Photonuclear reactions at intermediate energies

Total and Differential Cross-Sections of 16O(γ,n)3Heα8Be0 Reaction

“…Однак i до теперiшнього часу немає однозначної вiдповiдi на запитання про ме-ханiзм видалення нуклона з ядра. Розрахунки в нерелятивiстському наближеннi [1][2][3][4] привели до висновку, що механiзм прямого вибивання не мо-же пояснити як величину перерiзу ( , )-реакцiї, так i однаковий вигляд кутових розподiлiв в ( , )-i ( , )-реакцiях. Визнано, що основний внесок дає процес взаємодiї -кванта з нуклонною парою в момент обмiну нуклонiв мезоном.…”

Radiative capture of polarized neutrons by12C in the energy rangeE n=20?35 MeV

“…It may be noted that in [6] a broad E2 resonance centered at 26 MeV and having a width of 4 MeV was used in the input to the calculations. Experiments on elastic photon scattering by 12C [17, 18-1 yielded evidence for an E2 continuum, having almost constant strength for photon energies between 26 and 36 MeV.…”

“…The contributions are parametrized in terms of the optical potential in which the incident nucleon moves, and a form factor describing its coupling to the appropriate collective multipole excitation of the capturing nucleon system. At excitation energies above the giant resonance region, a different approach to radiative nucleon capture has been used by Hebach et al [6]. The authors decompose the transition matrix into different physical processes which represent the contributions from (i) the "direct" shell model transition, (it) the nucleon correlations in the initial and final states, and (iii) the gauge, or exchange, contributions due to the direct coupling of the electromagnetic field to the correlations between a neutron and a proton.…”

Interpretation of the High-Energy ProcessesO16(γ,Schoch1 1978Phys. Rev. Lett.77040View full textAdd to dashboardCite

“…3 * 4 A promising approach, which gives a good description of the data below the meson threshold, is a model with a one-pion-exchange force. 5 In this model the photon is absorbed mainly by a correlated neutron-proton pair; it is similar to the quasideuteron model used for the description of (y ,np) processes or other processes, e.g., 4 He(y,j!<j). 6 In this Letter it is demonstrated by using the quasideuteron model, that the form factor of the residual nucleus plays an essential role in the interpretation of the measured data in a wide energy range.…”