s-Wave Approximation for Asymmetry in Nonmesonic Decay of Finite Hypernuclei

We establish the bridge between the commonly used Nabetani-Ogaito-Sato-Kishimoto (NOSK) formula for the asymmetry parameter $a_\Lambda$ in the $\vec\Lambda p \to np$ emission of polarized hypernuclei, and the shell model (SM) formalism for finite hypernuclei. We demonstrate that the s-wave approximation leads to a SM formula for $a_\Lambda$ that is as simple as the NOSK one, and that reproduces the exact results for $^5_\Lambda$He and $^{12}_\Lambda$C better than initially expected. The simplicity achieved here is indeed remarkable. The new formalism makes the theoretical evaluation of $a_\Lambda$ more transparent, and explains clearly why the one-meson exchange model is unable to account for the experimental data of $^5_\Lambda$He.Comment: 9 pages. to be published in Physical Review

Weak meson vertices and the hypernuclear potential

This paper is a continuation of an earlier paper on hypernuclear potentials. A novel derivation of the hypernuclear strangeness-violating potential due to the pseudoscalar meson exchanges is presented. Comparison with the earlier method shows that the theoretical uncertainty is less than 30%. Relative signs of pseudoscalar meson exchanges and vector (axial vector) exchanges are discussed in detail. Additional comments on the nonrelativistic approximation are included

Hypernuclear potentials and the pseudoscalar meson exchange contribution

The pieces of the hypernuclear strangeness violating potential due to the pseudoscalar meson exchanges are derived using methods which were successfully applied to hyperon nonleptonic decays. The estimates are tested by comparison with measured hyperon nonleptonic decay amplitudes. All isospin changes $\Delta I=1/2$ and $\Delta I=3/2$ are included in the derived potential. All calculational methods used are reviewed and described in detail

Hypernuclear potentials and the pseudoscalar meson exchange contribution

The pieces of the hypernuclear strangeness violating potential due to the pseudoscalar meson exchanges are derived using methods which were successfully applied to hyperon nonleptonic decays. The estimates are tested by comparison with measured hyperon nonleptonic decay amplitudes. All isospin changes ∆I = 1/2 and ∆I = 3/2 are included in the derived potential. All computational methods used are reviewed and described in detail

Slabi mezonski vrhovi i hipernukleonski potencijal

This paper is a continuation of an earlier paper on hypernuclear potentials. A novel derivation of the hypernuclear strangeness-violating potential due to the pseudoscalar meson exchanges is presented. Comparison with the earlier method shows that the theoretical uncertainty is less than 30%. Relative signs of pseudoscalar meson exchanges and vector (axial vector) exchanges are discussed in detail. Additional comments on the nonrelativistic approximation are included.Ovaj je članak nastavak ranijeg članka o hipernuklearnim potencijalima. Predstavljamo nov izvod hipernuklearnog potencijala koji krši stranost a posljedica je izmjene pseudoskalarnih mezona. Usporedba s ranijom metodom pokazuje da je teorijska netočnost manja od 30%. Raspravljaju se podrobno relativni predznaci izmjena pseudoskalarnih mezona i vektorskih (aksijalno vektorskih) izmjena. Daju se dodatne napomene o nerelativističkom približenju

Hipernuklearni potencijali i doprinos izmjene pseudoskalarnih mezona

The pieces of the hypernuclear strangeness violating potential due to the pseudoscalar meson exchanges are derived using methods which were successfully applied to hyperon nonleptonic decays. The estimates are tested by comparison with measured hyperon nonleptonic decay amplitudes. All isospin changes ∆I = 1/2 and ∆I = 3/2 are included in the derived potential. All computational methods used are reviewed and described in detail.Izvodimo dijelove hipernuklearnog potencijala koji krši stranost zbog izmjene pseudoskalarnih mezona primjenom metoda koje su uspješno primijenjene za hiperonske neleptonske raspade. Ocjene se provjeravaju usporedbom s mjerenim amplitudama neleptonskih raspada hiperona. Sve su promjene izospina, ∆I = 1/2 i ∆I = 3/2, uključene u izvedeni potencijal. Podrobno opisujemo sve računalne metode