We address the issue of nuclear attenuation in nucleon and pion knockout reactions. A selection of results from a model based on a relativistic multiple-scattering approximation is presented. We show transparency calculations for pion electroproduction on several nuclei, where data are in very good agreement with calculations including color transparency. Secondly, we discuss the density dependence of reactions involving one or double proton knockout. The latter reaction succeeds in probing the high density regions in the deep interior of the nucleus.
A relativistic model for quasielastic (QE) lepton-nucleus scattering is presented. The effects of final-state interactions (FSI) between the ejected nucleon and the residual nucleus are described in the relativistic Green's function (RGF) model where FSI are consistently described with exclusive scattering using a complex optical potential. The results of the model are compared with experimental results of electron and neutrino scattering.
A Practical Method for Relativistic 3N-Scattering Calculations with Realistic Potentials
利用动量空间的尺度变换,从非相对论势生成一个相位等效相对论势。通过这种变换,本文介绍了一种用真实核子-核子势计算相对论3 N散射的实用方法。这种形式可以应用于任何现实的非相对论势。我们还讨论了自由相对论性三体格林函数的移动对数奇点的位置。它进入相对论性3 N Faddeev方程,该方程很久以前已经为3玻色子束缚态制定,我们建议也用于3 N散射。最后,我们比较了相对论性和非相对论性的氘核波函数。
Relativistic models developed for the exclusive and inclusive QuasiElastic (QE) electron scattering have been extended to Charged-Current (CC) and Neutral-Current (NC) neutrino-nucleus scattering. The results of different descriptions of Final-State Interactions (FSI) are compared.
Electron scattering is an effective method to study the nuclear structure. For the odd-$A$ nuclei with proton holes in the outmost orbits, we investigate the contributions of proton holes to the nuclear quadrupole moments $Q$ and magnetic moments $μ$ by the multiple Coulomb scattering and magnetic scattering. The deformed nuclear charge densities are constructed by the relativistic mean-field (RMF) models. Comparing the theoretical Coulomb and magnetic form factors with the experimental data, the nuclear quadrupole moments $Q$ and nuclear magnetic moments $μ$ are investigated. From the electro…
Relativistic models developed for the exclusive and inclusive quasielastic (QE) electron scattering have been extended to charged-current (CC) and neutral-current (NC) neutrino-nucleus scattering. Different descriptions of final-state interactions (FSI) are compared. For the inclusive electron scattering the relativistic Green's function approach is compared with calculations based on the use of relativistic purely real mean field potentials in the final state. Both approaches lead to a redistribution of the strength but conserving the total flux. Results for the differential cross section at …
Reaction cross sections of carbon isotopes for proton scattering are calculated in large energy region. Density distributions of carbon isotopes are obtained from relativistic mean field results. Calculations are based on two procedures: the Glauber theory and relativistic impulse approximation, and results are compared with each other as well as with experimental data. A strong relationship between reaction cross section and root-mean-square radius is clearly shown for 12C using a model distribution.
In the frame work of relativistic mean field (RMF) theory, we calculate the density distribution of protons and neutrons for $^{40,42, 44,48}Ca$ with NL3 and G2 parameter sets. The microscopic proton-nucleus optical potential for $p+^{40,42,44,48}Ca$ system is evaluated from Dirac NN-scattering amplitude and the density of the target nucleus using Relativistic-Love-Franey and McNeil-Ray-Wallace parametrizations. Then we estimate the scattering observables, such as elastic differential scattering cross-section, analyzing power and the spin observables with relativistic impulse approximation. We…
The analysis of the recent experimental data on charged-current neutrino-nucleus scattering cross sections measured at MiniBooNE requires fully relativistic theoretical descriptions also accounting for the role of final state interactions. In this work we evaluate inclusive quasielastic differential neutrino cross sections within the framework of the relativistic impulse approximation. Results based on the relativistic mean field potential are compared with the ones corresponding to the relativistic Green function approach. An analysis of scaling and superscaling properties provided by both mo…
An analysis of inclusive quasielastic electron scattering is presented using different descriptions of the final state interactions within the framework of the relativistic impulse approximation. The relativistic Green's function approach is compared with calculations based on the use of relativistic purely real mean field potentials in the final state. Both approaches lead to a redistribution of the strength but conserving the total flux. Results for the differential cross section at different energies are presented. Scaling properties are also analyzed and discussed.
Relativistic models developed for the exclusive and inclusive quasielastic (QE) electron scattering have been extended to charged-current (CC) and neutral-current (NC) neutrino-nucleus scattering. Different descriptions of final-state interactions (FSI) are compared. For the inclusive electron scattering the relativistic Green's function approach is compared with calculations based on the use of relativistic purely real mean field potentials in the final state. Both approaches lead to a redistribution of the strength but conserving the total flux. Results for the differential cross section at …
The scattering phase-shifts are invariant under unitary transformations of the Hamiltonian. However, the numerical solution of the scattering problem that requires to discretize the continuum violates this phase-shift invariance among unitarily equivalent Hamiltonians. We extend a newly found prescription for the calculation of phase shifts which relies only on the eigenvalues of a relativistic Hamiltonian and its corresponding Chebyshev angle shift. We illustrate this procedure numerically considering $ππ$, $πN$ and $NN$ elastic interactions which turns out to be competitive even for small nu…
The elastic backward proton-deuteron scattering is analyzed including relativistic effects in the deuteron and the mechanism of this reaction which includes the graphs corresponding to the emission, rescattering and absorption of the virtual pion by a deuteron nucleon in addition to the one-nucleon exchange graph. It allows one to obtain a rather satisfactory description of all the experimental data on the differential cross section, tensor analyzing power of the deuteron and transfer polarization in this reaction.
We provide a parametrization of a new phenomenological scaling function obtained from a chi-square fit to a selected set of (e,e') cross section data expanding a band centered around the quasielastic peak. We start from a re-analysis of quasielastic electron scattering from nuclear matter within the relativistic mean field model. The cross section depends on the relativistic effective mass of the nucleon, $m_N^*$, and it scales with respect to a new scaling variable, $ψ^*$. This suggests a new superscaling approach with effective mass (SuSAM*) for predicting quasielastic cross sections within …
Using the covariant spectator theory and the transversity formalism, the unpolarized, coincidence cross section for deuteron electrodisintegration, $d(e,e'p)n$, is studied. The relativistic kinematics are reviewed, and simple theoretical formulae for the relativistic impulse approximation (RIA) are derived and discussed. Numerical predictions for the scattering in the high $Q^2$ region obtained from the RIA and five other approximations are presented and compared. We conclude that measurements of the unpolarized coincidence cross section and the asymmetry $A_ϕ$, to an accuracy that will distin…
We have analyzed pion-nucleon scattering using the manifestly relativistic covariant framework of Infrared Regularization up to {\cal O}(q^3) in the chiral expansion, where q is a generic small momentum. We describe the low-energy phase shifts with a similar quality as previously achieved with Heavy Baryon Chiral Perturbation Theory, \sqrt{s}\lesssim1.14 GeV. New values are provided for the {\cal O}(q^2) and {\cal O}(q^3) low-energy constants, which are compared with previous determinations. This is also the case for the scattering lengths and volumes. Finally, we have unitarized the previous …
We study the impact of the description of the knockout nucleon wave function on electron- and neutrino-induced quasielastic and single-pion production cross sections. We work in a fully relativistic and quantum mechanical framework, where the relativistic mean-field model is used to describe the target nucleus. The focus is on Pauli blocking and the distortion of the final nucleon, these two nuclear effects are separated and analyzed in detail. We find that a proper quantum mechanical treatment of these effects is crucial to provide the correct magnitude and shape of the inclusive cross sectio…
Models developed within the framework of the relativistic impulse approximation for quasielastic (QE) electron and neutrino-nucleus scattering are discussed. Different descriptions of final-state interactions (FSI) in the inclusive scattering are compared: the relativistic Green's function (RGF) and the relativistic mean field (RMF).The results of the models are compared with the recently measured double-differential charged-current QE (CCQE) neutrino MiniBooNE cross sections.
A model based on the relativistic impulse approximation for quasielastic lepton-nucleus scattering is presented. The effects of the final-state interactions (FSI) between the emitted nucleon and the residual nucleus are described by the relativistic Green's function model where FSI are treated consistently with the exclusive scattering and using the same complex optical potential. The results of the model are compared with the results of different descriptions of FSI and with available data for neutrino-nucleus scattering.
We discuss the formulation of the scattering asymptotic condition in a relativistic quantum theory formulated in terms of reflection positive Euclidean Green functions.
We consider quantum inverse scattering with singular potentials and calculate the Sine-Gordon model effective potential in the laboratory and centre-of-mass frames. The effective potentials are frame dependent but closely resemble the zero-momentum potential of the equivalent Ruijsenaars-Schneider model.
Two relativistic approaches to charged-current quasielastic neutrino-nucleus scattering are illustrated and compared: one is phenomenological and based on the superscaling behavior of electron scattering data and the other relies on the microscopic description of nuclear dynamics in relativistic mean field theory. The role of meson exchange currents in the two-particle two-hole sector is explored. The predictions of the models for differential and total cross sections are presented and compared with the MiniBooNE data.