[en] Test results are described on three inexpensive 5-inch photomultiplier tubes of Venetian-blind construction to be used for collection of Cherenkov light produced by electromagnetic showers in lead glass. Parameters evaluated include photoelectron collection efficiency, pulse-height resolution, amplitude and rate stability, and linearity

[en] The experiment consisted of measurements in coincidence with π⁰ (using the π⁰ spectrometer) and the proton (using a special proton arm built for this experiment). The experimenters finished taking data by the last cycle of 1984. The reaction ¹⁶O(π⁺,π⁰p) was measured at T/sub π/=165 and 245 MeV for the π⁰ angles between 30 and 130⁰. At each angle the protons were detected by using an array of plastic scintillator telescopes, which covered the quasi-free angular-correlation region. Although the data are still being analyzed, preliminary results for the first run indicate that the quasi-free process (a knock-out of a p-shell nucleon) can be identified. When analysis is complete, we hope that it will either confirm the model suggested or shed new light on the process

[en] Experimentally measured angular distributions are presented for the reactions ¹³C(π⁺,π⁰)¹³N (IAS) and ⁷Li(π⁺,π⁰)⁷Be (g.s. + 0.429 MeV) at T/sub π/ = 150 MeV. The data were obtained with the π⁰ spectrometer. The experimental cross sections are larger than calculations, by factors of 2 to 3. Also presented are the excitation function for ¹³C(π⁺,π⁰)¹³N (IAS) at theta = 5⁰ for T/sub π⁺/ = 70 MeV to 180 MeV. The data do not agree with calculations. All our present differential cross sections seem to be consistent with previously measured angle-integrated cross sections. 11 references

[en] Precision measurements are presented of the proton electric to magnetic form-factors ratios at Q² = 0.3 - 0.8 (GeV/c)², obtained by polarization-transfer in Hall A of the Jefferson Laboratory. The measured ratios are significantly lower than published values. New global fits to the individual form factors indicate a lower electric form factor and a slightly higher magnetic form factor. The proton charge radius extracted from the new results is somewhat smaller but consistent with previous values obtained from electron-proton scattering, and is in significant disagreement with the recent value obtained from muonic hydrogen. The effects of the new results on other quantities are briefly discussed. (author)

[en] We studied the reactions ³He(e, e'p)d and ³He(e, e'p)pn in quasi-elastic perpendicular, co-planar kinematics. The transferred energy and momentum were fixed at 840 MeV and 1502 MeV/c respectively. The cross sections were measured up to missing momenta above 1000 MeV/c. For the two-body break-up channel, the A_TL asymmetry was measured up to missing momentum of 660 MeV/c. The data are compared to several model calculations and demonstrate an intricate interplay between reaction dynamics and nuclear structure

[en] We discuss the first coincidence measurements of the reaction (π⁺,π⁰p). The were performed primarily on /sup 16/O at T/sub π//sub =/ = 165 and 245 MeV. The reaction is shown to have a clear quasi-free signature. The π⁰ energy spectra for events corresponding to removal of a p-shell nucleon are compared to predictions of Δ-hole model calculations; the calculation generally underestimate the (π⁺, π⁰p) cross sections. At forward pion angles experimental ratios between the (π⁺, π⁺p) and (π⁺, π⁰p) reactions are found to differ significantly from estimates using free π-N cross sections. A study of the A-dependence of the (π⁺, π⁰p) process indicate that the cross section is roughly constant over the examined range of nuclear masses

No abstract available

[en] This presentation includes a review of the available data on response functions in the ²H(e,e'p)n reaction. In a set of new measurements, high quality data on the interference response functions have been obtained, and are described here. A discussion of several future measurements is also presented. High quality data on the response functions is essential for the characterization of the electromagnetic currents in the deuteron. (orig.)

[en] The interaction of 70-MeV positive and negative pions with s-d shell nuclei was studied with the prompt gamma technique. The results are discussed in terms of cascade-evaporation calculations

[en] The interaction of 70-MeV positive and negative pions with s-d shell nuclei was studied via measurements of the deexcitation γ rays from residual nuclei produced in the reactions. Cross sections for producing specific levels in the residual nuclei were measured. The results are compared with Monte Carlo calculations of intranuclear cascades, followed by evaporation processes. In order to take into account the special features of the prompt γ-ray technique, the probability for leaving the residual nuclei at different regions of excitation, together with measured γ-ray branching ratios, are incorporated into the calculated cross sections. Good agreement is found between measured and calculated cross sections for reactions involving the removal of four or more nucleons. For such reactions, the calculations are dominated by pion absorption processes. The cross sections for the removal of an α-equivalent cluster from tT = 0 nuclei have about the same strength as those corresponding to the removal of a triton cluster from the neighboring T = 1/2 nuclei. This suggests that the final nucleus, rather than the removed particle, is mainly responsible for the observed strength. The cross sections for single-nucleon-removal reactions do not agree with the calculations