Measurement of the Parity-Violating Asymmetry in Inclusive Electroproduction of π- near the Δ0 Resonance
- Creators
- Androić, D.
- Liu, J.
- McKeown, R. D.
- G0 Collaboration
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.
Additional Information
© 2012 American Physical Society. Received 7 December 2011; published 20 March 2012. We gratefully acknowledge the strong technical contributions to this experiment from many groups: Caltech, Illinois, LPSC-Grenoble, IPN-Orsay, TRIUMF and particularly the Accelerator and Hall C groups at Jefferson Lab. CNRS (France), DOE (U.S.), NSERC (Canada) and NSF (U.S.) supported this work in part.Attached Files
Published - Androic2012p17777Phys_Rev_Lett.pdf
Files
Name | Size | Download all |
---|---|---|
md5:b6aaf9deb248d0f7b82bb11833e56778
|
190.3 kB | Preview Download |
Additional details
- Eprint ID
- 30120
- Resolver ID
- CaltechAUTHORS:20120417-084735860
- CNRS (France)
- Department of Energy (DOE)
- NSERC (Canada)
- NSF
- Created
-
2012-04-17Created from EPrint's datestamp field
- Updated
-
2021-11-09Created from EPrint's last_modified field