Parity-violating asymmetry in the nucleon to delta transition: A Study of Inelastic Electron Scattering in the G0 Experiment

The parity-violating asymmetry arising from inelastic electron scattering at backward angle (∼ 95??) near the Delta resonance has been measured for both hydrogen and deuterium targets as part of the G 0 experiment. For Q2 = 0.34 (GeV/c) 2 and W = 1.18 GeV, the asymmetries were found to be AHinel=-33.4+/-5 .3stat+/-5 .1sysppm, ADinel=-43.6+/-1 4.6stat+/- 6.2sysppm. .;From the hydrogen asymmetry, the axial transition form factor, GAND , can be extracted. GAND is related to probability of the quark spin-flip that occurs as the proton transitions to the Delta. From the measured asymmetry, the form factor is found to be GAND=-0.046+/- 0.35stat+/- 0.34sys+/- 0.06theory. .;Though GAND has been previously studied using charged current reactions, the G0 measurement represents the first measurement of the asymmetry in the neutral weak sector. These findings agree within errors with the theoretical predictions.