We present a study of high energy photodisintegration of proton-pairs through the γ+He3→p+p+n channel. Photon energies, Eγ, from 0.8 to 4.7 GeV were used in kinematics corresponding to a proton pair ...with high relative momentum and a neutron nearly at rest. The s−11 scaling of the cross section, as predicted by the constituent counting rule for two nucleon photodisintegration, was observed for the first time. The onset of the scaling is at a higher energy and the cross section is significantly lower than for deuteron (pn pair) photodisintegration. For Eγ below the scaling region, the scaled cross section was found to present a strong energy-dependent structure not observed in deuteron photodisintegration.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The charge and magnetic form factors, F-C and F-M, respectively, of He-3 are extracted in the kinematic range 25 fm(-2) <= Q(2) <= 61 fm(-2) from elastic electron scattering by detecting He-3 recoil ...nuclei and scattered electrons in coincidence with the two High Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The measurements find evidence for the existence of a second diffraction minimum for the magnetic form factor at Q(2) = 49.3 fm(-2) and for the charge form factor at Q(2) = 62.0 fm(-2). Both minima are predicted to exist in the Q(2) range accessible by this Jefferson Lab experiment. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the three-body nuclear problem
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
The charge and magnetic form factors, F_{C} and F_{M}, respectively, of ^{3}He are extracted in the kinematic range 25 fm^{-2}≤Q^{2}≤61 fm^{-2} from elastic electron scattering by detecting ^{3}He ...recoil nuclei and scattered electrons in coincidence with the two High Resolution Spectrometers of the Hall A Facility at Jefferson Lab. The measurements find evidence for the existence of a second diffraction minimum for the magnetic form factor at Q^{2}=49.3 fm^{-2} and for the charge form factor at Q^{2}=62.0 fm^{-2}. Both minima are predicted to exist in the Q^{2} range accessible by this Jefferson Lab experiment. The data are in qualitative agreement with theoretical calculations based on realistic interactions and accurate methods to solve the three-body nuclear problem.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
We measured with unprecedented precision the induced polarization P(y) in (4)He(e,e'p)(3)H at Q(2)=0.8 and 1.3 (GeV/c)(2). The induced polarization is indicative of reaction-mechanism effects beyond ...the impulse approximation. Our results are in agreement with a relativistic distorted-wave impulse approximation calculation but are overestimated by a calculation with strong charge-exchange effects. Our data are used to constrain the strength of the spin-independent charge-exchange term in the latter calculation.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UM
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