1,678 research outputs found
A microscopic NN to NN*(1440) potential
By means of a NN to NN*(1440) transition potential derived in a
parameter-free way from a quark-model based NN potential, we determine
simultaneously the and coupling constants.
We also present a study of the target Roper excitation diagram contributing to
the reaction.Comment: Talk presented at the Fourth International Conference on Perspectives
in Hadronic Physics (ICTP, Trieste, Italy, May 2003). To appear in EPJA. 6
pages, 9 figures, needs svepj.clo and svjour.cl
A Consistent Study of the the Low Energy Baryon Spectrum and the Nucleon-Nucleon Interaction within the Chiral Quark Model
By solving the Schr\"{o}dinger equation for the three-quark system in the
hyperspherical harmonic approach, we have studied the low energy part of the
nucleon and spectra using a quark-quark interaction which reproduces
the nucleon-nucleon phenomenology. The quark-quark hamiltonian considered
includes, besides the usual one-gluon exchange, pion and sigma exchanges
generated by the chiral symmetry breaking. The baryonic spectrum obtained is
reasonable and the resulting wave function gives consistency to the ansatz used
in the two baryon system.Comment: Accepted for publication in Phys. Lett.
Effect of higher orbital angular momenta in the baryon spectrum
We have performed a Faddeev calculation of the baryon spectrum for the chiral
constituent quark model including higher orbital angular momentum states. We
have found that the effect of these states is important, although a description
of the baryon spectrum of the same quality as the one given by including only
the lowest-order configurations can be obtained. We have studied the effect of
the pseudoscalar quark-quark interaction on the relative position of the
positive- and negative-parity excitations of the nucleon as well as the effect
of varying the strength of the color-magnetic interaction.Comment: 7 pages, 4 figures. To be published in Phys. Rev. C (November 2001
scattering lengths from a quark-model based interaction
We calculate the doublet and quartet neutron-deuteron scattering lengths
using a nonlocal nucleon-nucleon interaction fully derived from quark-quark
interactions. We use as input the and - partial
waves. Our result for the quartet scattering length agrees well with the
experimental value while the result for the doublet scattering length does not.
However, if we take the result for the doublet scattering length together with
the one for the triton binding energy they agree well with the so-called
Phillips line.Comment: 6 pages, 2 tables. Accepted for publication in Physical Review
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