Experimental investigation of neutron-nucleon and neutron-deuteron interaction in the energy region 380–590 MeV

Conclusion

A discussion of the experimental material obtained in this work leads to the following conclusions:

• 1) For neutron energy of 380 MeV, the contributions made to neutron-proton interaction by exchange and ordinary forces are approximately equal in magnitude; spin-exchange and spin-non-exchange forces also participate in the exchange interaction of nucleons in about the same degree.

• 2) The differential and total elastic n-p scattering cross-sections weakly vary as the neutron energy varies between 260 MeV and 380 MeV.

• 3) The interaction of neutrons of 380 MeV energy with protons is chiefly of an elastic character. The cross section for meson production at this energy is about 3% of the total n-p interaction cross-section. As the energy increases, the contribution of inelastic processes (meson production) grows rapidly and at Eⁿ = 590 MeV it includes about 25% of σ^t(n-p).

• 4) The data obtained in the study of the interaction of neutrons with energies from 300 to 600 MeV with neutrons and deuterons, testify to the charge symmetry of nuclear forces in this energy region.

• 5) The results of the experiments on the scattering of 380-300 MeV neutrons by nucleons do not contradict the charge invariance of nuclear forces. A qualitative consideration of the experimental data indicates that the inter-actions of nucleons in states with various values of isotopic spin appreciably differ and that the intensity of the interaction in states withT= 0 consider-ably decreases with increase of energy up to 590 MeV.

• 6) The next stage of these investigation, as far as utilization of the hypo-thesis of charge invariance of nuclear forces is concerned, is, in addition to obtaining more precise data on scattering of unpolarized beams of nucleons, the separate determination (in experiments with polarized beams) of the interaction between nucleons in various spin states at a given value ofT.