skip to main content

DOE PAGESDOE PAGES

Title: Measurement of the parity-violating asymmetry in inclusive electroproduction of π- near the Delta0 resonance

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 quasi-free photoproduction off the neutron via the Δ0 resonance. In the context of heavy-baryon chiral perturbation theory (HBχPT), this asymmetry is related to a low energy constant dΔ- that characterizes the parity-violating γNΔ coupling. Zhu et al. calculated dΔ- in a model benchmarked by the large asymmetries seen in hyperon weak radiative decays, and predicted potentially large asymmetries for this process, ranging from Aγ- = -5.2 to +5.2 ppm. The measurement performed in this work leads to Aγ- = -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 Vud/Vus. 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.
Authors:
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; « less
Publication Date:
OSTI Identifier:
1038247
Report Number(s):
JLAB-PHY--12-1479; DOE/OR/23177--1997; arXiv:1112.1720
Journal ID: ISSN 0031-9007; PRLTAO; TRN: US1201833
Grant/Contract Number:
AC05-06OR23177
Type:
Accepted Manuscript
Journal Name:
Physical Review Letters
Additional Journal Information:
Journal Volume: 108; Journal Issue: 12; Journal ID: ISSN 0031-9007
Publisher:
American Physical Society (APS)
Research Org:
Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)
Sponsoring Org:
USDOE Office of Science (SC)
Contributing Orgs:
G0 Collaboration
Country of Publication:
United States
Language:
English
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; ASYMMETRY; DEUTERIUM TARGET; ELECTRONS; ELECTROPRODUCTION; FORM FACTORS; HYPERONS; INELASTIC SCATTERING; NEUTRONS; PERTURBATION THEORY; PHOTOPRODUCTION; PHYSICS; PIONS; PRODUCTION; RADIATIVE DECAY; RESONANCE; SCATTERING