arXiv subjects

Giampaolo Co'

Publications and source records attributed to Giampaolo Co'.

25 records · Page 2Linked to original sources

arXiv2002

A model for two-proton emission induced by electron scattering

A model to study two-proton emission processes induced by electron scattering is developed. The process is induced by one-body electromagnetic operators acting together with short-range correlations, and by two-body $Δ$ currents. The model includes all the diagrams containing a single correlation function. A test of the sensitivity of the model to the various theoretical inputs is done. An investigation of the relevance of the $Δ$ currents is done by changing the final state angular momentum, excitation energy and momentum transfer. The sensitivity of the cross section to the details of the correlation function is studied by using realistic and schematic correlations. Results for $^{12}$C, $^{16}$O and $^{40}$Ca nuclei are presented.

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arXiv2001

Correlations and charge distributions of medium heavy nuclei

The effects of long- and short-range correlations on the charge distributions of some medium and heavy nuclei are investigated. The long-range correlations are treated within the Random Phase Approximation framework and the short-range correlations with a model inspired to the Correlation Basis Function theory. The two type of correlations produce effects of the same order of magnitude. A comparison with the empirical charge distribution difference between 206Pb and 205Tl shows the need of including both correlations to obtain a good description of the data.

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arXiv2000

Short-range correlations in low-lying nuclear excited states

The electromagnetic transitions to various low-lying excited states of 16O, 48Ca and 208Pb are calculated within a model which considers the short-range correlations. In general the effects of the correlations are small and do not explain the required quenching to describe the data.

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arXiv2000

Correlated model for quasi-elastic responses in finite nuclear systems

A model to calculate nuclear responses considering short-range correlation effects is presented. The model is applied to the study of electromagnetic responses induced by one-body operators. We calculate one- and two-nucleon emission responses and cross sections of the 16O and 40Ca nuclei in the quasi-elastic region, and we compare them with experimental data.

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arXiv2000

Spin-orbit interaction in Hartree-Fock calculations

The contribution of the spin-orbit interaction in Hartree-Fock calculations for closed shell nuclei is studied. We obtain explicit expressions for the finite range spin-orbit force. New terms with respect to the traditional spin-orbit expressions are found. The importance of the finite-range is analyzed. Results obtained with spin-orbit terms taken from realistic interactions are presented. The effect of the spin-orbit isospin dependent terms is evaluated.

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arXiv1998

Tensor interaction in Hartree--Fock calculations

The contribution of the tensor interaction in Hartree-Fock calculations for closed shell nuclei is studied. The investigation is done neglecting the spin-orbit component of the force. As expected from nuclear matter estimates we find that the effect of the tensor interaction is negligible in the case of spin-isospin saturated nuclei and also for medium and heavy nuclei with closed shells. In light nuclei with only one of the two spin- orbit partners filled, such as 12C and 14C, the tensor interaction plays an important role.

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arXiv1997

Two-nucleon emission in the longitudinal response

The contribution of the two-nucleon emission in the longitudinal response for inclusive electron scattering reactions is studied. The model adopted to perform the calculations is based upon Correlated Basis Function theory but it considers only first order terms in the correlation function. The proper normalization of the wave function is ensured by considering, in addition to the usually evaluated two-point diagrams, also the three-point diagrams. Results for the 12C nucleus in the quasi-elastic region are presented.

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