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 $d^j_{m'm}(\theta)$, 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 $L_{max}=3$ are listed in tabular form.Comment: 23 pages revtex including one figure, accepted for 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 $t$-matrix elements a bilinear term of the form $t_{j'}^*t_j$ can be given as a complex linear form in the observables from which an explicit solution for $t_j$ in terms of observables can be obtained. These can also be used to select sets of observables for the explicit representation of the $t$-matrix.Comment: 37 pages revte

Improved (e,e') response functions at intermediate momentum transfers: the 3He case

A possibility of extending the applicability range of non-relativistic calculations of electronuclear response functions in the quasielasic peak region is studied. We show that adopting a particular model for determining the kinematical inputs of the non-relativistic calculations can extend this range considerably, almost eliminating the reference frame dependence of the results. We also show that there exists one reference frame, where essentially the same result can be obtained with no need of adopting the particular kinematical model. The calculation is carried out with the Argonne V18 potential and the Urbana IX three-nucleon interaction. A comparison of these improved calculations with experimental data shows a very good agreement for the quasielastic peak positions at $q=500,$ 600, 700 MeV/c and for the peak heights at the two lower $q$--values, while for the peak height at $q=700$ MeV/c one finds differences of about 20%.Comment: 10 pages, 4 figure

Elektromagnetske odzivne funkcije za nekoliko tijela i Lorentzova integralna transformacija

The Lorentz integral transform method is described briefly. The resulting differential equations are solved via an expansion in hypersherical harmonics, and a new approach is introduced for incorporating correlations in the basis functions. New results for the total photoabsorption cross section of 3H and 3He are presented. It is shown that the peak of the cross section is strongly affected by the three-nucleon force. In addition, we review the results for the 4He electromagnetic response functions obtained with the Lorentz integral transform method.Kratko se opisuje metoda Lorentzove integralne transformacije. Dobiju se diferencijalne jednadžbe koje se rješavaju razvojem po hipersferičnim harmonicima i uvodi se nov pristup radi uključivanja korelacija među osnovnim funkcijama. Prikazuju se novi ishodi računa za ukupni udarni presjek fotoapsorpcije 3H i 3He. Pokazuje se kako na vrh udarnog presjeka jako utječu tro-nukleonske sile. Još se daje pregled ishoda računa za elektromagnetske odzivne funkcije 4He koji su postignuti metodom Lorentzove integralne transformacije

Elektromagnetske odzivne funkcije za nekoliko tijela i Lorentzova integralna transformacija

The Lorentz integral transform method is described briefly. The resulting differential equations are solved via an expansion in hypersherical harmonics, and a new approach is introduced for incorporating correlations in the basis functions. New results for the total photoabsorption cross section of 3H and 3He are presented. It is shown that the peak of the cross section is strongly affected by the three-nucleon force. In addition, we review the results for the 4He electromagnetic response functions obtained with the Lorentz integral transform method.Kratko se opisuje metoda Lorentzove integralne transformacije. Dobiju se diferencijalne jednadžbe koje se rješavaju razvojem po hipersferičnim harmonicima i uvodi se nov pristup radi uključivanja korelacija među osnovnim funkcijama. Prikazuju se novi ishodi računa za ukupni udarni presjek fotoapsorpcije 3H i 3He. Pokazuje se kako na vrh udarnog presjeka jako utječu tro-nukleonske sile. Još se daje pregled ishoda računa za elektromagnetske odzivne funkcije 4He koji su postignuti metodom Lorentzove integralne transformacije

On Complete Sets of Polarization Observables

A new criterion is developed which provides a check as to whether a chosen set of polarization observables is complete with respect to the determination of all independent $T$-matrix elements of a reaction of the type $a+b\to c+d+...$. As an illustrative example, this criterion is applied to the longitudinal observables of deuteron electrodisintegration.Comment: 8 pages revtex, final version, accepted for Nucl. Phys.

Photodisintegration of Three-Body Nuclei with Realistic 2N and 3N Forces

Total photonuclear absorption cross sections of $^3$H and $^3$He are studied using realistic NN and NNN forces. Final state interactions are fully included. Two NN potential models, the AV14 and the r-space Bonn-A potentials, are considered. For the NNN forces the Urbana-VIII and Tucson-Melbourne models are employed. We find the cross section to be sensitive to nuclear dynamics. Of particular interest in this work is the effect which NNN forces have on the cross section. The addition of NNN forces not only lowers the peak height but increases the cross section beyond 70 MeV by roughly 15%. Cross sections are computed using the Lorentz integral transform method.Comment: Results for Bonn potential with model Bonn rA instead of model rB. The Bonn rB results contained a small inexactness. After the correction it turned out that Bonn rA is more suited for our purpose because it leads to a binding energy of 8.15 MeV (about 0.25 MeV more than Bonn rB). In addition the results for the other realistic potentials models are improved at low energies (HH expansion was not completely convergent for the low-energy results). LaTeX, 8 pages, 4 ps figure