Study of Few-Nucleon Systems with the CEBAF Large Acceptance Spectrometer

Abstract

The study of few‐nucleon systems at intermediate energies is an important aspect of the nuclear‐physics program carried out by the CLAS Collaboration at Jefferson Laboratory. Our investigations aim at understanding the nuclear dynamics at short distances, the transition from hadronic to partonic description of nuclei, and how nuclei can be described in the framework of Quantum Chromodynamics. Our data on photodisintegration of 3He and 4He at beam energies from 0.3 GeV to 1.5 GeV strongly favor theoretical calculations that include three‐body mechanisms and indicate significant contributions of these mechanisms at large momentum transfer, especially in the range of photon energies from 0.6 GeV to 0.8 GeV. Our investigations of exclusive and inclusive electron scattering off nuclear targets have yielded the determination of the ratio of pp to pn correlated pairs in 3He and of the probabilities of short‐range correlations in nuclei. We have studied the transition from hadronic to partonic dynamics in nuclear processes by searching for the onset of scaling of the invariant cross sections of photoinduced reactions on few‐nucleon systems. Our data are consistent with scaling at momentum transfer as low as 1 (GeV/c)2.