29 research outputs found
Description of inclusive scattering of 4.045 GeV electrons from D
We exploit a relationship between the Structure Functions of nucleons, the
physical deuteron and of a deuteron, composed of point-nucleons to compute
angular distributions of inclusive cross sections of 4.05 GeV electrons. We
report general agreement with data and interpret the remaining discrepancies.
We discuss the potential of the data for information on neutron structure
functions and the static form factor .Comment: 9 pages,1 Fig., PS fil
GRS computation of deep inelastic electron scattering on 4He
We compute cross sections for inclusive scattering of high energy electrons
on 4He, based on the two lowest orders of the Gersch-Rodriguez-Smith (GRS)
series. The required one- and two-particle density matrices are obtained from
non-relativistic 4He wave functions using realistic models for the
nucleon-nucleon and three-nucleon interaction. Predictions for E=3.6 GeV agree
well with the NE3 SLAC-Virginia data.Comment: 18 pages, 7 figures, submitted to PR
Exact response of the non-relativistic harmonic oscillator
Using Greens function and operator techniques we give a closed expression
for the response of a non-relativistic system interacting through confining,
harmonic forces. The expression for the incoherent part permits rapid
evaluation of coefficients in a 1/q expansion. A comparison is made with
standard approximation methods.Comment: 9p.; INFN-ISS 93/2; WIS-93/50/Jun-P
Effect of -correlations on predictions of nuclear transparencies for protons, knocked-out in high reactions
We study the transparency of nuclei for nucleons knocked-out in
high-energy semi-inclusive reactions, using an improved theoretical
input, discussed by Nikolaev et al. We establish that neglect of
-correlations between the knocked-out and core nucleons reduces nuclear
transparencies by for light, to for heavy
nuclei. About the same is predicted for transparencies, integrated over the
transverse or longitudinal momentum of the outgoing proton. Hadron dynamics
predicts a roughly constant beyond 2 GeV, whereas for
all targets the largest measured data point =6.7 GeV appears to lie
above that plateau. Large error bars on those data-points preclude a conclusion
regarding the onset of colour transparency.Comment: 12 pages, uuencoded PS files for text and figs.file part1 of 2 part
Beyond the binary collision approximation for the large- response of liquid He
We discuss corrections to the linear response of a many-body system beyond
the binary collision approximation. We first derive for smooth pair
interactions an exact expression of the response , considerably
simplifying existing forms and present also the generalization for interactions
with a strong, short-range repulsion. We then apply the latter to the case of
liquid He. We display the numerical influence of the correction
around the quasi-elastic peak and in the low-intensity wings of the response,
far from that peak. Finally we resolve an apparent contradiction in previous
discussions around the fourth order cumulant expansion coefficient. Our results
prove that the large- response of liquid He can be accurately understood
on the basis of a dynamical theory.Comment: 19 p. Figs. available on reques
Some remarks on off-shell scattering in the eikonal approximation
Using the Abel inversion for the eikonal phase as function of the interaction
we derive simple integral relations between half and on-shell eikonal phases. A
frequently used short-range approximation for the half off-shell phase and
profile appears supported by the above-mentioned relation. We work out some
examples and also address the half off-shell eikonal phase pertinent to a
diffractive amplitude. The latter is relevant for a calculation of selected
transparencies of nuclei for a proton, knocked-out in selected
semi-inclusive (SI) reactions. Some numerical results for are given.Comment: 12 pages, uuencoded PS files for text and fig
Generalized transparency in semi-inclusive processes
It is argued that the transparency of a medium for passage of a nucleon,
knocked-out in a semi-inclusive reaction and subsequently scattered
elastically, is not the same as the one measured in purely elastic scattering.
Expressions are given for the properly generalized transparency and those are
compared with recently proposed, alternative suggestions. Numerical results are
presented for selected nuclear targets and kinematic conditions, applying to
the Garino et al and the SLAC NE18 experiment.Comment: 24p.; added topdraw file for figures; WIS-93/48/Jun-P
Inclusive scattering data on light nuclei as a precision tool for the extraction of G_M^n
We demonstrate that refinements in the analysis of inclusive scattering data
on light nuclei enable the extraction of, generally accurate, values of the
neutron magnetic form factor G_M^n(Q^2). In particular, a recent
parametrization of ep inclusive resonance excitation enables a reliable
calculation of the inelastic background, and as a consequence a separation of
quasi-elastic and inelastic contributions. A far larger number of data points
than previously considered is now available for analysis and enables a more
reliable extraction of G_M^n from cross section and R_T data on D and He. The
achieved accuracy appears mainly limited by the present uncertainties in the
knowledge of proton form factors and by the accuracy of the data.Comment: new version with minor changes in the text and figures, added
references and 5 figure
Predictions for the 4 GeV TJNAF inclusive electron scattering experiment and for FSI effects in EMC ratios
We express nuclear structure functions as generalized convolutions of
the structure function of a nucleon and of a nucleus, composed of
point-nucleons. In computations of the latter we include Final State
Interactions and results for are compared with a few directly measured
data on C and Fe. The above are primarily used for predictions of the
TJNAF 89-008 inclusive scattering experiment of 4 GeV electrons on various
targets. Those cover a broad angular, and correspondingly wide range,
where the nucleon-inelastic part dominates large sections of the covered
kinematics. The same model has been applied to the study of hitherto neglected
Final State Interaction effects in the nuclear component in EMC ratios in the
region .Comment: 12 page
Final state effects on superfluid He in the deep inelastic regime
A study of Final State Effects (FSE) on the dynamic structure function of
superfluid He in the Gersch--Rodriguez formalism is presented. The main
ingredients needed in the calculation are the momentum distribution and the
semidiagonal two--body density matrix. The influence of these ground state
quantities on the FSE is analyzed. A variational form of is used, even
though simpler forms turn out to give accurate results if properly chosen.
Comparison to the experimental response at high momentum transfer is performed.
The predicted response is quite sensitive to slight variations on the value of
the condensate fraction, the best agreement with experiment being obtained with
. Sum rules of the FSE broadening function are also derived and
commented. Finally, it is shown that Gersch--Rodriguez theory produces results
as accurate as those coming from other more recent FSE theories.Comment: 20 pages, RevTex 3.0, 11 figures available upon request, to be appear
in Phys. Rev.