Date of Award
Program or Major
Doctor of Philosophy
The partial cross-sections sigmaLT, sigmaTT, and sigmaT+&egr;sigmaL have been measured for the H(e, e'pi+)n reaction, at Q 2 = 0.127 (GeV/c)2, W = 1232 MeV and theta piq = 44.45°, in a recent experiment at the MIT/Bates Linear Accelerator Center. The experiment was done with the Bates Out Of Plane Spectrometer system (OOPS) using a high duty factor (>50%) 950 MeV unpolarized electron beam. The One Hundred Inch Proton Spectrometer (OHIPS) detected electrons, and three OOPS modules provided out of plane hadron detection in two sequential sets of simultaneous measurements. The sigmaLT partial cross section is sensitive to the coulombic quadrupole amplitude C2, and can be used to extract the ratio (CMR) of C2 to the dominant magnetic dipole (M1) amplitude, and sigmaTT is similarly sensitive to the electric quadrupole (E2) amplitude and can be used to evaluate the E2 to M1 ratio (EMR). These measurements in the pi+ channel complement pi0 channel measurements of the same responses which were made during the same experiment; the different sensitivities to background terms in the two charge channels will provide increased precision in the CMR and EMR extraction, and permit isospin decomposition of the multipoles.
Kirkpatrick, John M., "Measurement of the partial cross-sections sigmaTT, sigmaLT and sigmaT + epsilon-sigmaL of the p(e,e'pion+)n reaction at the Delta(1232) resonance" (2006). Doctoral Dissertations. 319.