5,158 research outputs found
Linear correlations between 4He trimer and tetramer energies calculated with various realistic 4He potentials
In a previous work [Phys. Rev. A 85, 022502 (2012)] we calculated, with the
use of our Gaussian expansion method for few-body systems, the energy levels
and spatial structure of the 4He trimer and tetramer ground and excited states
using the LM2M2 potential, which has a very strong short-range repulsion. In
this work, we calculate the same quantities using the presently most accurate
4He-4He potential [M. Przybytek et al., Phys. Rev. Lett. 104, 183003 (2010)]
that includes the adiabatic, relativistic, QED and residual retardation
corrections. Contributions of the corrections to the tetramer
ground-(excited-)state energy, -573.90 (-132.70) mK, are found to be,
respectively, -4.13 (-1.52) mK, +9.37 (+3.48) mK, -1.20 (-0.46) mK and +0.16
(+0.07) mK. Further including other realistic 4He potentials, we calculated the
binding energies of the trimer and tetramer ground and excited states, B_3^(0),
B_3^(1), B_4^(0) and B_4^(1), respectively. We found that the four kinds of the
energies for the different potentials exhibit perfect linear correlations
between any two of them over the range of binding energies relevant for 4He
atoms (namely, six types of the generalized Tjon lines are given). The
dimerlike-pair model for 4He clusters, proposed in the previous work, predicts
a simple universal relation B_4^(1)/B_2 =B_3^(0)/B_2 + 2/3, which precisely
explains the correlation between the tetramer excited-state energy and the
trimer ground-state energy, with B_2 being the dimer binding energy.Comment: 10 pages, 3 figures, published version in Phys. Rev. A85, 062505
(2012), Figs. 2, 5, and 6 added, minor changes in the description of the
dimerlike-pair mode
Constituent quark model for baryons with strong quark-pair correlations and non-leptonic weak transitions of hyperon
We study the roles of quark-pair correlations for baryon properties, in
particular on non-leptonic weak decay of hyperons. We construct the quark wave
function of baryons by solving the three body problem explicitly with
confinement force and the short range attraction for a pair of quarks with
their total spin being 0. We show that the existence of the strong quark-quark
correlations enhances the non-leptonic transition amplitudes which is
consistent with the data, while the baryon masses and radii are kept to the
experiment.Comment: 4 pages, 2 figures, talk presented at KEK-Tanashi International
Symposium on Physics of Hadrons and Nuclei, Tokyo, Japan, 14-17 Dec. 199
Modelling double charge exchange response function for tetraneutron system
This work is an attempt to model the response function of a recent RIKEN
experimental study of the double charge exchange He(He,Be)n
reaction in order to put in evidence an eventual enhancement mechanism of the
zero energy cross section, including a near-threshold resonance. This resonance
can indeed be reproduced only by adding to the standard nuclear Hamiltonian an
unphysically large T=3/2 attractive 3n-force which destroys the neighboring
nuclear chart. No other mechanisms like cusps or related structures were found
Four- and Five-Body Scattering Calculations
We study the five-quark system in the standard
non-relativistic quark model by solving the scattering problem. Using the
Gaussian Expansion Method (GEM), we perform the almost precise multi-quark
calculations by treating a very large five-body modelspace including the NK
scattering channel explicitly. Although a lot of pseudostates (discretized
continuum states) with and are obtained
within the bound-state approximation, all the states in GeV in mass
around melt into non-resonant continuum states
through the coupling with the NK scattering state in the realistic case, i.e.,
there is no five-quark resonance below 1.85GeV. Instead, we predict a
five-quark resonance state of with the mass of about 1.9GeV and
the width of 2.68MeV. Similar calculation is done for the
four-quark system () in connection with
X(3872)
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