C. Ciofi Degli Atti

Elastic and quasi-free electron scattering from 12C and projected Hartree-Fock wave functions

Abstract Projected Hartree-Fock wave functions are obtained for 12 C and 11 B using Volkovs force. The elastic electron scattering form factor and the angular and energy distributions for the high-energy 12 C(e, e′p) reaction are calculated. While a good agreement is obtained with the observed elastic form factor only a slight improvement over previous shell-model results is obtained for the quasi-free scattering data. The relatively large deformation of the Hartree-Fock field has only a negligible effect on the calculated form factors.

y-Scaling in quasi-elastic electron scattering by nuclei

y-scaling in quasi-elastic electron scattering from nuclei is discussed paying particular attention to the question of the definition of the scaling variable. By analysing recent experimental data on12C, it is shown that the scaling functionF(y) should be defined in terms of a new scaling variabley1 which takes explicitly into account the effects from finite nuclear masses and nucleon binding; in the asymptotic limity1 goes over into the usual scaling variabley0=Mω/q−q/2. Some open problems concerningy-scaling in3He are also discussed.

Value and limitations of quasi-free electron scattering experiments on atoms

SummarySome very useful information on nuclear structure has been provided by the quasi-free scattering of electrons on nuclei. The quasi-free (e, 2e) experiments on atoms and molecules, which have been proposed recently, have proved to be technically feasible and it is therefore worth-while investigating their value and limitations. The scope of our paper is to show how this line of research will provide new and detailed information on electron wave functions in atoms and eventually also in molecules. It also deals with an important point which has been overlooked in previous papers suggesting these experiments—the way in which the «unavoidable» accidental rate limits the number of states which can be studied. This isnot an experimental problem but lies in the very nature of the reaction itself.RiassuntoGli esperimenti di diffusione quasi-libera di elettroni da nuclei hanno fornito utili informazioni sulla struttura nucleare. Recentemente è stata anche mostrata la possibilità tecnica di realizzare esperimenti di diffusione quasi-libera (e, 2e), proposti quale mezzo di studio della struttura atomica e molecolare. Lo scopo di questo lavoro è di analizzare il valore e i limiti della reazione (e, 2e) e di mostrare come essi possono fornire nuove e dettagliate informazioni sulle funzioni d’onda elettroniche negli atomi ed eventualmente anche nelle molecole. Un problema che è stato trascurato nei precedenti lavori dedicati a tali esperimenti, e cioè la limitazione del numero degli stati che possono venir studiati a causa delle coincidenze casuali inevitabili, viene analizzato in dettaglio, sottolineando che esso non è un problema di carattere sperimentale ma è dovuto alla natura stessa della reazione.РезюмеС помощью рассеяния квази-свободных электронов на атомах была получена некоторая очень полезная информация о ядерной структуре. Квази-свободные (e, 2e) эксперименты на атомах и молекулах, которые были недавно предложены, доказали, что они являются техничесии осуществимыми, и, следова-тельно, необходимо исследовать их значение и ограниченность. Цель нашей статьи-показать, как это направление исследования обеспечит новую и подробную инфор-мацию о электронных волновых функциях в атомах и, в конечном счете, также в молекулах. Также рассматривается важный вопрос, который был отмечен в пре-дыдущих статьях, предлагавших эти эксперименты, о способе, в котором «неиз-бежная» случайная интенсивность ограничивает число состояний, которое может быть изучено. Это составляет не экспериментальную проблему, а лежит в самой природе этой реакции.

Information on nucleon-nucleon interaction from nuclear matter calculations

Recent calculations of Nuclear Matter properties performed within the framework of the Brueckner - Bethe - Goldstone theory and the variational approach based on Jastrow - type wave functions are reviewed. The information that can be gained on the nucleon - nucleon interaction is discussed and the overbinding of Nuclear Matter predicted by the Reid Soft Core interaction is pointed out.