arXiv subjects

R. Anni

Publications and source records attributed to R. Anni.

8 recordsLinked to original sources

arXiv2004

Improved Nearside-Farside Decomposition of Elastic Scattering Amplitudes

A recently proposed technique is described that provides improved nearside-farside (NF) decompositions of elastic scattering amplitudes. The technique, involving a new resummation formula for Legendre partial wave series, reduces the importance of unphysical contributions to NF subamplitudes, which can appear in more conventional NF decompositions. Applications are made to a strong absorption model that arises in chemical and nuclear physics, as well as to a 16O + 16O optical potential at Elab = 132 MeV.

physics.chem-ph↗

arXiv2002

Regularization of Legendre Function Series for Charged Particles Improved Nearside-Farside Subamplitudes

A simple regularization procedure is proposed for the Legendre function series of improved nearside-farside subamplitudes for charged particles elastic scattering. The procedure is the extension of the usual one which defines the partial wave series for the scattering amplitude in the presence of a long range Coulomb term in the potential, and it provides the same convergence rate.

nucl-th↗

arXiv2001

Improved Nearside-Farside Decomposition of Elastic Scattering Amplitudes

A simple technique is described, that provides improved nearside-farside (NF) decompositions of elastic scattering amplitudes. The technique, involving the resummation of a Legendre partial wave series, reduces the importance of unphysical contributions to NF subamplitudes, which can arise in more conventional NF decompositions. Applications are made to a strong absorption model and to a $^{16}$O + $^{12}$C optical potential at $E_{\text{lab}} = 132$ MeV.

nucl-th↗

arXiv2001

Analytical approximation for the sphere-sphere Coulomb potential

A simple analytical expression, which closely approximates the Coulomb potential between two uniformly charged spheres, is presented. This expression can be used in the optical potential semiclassical analyses which require that the interaction be analytic on and near the real r-axis.

nucl-th↗

arXiv2001

Shrinking $\hbar$ as a recipe for revealing classical-like contributions in optical potential cross sections

A simple recipe for revealing classical-like contributions in optical potential cross sections is proposed. The recipe is based on the fact that the classical-like properties are not expected to depend on the actual value of $\hbar$. This allows us to identify the classical-like characteristics of an optical potential cross section by simply repeating the calculation with different values of $\hbar$, and observing which properties of the cross section are invariant. This method is applied to the cross sections of a few optical potentials used to describe the recent data of light heavy-ion elastic scattering.

nucl-th↗

arXiv2000

Airy-like patterns in heavy ion elastic scattering

A semiclassical analysis of an optical potential cross section is presented. The cross section considered is characterized by the appearance of an Airy-like pattern. This pattern is similar to that which is present in many cross sections, which fit the recent measurements of light heavy ion elastic scattering, and is considered as a manifestation of a rainbow phenomenon. The semiclassical analysis shows that, in the case considered, the oscillations arise from the interference between the contributions from two different terms of a multi-reflection expansion of the scattering function, and, therefore, cannot be associated with the rainbow phenomenon.

nucl-th↗

arXiv1995

Mean-field description of nuclear charge density distributions.

We propose a method to extract nuclear charge distributions from elastic electron scattering data based upon a mean field approach. The nuclear charge distributions are generated by solving the Schroedinger equation with a mean-field potential expanded in terms of Hermite functions. The coefficients of the potential are changed in order to obtain the best fit with the cross section data. Applications to the $^{12}C$, $^{16}O$ $^{40}Ca$ and $^{208}Pb$ nuclei are presented.

nucl-th↗

arXiv1994

Nuclear Charge Density Distributions from Elastic Electron Scattering Data

The model independent procedure of extracting charge density distributions from elastic electron scattering data is investigated. The charge density distributions are expanded on an orthonormal basis and the parameters of the expansions are fixed by the comparison with the experimental data. Two bases with different analytical properties (Fourier-Bessel and Hermite) are used. This allows us to disentangle the uncertainties coming from the choice of the expansion basis from those intrinsic to the extraction procedure. We design a set of tests to select the number of the expansion coefficients adequate for a proper description of the data. The procedure is applied to elastic data measured on $^{12}$C, $^{40}$Ca and $^{208}$Pb nuclei.

nucl-th↗