arXiv subjects

O. Benhar

Publications and source records attributed to O. Benhar.

40 records · Page 3Linked to original sources

arXiv1996

Glauber theory of initial- and final-state interactions in (p,2p) scattering

We develop the Glauber theory description of initial- and final-state interactions (IFSI) in quasielastic A(p,2p) scattering. We study the IFSI-distortion effects both for the inclusive and exclusive conditions. In inclusive reaction the important new effect is an interaction between the two sets of the trajectories which enter the calculation of IFSI-distorted one-body density matrix for inclusive (p,2p) scattering and are connected with incoherent elastic rescatterings of the initial and final protons on spectator nucleons. We demonstrate that IFSI-distortions of the missing momentum distribution are large over the whole range of missing momentum both for inclusive and exclusive reactions and affect in a crucial way the interpretation of the BNL data on (p,2p) scattering. Our numerical results show that in the region of missing momentum $p_{m}\lsim 100-150$ MeV/c the incoherent IFSI increase nuclear transparency by 5-10\%. The incoherent IFSI become dominant at $p_{m}\gsim 200$ MeV/c.

nucl-th↗

arXiv1995

The longitudinal asymmetry of the $(e,e'p)$ missing momentum distribution as a signal of color transparency

We use multiple scattering theory to evaluate the $Q^{2}$ dependence of the forward-backward asymmetry, $A_{z}$, of the missing momentum distribution in quasielstic $A(e,e'p)$ scattering, which is expected to be affected by color transparency. The novel features of our analysis are a consistent treatment of the structure of the ejectile state formed after absorption of the virtual photon by the struck proton and a careful evaluation of the background asymmetry induced by the nonvanishing real part of the proton-nucleon scattering amplitude. We find that the absolute magnitude of $A_{z}$ is dominated by this background at the $Q^{2}$'s attainable at the Continuous Electron Beam Accelerator Facility. However, the $Q^{2}$ dependence of the asymmetry is sensitive to the onset of color transparency, whose observation in high statistics experiments appears to be feasible, particularly using light targets such as $^{12}C$ or $^{16}O$.

nucl-th↗

arXiv1995

Accidental $ξ$-scaling as a Signature of Nuclear Effects at $x>1$

We propose an interpretation of the $ξ$-scaling behavior of nuclear structure functions observed at Bjorken $x>1$ and $Q^2 \lesssim 4 \, {\rm (GeV/c)^2}$. We show that at $ξ\gtrsim 1$, $ξ$-scaling might arise accidentally because of the approximate cancellation of two different $Q^2$-dependent effects, namely Final State Interactions and the effects implicit in the choice of the scaling variable $ξ$. We provide a new convolution formula for the nuclear structure function in terms of $ξ$ and make predictions for the kinematical regions where Final State Interactions are expected to be small and the suggested balancing of scaling violations is expected to break down. Our analysis is aimed at the final goal of clarifying the range of applicability of local duality ideas in nuclei.

hep-ph↗

arXiv1995

Can a Highly Virtual Nucleon Experience Final State Interactions in Electron-Nucleus Scattering?

We discuss how the virtuality of the struck particle may affect the final state interactions in electron-nucleus scattering. The extent to which short range correlations inhibit rescattering taking place within the range of the repulsive core of the NN interaction is quantitatively analyzed. The possible modifications of the nucleon-nucleon scattering amplitude associated with the virtuality is also studied, within the framework of a nonrelativistic model. The results suggest that the on shell approximation can be safely employed in the kinematical region relevant to the analysis of the available inclusive data at large momentum transfer and low energy loss.

hep-ph↗