Measurement of the R${}_{LT}$ response function for $\ddot{I}{€}^0$ electroproduction at $Q^2$ = 0.070 (GeV/c)${}^2$ in the $N\to \hat{I}”$ transition}

Abstract

Quadrupole amplitudes in the $γ^{*}N\toΔ$ transition are associated with the issue of nucleon deformation. A search for these small amplitudes has been the focus of a series of measurements undertaken at Bates/MIT by the OOPS collaboration. We report on results from H$(e,e^{\prime }p)\ddot{I}{€}^0$ data obtained at $Q^2=0.070$ (GeV/c)${}^2$ and invariant mass of W=1155 MeV using the out-of-plane detection technique with the OOPS spectrometers. The $\ddot{I}{ƒ}_{LT}$ and $\ddot{I}{ƒ}_T+\hat{I}\mu \cdot$ $\ddot{I}{ƒ}_L$ response functions were isolated. These results, along with those of previous measurements at $W$=1172 MeV and $Q^2=0.127$ (GeV/c)${}^2$, aim in elucidating the interplay between resonant and non resonant amplitudes.