Relativistic Effects in Quasielastic Electron Scattering (original) (raw)
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Physical Review C, 2010
The effects of meson-exchange currents (MEC) are computed for the one-particle one-hole transverse response function for finite nuclei at high momentum transfers q in the region of the quasielastic peak. A semi-relativistic shell model is used for the one-particle-emission (e, e ′) reaction. Relativistic effects are included using relativistic kinematics, performing a semi-relativistic expansion of the current operators and using the Dirac-equation-based (DEB) form of the relativistic mean field potential for the final states. It is found that final-state interactions (FSI) produce an important enhancement of the MEC in the high-energy tail of the response function for q ≥ 1 GeV/c. The combined effect of MEC and FSI goes away when other models of the FSI, not based on the DEB potential, are employed.
Quasielastic electron scattering from nuclei
Annals of Physics, 1980
Inelastic electron scattering is studied in terms of the "characteristic function" F(t), i.e., the Fourier transform of the response function with respect to the energy transfer to the nucleus. Analytic properties of F(t) are discussed as well as moment and cumulant expansions. The latter are particularly useful in the region of the quasielastic peak where the first few characterize position, width and shape of the peak. The dependence of these observables on ground state properties and the final state interaction between ejected nucleon and residual nucleus is calculated for a variety of models. It is shown that the observed shift of the quasielastic peak is related to the exchange parts of the two-body interaction or equivalently to the nonlocality of the optical potential. Semiclassical methods are used to derive a generalized Fermi gas model for inclusive scattering which includes the final state interaction in a simple way. Numerical results are presented for quasielastic electron scattering from 12C A similar description within the framework of a relativistic. nuclear field theory gives surprisingly good agreement with experiment for medium and heavy nuclei and points out the advantages of a relativistic treatment.
Quasielastic Scattering from Relativistic Bound Nucleons: Transverse-Longitudinal Response
Physical Review Letters, 1999
Predictions for electron induced proton knockout from the p 1/2 and p 3/2 shells in 16 O are presented using various approximations for the relativistic nucleonic current. Results for the differential cross section, transverse-longitudinal response (R T L ) and left-right asymmetry A T L are compared at |Q 2 | = 0.8 (GeV/c) 2 corresponding to TJNAF experiment 89-003. We show that there are important dynamical and kinematical relativistic effects which can be tested by experiment.
Physical Review C, 2002
We present theoretical analysis of the first data on the high energy and momentum transfer (hard) quasielastic C(p, 2p)X reactions. The cross section of hard A(p, 2p)X reaction is calculated within the light-cone impulse approximation based on two-nucleon correlation model for the high-momentum component of the nuclear wave function. The nuclear effects due to modification of the bound nucleon structure, soft nucleon-nucleon reinteraction in the initial and final states of the reaction with and without color coherence have been considered. The calculations including these nuclear effects show that the distribution of the bound proton light-cone momentum fraction (α) shifts towards small values (α < 1), effect which was previously derived only within plane wave impulse approximation. This shift is very sensitive to the strength of the short range correlations in nuclei. Also calculated is an excess of the total longitudinal momentum of outgoing protons. The calculations are compared with data on the C(p, 2p)X reaction obtained from the EVA/AGS experiment at Brookhaven National Laboratory. These data show α-shift in agreement with the calculations. The comparison allows also to single out the contribution from short-range nucleon correlations. The obtained strength of the correlations is in agreement with the values previously obtained from electroproduction reactions on nuclei.
International Journal of Modern Physics E, 2015
In this work, we have studied (anti)neutrino induced charged current quasielastic scattering from some nuclear targets in the energy region of Eν < 1 GeV . Our aim is to confront electron and muon production cross sections relevant for νµ ↔ νe orνµ ↔νe oscillation experiments. The effects due to lepton mass and its kinematic implications, radiative corrections, second class currents and uncertainties in the axial and pseudoscalar form factors are calculated for (anti)neutrino induced reaction cross sections on free nucleon as well as the nucleons bound in a nucleus where nuclear medium effects influence the cross section. For the nuclear medium effects we have taken some versions of Fermi gas model(FGM) available in literature. The results for (anti)neutrino-nucleus scattering cross section per interacting nucleons are compared with the corresponding results in free nucleon case. PACS numbers: 12.15.Lk,13.15+g,13.60Rj,21.60.Jz,24.10Cn,been taken into account in the (anti)neutrino Monte Carlo generators like GENIE [36], NEUT [37], NUANCE [38], NuWro [39], GiBUU [40], etc.
Electroweak Nuclear Response in the Quasielastic Regime
Physical Review Letters, 2010
The availability of the double-differential charged-current neutrino cross section, measured by the MiniBooNE collaboration using a carbon target, allows for a systematic comparison of nuclear effects in quasi-elastic electron and neutrino scattering. The results of our study, based on the impulse approximation scheme and a state-of-the-art model of the nuclear spectral functions, suggest that the electron cross section and the flux averaged neutrino cross sections, corresponding to the same target and comparable kinematical conditions, cannot be described within the same theoretical approach using the value of the nucleon axial mass obtained from deuterium measurements. We analyze the assumptions underlying the treatment of electron scattering data, and argue that the description of neutrino data will require a new paradigm, suitable for application to processes in which the lepton kinematics is not fully determined. PACS numbers: 25.30.Pt, 13.15.+g, 24.10.Cn The data set of Charged Current Quasi Elastic (CCQE) events recently released by the MiniBooNE collaboration [1] provides an unprecedented opportunity to carry out a systematic study of the double differential cross section of the process,
AIP Conference Proceedings, 1995
Inclusive quasi-elastic electron scattering o nuclei is investigated at high momentum transfer (Q 2 > 1 (GeV=c) 2) and x > 1 adopting a consistent treatment o f n ucleonnucleon correlations in initial and nal states. It is shown that in case of light a s w ell as complex nuclei the inclusive cross section at 1:3 < x < 2 is dominated by the absorption of the virtual photon on a pair of correlated nucleons and by their elastic rescattering in the continuum, whereas at x > 2 i t i s g o v erned by the rescattering of the outgoing o-mass-shell nucleon in the complex optical potential generated by the ground state of the residual (A-1)-nucleon system.
Inclusive electron scattering from nuclei at x≃1
Physical Review C, 1996
The inclusive A(e, e ′ ) cross section for x ≃ 1 was measured on 2 H, C, Fe, and Au for momentum transfers Q 2 from 1−7 (GeV/c) 2 . The scaling behavior of the data was examined in the region of transition from y-scaling to x-scaling. Throughout this transitional region, the data exhibit ξ-scaling, reminiscent of the Bloom-Gilman duality seen in free nucleon scattering.