R. R. Whitney

Elastic scattering of π+ and π− mesons from 3He and 4He at energies from 300 TO 475 MeV

Abstract The cross section for elastic scattering of pions from 3 He and 4 He was measured for incident energies from 300 to 475 MeV. The pions were detected in a magnetic spectrometer at scattering angles from 30° to 130°. Results on angular distributions are presented. A particularly interesting feature is that a deep minimum at 110°, previously observed at 295 MeV, is found to persist up to 400 MeV. The minimum is fixed in angle and is therefore not a simple function of q 2 .

Trinucleon Threshold Electrodisintegration

Inclusive inelastic electron scattering cross sections for 3H and 3He were measured for excitation energies below 18 MeV. For six values of the three-momentum transfer q in the range 0.88 < q < 2.87 fm−1, longitudinal and transverse response functions were determined. The experimental data are in good agreement with two recent calculations. One uses variational ground-state wave functions and the orthogonal correlated states method to describe the two- and three-body breakup channels. The other uses bound and continuum Faddeev wave functions for a simple central potential. The inclusion of final-state interactions (FSI) in the Faddeev continuum is found to be very important; inclusion of FSI changes the response functions in the threshold kinematics by a large amount, yielding excellent agreement with the data.