40 research outputs found
Two- and three-alpha systems with nonlocal potential
Two body data alone cannot determine the potential uniquely, one needs
three-body data as well. A method is presented here which simultaneously fits
local or nonlocal potentials to two-body and three-body observables. The
interaction of composite particles, due to the Pauli effect and the
indistinguishability of the constituent particles, is genuinely nonlocal. As an
example, we use a Pauli-correct nonlocal fish-bone type optical model for the
potential and derive the fitting parameters such that it
reproduces the two- and three- experimental data.Comment: 16 pages, 5 figures, Inverse Scattering Conference, Aug 2007, Siofok,
Hungary New reference adde
Cluster structures in Oxygen isotopes
Cluster structure of 16O,18O and 20O is investigated by the antisymmettrized
molecular dynamics (AMD) plus generator coordinate method (GCM). We have found
the K^{\pi}=0 and 0 rotational bands of 18O that have the prominent
14C+\alpha cluster structure. Clustering systematics becomes richer in 20O. We
suggest the K^{\pi}=0 band that is the mixture of the 12C+\alpha+4n and
14C+6He cluster structures, and the K^{\pi}=0 band that has the 14C+6He
cluster structure. The K^{\pi}=0 and 0 bands that have the
prominent 16C+\alpha cluster structure are also found.Comment: 9pages, 9figure
Realistic ghost state: Pauli forbidden state from rigorous solution of the α particle
The antisymmetrization of the composite particles in cluster model calculations manifests itself in Pauli forbidden states (ghost states), if one restricts oneself to an undeformed cluster in the low-energy region. The resonating group method and the generating coordinate method rely on a property of the norm kernel, which introduces some of the ghost states. The norm kernel has been usually been calculated under the assumption that the inner wave functions have a simple Gaussian form. This is the first time that this assumption has been tested in a rigorous way. In the 4He+N system, we demonstrate a ghost state, which is calculated from a rigorous solution of Yakubovsky equations for the α particle. The ghost states calculated by rigorous and approximate methods turn out to have a very similar form. It is analytically proved that the trace of the norm kernel does not depend on the inner wave function we choose
Discrepancy in the cross section minimum of elastic nucleon-deuteron scattering
Δ-isobar excitation in the nuclear medium yields an effective three-nucleon force. A coupled-channel formulation of nucleon-deuteron scattering with Δ-isobar excitation developed previously is used. The three-particle scattering equations are solved by a separable expansion of the two-baryon transition matrix below the inelastic threshold of pion production. The effect of Δ-isobar excitation on the spin-averaged differential cross section is studied. The discrepancy between theory and experiment in the diffraction minimum is reduced
Variational Calculations of the Nucleus Structure in a 3 Model Using a Deep Potential with Forbidden States
The energy spectrum of the nucleus with and
is investigated in the framework of the multicluster dynamical model
by using a deep -potential with forbidden states in the S and D
waves. A very high sensitivity of the compact ground and first excited
states energy levels to the description of the two-body forbidden states wave
functions has been estabilished. It is shown also that the chosen method of
orthogonalizing pseudopotentials yields convergent results for the energies of
the excited and states of the nucleus with a
well developed cluster like structure