetry of inclusive π- production in electron scattering from a liquid deuterium target was measured at backward angles. The measurement was conducted as a part of the G0 experiment, at a beam energy of 360 MeV. The physics process dominating pion production for these kinematics is quasifree photoproduction off the neutron via the Δ^0 resonance. In the context of heavy-baryon chiral perturbation theory, this asymmetry is related to a low-energy constant d_Δ^- that characterizes the parity-violating γNΔ coupling. Zhu et al. calculated d_Δ^- in a model benchmarked by the large asymmetries seen in hyperon weak radiative decays, and predicted potentially large asymmetries for this process, ranging from A_γ^-=-5.2 to +5.2 ppm. The measurement performed in this work leads to A_γ^-=-0.36±1.06±0.37±0.03 ppm (where sources of statistical, systematic and theoretical uncertainties are included), which would disfavor enchancements considered by Zhu et al. proportional to V_(ud)/V_(us). The measurement is part of a program of inelastic scattering measurements that were conducted by the G0 experiment, seeking to determine the N-Δ axial transition form factors using PV electron scattering.
- Published
- 2012
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