Том 88, № 3 (2025)

The angular correlation function of a finite particle y and a g-quantum is used to analyze the angular distribution of g-radiation, which removes the excitation of the nucleus, formed in a nuclear reaction. The experimental and calculated angular distributions of g-radiation during the deexcitation of the 12C(2+) nucleus in inelastic scattering of deuterons and neutrons are compared. In the inelastic scattering of deuterons with an energy of 15.3 MeV, the analysis was performed using the experimental and calculated values of the spin tensors of the 12C(2+) density matrix, determined by us earlier. In the inelastic scattering of neutrons with an energy of 14.1 MeV, the experimental angular distribution of g-quanta (TANGRA collaboration) is compared with that calculated on the basis of spin tensors defined in the coupled-channel method. The normalized angular distributions of g-quanta in the scattering of both deuterons and neutrons are consistent with the experimental ones. It is shown that the anisotropy of g-radiation in inelastic neutron scattering is 1.5 times higher than the anisotropy in inelastic deuteron scattering.

The e+e− →p0γ cross section has been measured in the center-of-mass energy range from 1000 to 1060 MeV with the SND detector at the VEPP-2000 e+e− collider. At the maximum of the φ(1020) resonance the systematic uncertainty of the cross section measurement is 1.3%, and the statistical uncertainty is 2.2%. To date this is the most accurate measurement of the e+e− →p0γ cross section. As a result of data approximation with the vector dominance model the decay probability B(φ→p0γ )= (1.452 ± 0.024 ± 0.067)×10−3 has been measured.