The 12C(p,2p)l1B reaction has been measured at 100 MeV in both symmetric and asymmetric geometries. Distorted wave impulse approximation calculations were used to obtain spectroscopic factors for all states of l1B below 7 MeV excitation. From these spectroscopic factors and the shapes of the measured angular correlations, it is concluded that (i) no large 1f components are present in the wavefunction of the ground state of 12C and (ii) this experiment gives no evidence for the formation of giant resonances as the intermediate step in multistep reaction processes to the 4·44 MeV (5/2-) and 6·74 MeV (7/2-) states of 11B.

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4 -states of 16 0 at excitation energies of 17·79 and 19·80 MeV (T = 0) and 18·98 MeV (T = 1) are observed to be strongly excited in inelastic scattering of 135 MeV protons at momentum transfers of 200-500 MeV/c. The previous ambiguity in the spin and parity assignments for the 17·79 MeV state is removed.Excitation of stretched particle-hole 6-states has been observed (Adams et al. 1977) in the inelastic scattering of intermediate energy protons on 24Mg and 2sSi. The predominant configuration in these 6-states was assumed to be If 7 / 2 (1d s / 2 )-1, and the measured differential cross sections were successfully interpreted in terms of this configuration.In I p-shell nuclei the maximum angular momentum achievable by a single particle-hole excitation is 4 -, in a Id s / 2 (l P3/2) -1 excitation. Only two 4-states in 16 0 have been confirmed in transfer reactions (MairIe et al. 1978); a third state was observed but definite spin and parity assignments could not be made. The present work was undertaken in an attempt to observe these states in a (p, p') reaction at 135 MeV bombarding energy and to attempt to clarify the existence of a third 4-state.The incident beam of 135MeV protons, which was obtained from the Indiana University Cyclotron Facility (IUCF), bombarded a 10 mgcm -2 Mylar (C 10 H s 0 4 ) target. The carbon contribution was measured by bombardment of a polystyrene target ((CH)n) of similar thickness, and the oxygen contribution was obtained by subtraction of spectra.The inelastically scattered protons were detected with the QDDM magnetic spectrograph of the IUCF, to which the beam analysis system and beam line were dispersion matched. The excitation energy bite at the focal plane of the spectrograph was about 6t MeV, and the spectrograph was set to cover the excitation region from 14 to 20·5 MeV in 16 0. The focal plane detector system was composed ofa helical delay-line gas counter for position measurement (Officer et al. 1975), followed by two plastic scintillators. The differential energy loss of detected particles in the two scintillators was used in particle identification; a triple coincidence from the detectors was required. Overall resolution for most of the spectra was about 80 keV FWHM.

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