Search results for "Faddeev equations"
showing 6 items of 36 documents
Asymmetries in elastic scattering of 100 MeVπ+from a polarizedHe3target
1991
We report the observation of a large asymmetry in the elastic scattering of 100 MeV {pi}{sup +} from a polarized {sup 3}He target. Measurements have been made at laboratory angles of 60{degree}, 80{degree}, and 100{degree}, with the largest value {ital A}{sub {ital y}}=0.89{plus minus}0.12 occurring at 80{degree}, near a cross-section minimum. This asymmetry is the largest observed to date in pion scattering from a spin-1/2 nucleus. The {ital A}{sub {ital y}} data are qualitatively reproduced by a schematic model; however, agreement with the data is significantly improved when realistic three-body Faddeev wave functions and a full nonlocal distorted-wave impulse approximation reaction model…
Study of thepd→pdηreaction
2007
A study of the pd{yields}pd{eta} reaction in the energy range where the recent data from Uppsala are available is done in the two-step model of {eta} production including the final state interaction. The {eta}-d final state interaction is incorporated through the solution of the Lippmann Schwinger equation using an elastic scattering matrix element, T{sub {eta}}{sub d{yields}}{sub {eta}}{sub d}, which is required to be half off-shell. It is written in a factorized form, with an off-shell form factor multiplying an on-shell part given by an effective range expansion up to the fourth power in momentum. The parameters of this expansion have been taken from an existing recent relativistic Fadde…
Description of thef2(1270),ρ3(1690),f4(2050),ρ5(2350), andf6(2510)resonances as multi-ρ(770)states
2010
In a previous work regarding the interaction of two $\ensuremath{\rho}(770)$ resonances, the ${f}_{2}(1270)$ (${J}^{PC}={2}^{++}$) resonance was obtained dynamically as a two-$\ensuremath{\rho}$ molecule with a very strong binding energy, 135 MeV per $\ensuremath{\rho}$ particle. In the present work we use the $\ensuremath{\rho}\ensuremath{\rho}$ interaction in spin 2 and isospin 0 channel to show that the resonances ${\ensuremath{\rho}}_{3}(1690)$ (${3}^{--}$), ${f}_{4}(2050)$ (${4}^{++}$), ${\ensuremath{\rho}}_{5}(2350)$ (${5}^{--}$), and ${f}_{6}(2510)$ (${6}^{++}$) are basically molecules of increasing number of $\ensuremath{\rho}(770)$ particles. We use the fixed center approximation o…
Nucleon Form Factors at high q2 within constituent quark models
2000
The nucleon form factors are calculated using a non-relativistic description in terms of constituent quarks. The emphasis is put on the reliability of present numerical methods used to solve the three-body problem in order to correctly reproduce the expected asymptotic behavior of form factors. Nucleon wave functions obtained in the hyperspherical formalism or employing Faddeev equations have been considered. While a q**(-8) behavior is expected at high q for a quark-quark force behaving like 1/r at short distances, it is found that the hypercentral approximation in the hyperspherical formalism (K=0) leads to a q**(-7) behavior. An infinite set of waves is required to get the correct behavi…
Charmed and Bottom Baryons: a Variational Approach based on Heavy Quark Symmetry
2003
The use of Heavy Quark Symmetry to study bottom and charmed baryons leads to important simplifications of the non-relativistic three body problem, which turns out to be easily solved by a simple variational ansatz. Our simple scheme reproduces previous results (baryon masses, charge and mass radii, $...$) obtained by solving the Faddeev equations with simple non-relativistic quark--quark potentials, adjusted to the light and heavy--light meson spectra. Wave functions, parameterized in a simple manner, are also given and thus they can be easily used to compute further observables. Our method has been also used to find the predictions for strangeness-less baryons of the SU(2) chirally inspire…
Narrow Bound States of the DNN System
2012
We report on a recent calculation of the properties of the $DNN$ system, a charmed meson with two nucleons. The system is analogous to the $\bar K NN$ system substituting a strange quark by a charm quark. Two different methods are used to evaluate the binding and width, the Fixed Center approximation to the Faddeev equations and a variational calculation. In both methods we find that the system is bound by about 200 MeV and the width is smaller than 40 MeV, a situation opposite to the one of the $\bar K NN$ system and which makes this state well suited for experimental observation.