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C. Ciofi degli Atti

Publications and source records attributed to C. Ciofi degli Atti.

67 records · Page 4Linked to original sources
arXiv1996

Tagging nucleon structure functions by heavy particle detection in deep inelastic electron-ion scattering

It is shown that in deep inelastic electron - ion collisions the detection, in coincidence with the scattered electron, of a nucleus A-1 in the ground state, as well as a nucleon and a nucleus A-2 also in the ground state, may provide unique information on several long standing problems, such as the origin of the EMC effect, the possible medium modifications of the nucleon structure functions, and the nature of Nucleon-Nucleon correlations.

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arXiv1996

On the Extraction of the Neutron Spin Structure Functions and the Gerasimov -- Drell -- Hearn Integral from $^3\vec {He}(\vec e, e')X$ data

Nuclear effects in polarized inelastic electron scattering off polarized $^3He$ are discussed; in the kinematics of future experiments at CEBAF, Fermi motion effects are found to be much larger than in deep inelastic scattering. It is shown that improperly describing nuclear dynamics would lead to the extraction of unreliable neutron spin structure functions. On the other hand side, a simple and workable equation relating the Gerasimov -- Drell -- Hearn Integral for the neutron to the corresponding quantity for $^3He$ is proposed.

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arXiv1996

Spin Structure Function of the Deuteron in the Resonance Region and the GDH Sum Rule for the Neutron

The nuclear effects in the spin-dependent structure function $g_1$ of the deuteron are studied in the kinematics of future experiments at CEBAF, ($ν\leq 3~GeV, ~Q^2 \leq 2~GeV^2$). The magnitude of the nuclear effects is found to be significantly larger than the one occurring in deep inelastic scattering ($ν\to \infty, ~Q^2\to \infty$). We discuss the mechanism leading to large effects in the region of the nucleon resonances. A possibility to measure the neutron structure functions in the CEBAF experiments with deuterium is analysed, and conclusions about the experimental study of the $Q^2$ dependence of the Gerasimov-Drell-Hearn Sum Rule for the neutron are drawn.

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arXiv1996

The Neutron Spin Structure Function from the Deuteron Data in the Resonance Region

Nuclear effects in the spin-dependent structure function $g_1$ of the deuteron are studied in the kinematics of future experiments at CEBAF, ($ν\leq 3~GeV, ~Q^2 \leq 2~GeV^2$). The magnitude of nuclear effects is found to be significantly larger than the one occurring in deep inelastic scattering ($ν\to \infty, ~Q^2\to \infty$). A possibility to measure the neutron structure functions in the CEBAF experiments with deuterium is analysed. It is found that disregarding or improperly treating nuclear effects in the region of nucleon resonances would lead to the ``extraction" of an unreliable function. A procedure aimed at correctly extracting the neutron structure function from the deuterium data is illustrated and conclusions about the experimental study of the $Q^2$ dependence of the Gerasimov-Drell-Hearn Sum Rule for the neutron are drawn.

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arXiv1995

Realistic Model of the Nucleon Spectral Function in Few- and Many- Nucleon Systems

By analysing the high momentum features of the nucleon momentum distribution in light and complex nuclei, it is argued that the basic two-nucleon configurations generating the structure of the nucleon Spectral Function at high values of the nucleon momentum and removal energy, can be properly described by a factorised ansatz for the nuclear wave function, which leads to a nucleon Spectral Function in the form of a convolution integral involving the momentum distributions describing the relative and center-of-mass motion of a correlated nucleon-nucleon pair embedded in the medium. The Spectral Functions of $^3He$ and infinite nuclear matter resulting from the convolution formula and from many-body calculations are compared, and a very good agreement in a wide range of values of nucleon momentum and removal energy is found. Applications of the model to the analysis of inclusive and exclusive processes are presented, illustrating those features of the cross section which are sensitive to that part of the Spectral Function which is governed by short-range and tensor nucleon-nucleon correlations.

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arXiv1994

Investigation of the Neutron Form Factors by Inclusive Quasi-Elastic Scattering of Polarized Electrons off Polarized $^{3}$He: A Theoretical Overview

The theory of quasi-elastic inclusive scattering of polarized leptons off polarized $^3$He is critically reviewed and the origin of different expressions for the polarized nuclear response function appearing in the literature is explained. The sensitivity of the longitudinal asymmetry upon the neutron form factors is thoroughly investigated and the role played by the polarization angle for minimizing the proton contribution is illustrated.

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arXiv1994

Nucleon-Nucleon Correlations and Six-Quark Cluster Effects in Semi-Inclusive Deep Inelastic Lepton Scattering off Few-Nucleon Systems

Semi-inclusive deep inelastic lepton scattering off few-nucleon systems is investigated assuming that virtual boson absorption occurs on a hadronic cluster which can be either a two-nucleon correlated pair or a six-quark bag. In both cases the relevance of nuclear effects on forward and backward nucleon emissions is illustrated and the differences expected in the energy distribution of the emitted nucleons are analyzed both at x>1 and x<1.

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arXiv1994

The Spin-Dependent Structure Functions of Nuclei in the Meson-Nucleon Theory

A theoretical approach to the investigation of spin-dependent structure functions in deep inelastic scattering of polarized leptons off polarized nuclei, based on the effective meson-nucleon theory and operator product expansion method, is proposed and applied to deuteron and $^3He$. The explicit forms of the moments of the deuteron and $^3He$ spin-dependent structure functions are found and numerical estimates of the influence of nuclear structure effects are presented.

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arXiv1994

Nucleon-Nucleon Correlations and Final State Interaction in Inclusive Quasi-Elastic Electron Scattering off Nuclei at x>1

Inclusive quasi-elastic electron scattering off nuclei is investigated at high momentum transfer (Q^2>1 (GeV/c)^2) and x>1 adopting a consistent treatment of nucleon-nucleon correlations in initial and final states. It is shown that in case of light as well as complex nuclei the inclusive cross section at 1.3 2 it is governed by the rescattering of the outgoing off-mass-shell nucleon in the complex optical potential generated by the ground state of the residual (A-1)-nucleon system.

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arXiv1993

Nuclear effects in Deep Inelastic Scattering of polarized electrons off polarized 3He and the neutron spin structure functions

It is shown that the nuclear effects playing a relevant role in Deep Inelastic Scattering of polarized electrons by polarized $^3$He are mainly those arising from the effective proton and neutron polarizations generated by the $S'$ and $D$ waves in $^3$He. A simple and reliable equation relating the neutron, $g_1^n$, and $^3$He, $g_1^3$, spin structure functions is proposed. It is shown that the measurement of the first moment of the $^3$He structure function can provide a significant check of the Bjorken Sum Rule.

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