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Our earlier Faddeev three-body study in the $K^-$-deuteron scattering length, $A_{K^-d}$, is revisited here in the light of the recent developments in two fronts: {it (i)} the improved chiral unitary approach to the theoretical description of the cou pled $Kbar N$ related channels at low energies, and {it (ii)} the new and improved measurement from SIDDHARTA Collaboration of the strong interaction energy shift and width in the lowest $K^-$-hydrogen atomic level. Those two, in combination, have allowed us to produced a reliable two-body input to the three-body calculation. All available low-energy $K^-p$ observables are well reproduced and predictions for the $Kbar N$ scattering lengths and amplitudes, $(pi Sigma)^circ$ invariant-mass spectra, as well as for $A_{K^-d}$ are put forward and compared with results from other sources. The findings of the present work are expected to be useful in interpreting the forthcoming data from CLAS, HADES, LEPS and SIDDHARTA Collaborations.
We study the production of $Xi^-$-hypernuclei, $^{12}_{Xi^{-}}$Be and $^{28}_{Xi^{-}}$Mg, via the ($K^-,K^+$) reaction within a covariant effective Lagrangian model, employing the bound $Xi^-$ and proton spinors calculated by the latest quark-meson c oupling model. The present treatment yields the $0^circ$ differential cross sections for the formation of simple s-state $Xi^-$ particle-hole states peak at a beam momentum around 1.0 GeV/c with a value in excess of 1 $mu$b.
180 - K. Tsushima , A. W. Thomas 2012
We study the effect of a $Lambda$ hyperon immersed in the doubly magic nuclei, $^{16}$O, $^{40}$Ca, $^{48}$Ca, and $^{208}$Pb, as well as the neutron magic nucleus $^{90}$Zr. For a $Lambda$ in the $1s$ and $1p$ states in $^{17}_{Lambda}$O, $^{41}_{La mbda}$Ca, $^{49}_{Lambda}$Ca, $^{91}_{Lambda}$Zr, and $^{209}_{Lambda}$Pb, we compare the single-particle energies and density distributions of the core nucleons with those of the nuclei without the $Lambda$, as well as the point proton and neutron radii. A remarkable finding is that the bound $Lambda$ induces a significant asymmetry in the proton-neutron density distributions in the core nucleus. This in turn gives rise to an appreciable, iso-vector mean field. As a consequence, the neutrons in the core are more attracted to the center of the nucleus, while the protons are pushed away, in comparison with those in the corresponding nucleus without the $Lambda$.
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