75 research outputs found
General Multipole Expansion of Polarization Observables in Deuteron Electrodisintegration
Formal expressions are derived for the multipole expansion of the structure
functions of a general polarization observable of exclusive
electrodisintegration of the deuteron using a longitudinally polarized beam
and/or an oriented target. This allows one to exhibit explicitly the angular
dependence of the structure functions by expanding them in terms of the small
rotation matrices , whose coefficients are given in terms of
the electromagnetic multipole matrix elements. Furthermore, explicit
expressions for the coefficients of the angular distributions of the
differential cross section including multipoles up to are listed in
tabular form.Comment: 23 pages revtex including one figure, accepted for Eur.Phys. J.
New inversion methods for the Lorentz Integral Transform
The Lorentz Integral Transform approach allows microscopic calculations of
electromagnetic reaction cross sections without explicit knowledge of final
state wave functions. The necessary inversion of the transform has to be
treated with great care, since it constitutes a so-called ill-posed problem. In
this work new inversion techniques for the Lorentz Integral Transform are
introduced. It is shown that they all contain a regularization scheme, which is
necessary to overcome the ill-posed problem. In addition it is illustrated that
the new techniques have a much broader range of application than the present
standard inversion method of the Lorentz Integral Transform.Comment: 12 pages. 12 figures, revtex4. submitted to Eur.Phys.J.
Complete Sets of Polarization Observables in Electromagnetic Deuteron Break-up
For deuteron photo- and electrodisintegration the selection of complete sets
of polarization observables is discussed in detail by applying a recently
developed new criterion for the check of completeness of a chosen set of
observables. The question of ambiguities and their resolution by considering
additional observables is discussed for a numerical example, for which the role
of experimental uncertainties is also investigated. Furthermore, by inversion
of the expressions of the observables as hermitean forms in the -matrix
elements a bilinear term of the form can be given as a complex
linear form in the observables from which an explicit solution for in
terms of observables can be obtained. These can also be used to select sets of
observables for the explicit representation of the -matrix.Comment: 37 pages revte
The Lorentz integral transform (LIT) method
The LIT approach is reviewed both for inclusive and exclusive reactions. It
is shown that the method reduces a continuum state problem to a
bound-state-like problem, which then can be solved with typical bound-state
techniques. The LIT approach opens up the possibility to perform ab initio
calculations of reactions also for those particle systems which presently are
out of reach in conventional approaches with explicit calculations of many-body
continuum wave functions. Various LIT applications are discussed ranging from
particle systems with two nucleons up to particle systems with seven nucleons.Comment: Lectures delivered at the 4th DAE-BRNS Workshop on Hadron Physics,
AMU, Aligarh, India, Feb. 18-23, 2008; 23 pages, 16 figure
Incorporation of three-nucleon force in the effective interaction hyperspherical harmonic approach
It is shown how a bare three-nucleon force is incorporated into the formalism
of the effective interaction approach for hyperspherical harmonics. As a
practical example we calculate the ground state properties of 3H and 3He using
the Argonne V18 nucleon-nucleon potential and the Urbana IX three-nucleon
force. A very good convergence of binding energies and matter radii is
obtained. We also find a very good agreement of our results compared to other
high precision calculations.Comment: 17 pages, 3 figure
Lorentz Integral Transform for Inclusive and Exclusive Cross Sections with the Lanczos Method
The Lorentz Integral Transform (LIT) method is reformulated via the Lanczos
algorithm both for inclusive and exclusive reactions. The new technique is
tested for the total photoabsorption cross section of 3H and 4He. Due to the
rapid convergence of the algorithm one has a decrease in cpu time by two orders
of magnitude, but at the same time an excellent agreement with the results of a
conventional LIT calculation. The present work opens up the possibility of ab
initio calculations for inclusive and exclusive processes for A greater equal 6
with inclusion of complete final state interactions.Comment: LaTeX, 13 pages, 3 ps figure
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