Nonmesonic weak decay spectra of $^{4}_\Lambda$He

E. BAUER,A. P. GALEÃO, M, HUSSEIN, F. KRMPOTIC,J.D.PARKER

PHYSICS LETTERS B

ELSEVIER SCIENCE BV

Año: 2009 vol. 674 p. 103 - 110

0370-2693

To comprehend the recent Brookhaven National Laboratory experiment E788 on  $^4_Lambda$He, we have outlined  a simple theoretical framework for the one-nucleon induced nonmesonic weak decay spectra.Basically, the shapes of all the spectra are tailored by the kinematics ofthe corresponding phase space, depending veryweakly on the dynamics which is gauged here by the one-meson-exchange-potencial.In spite of the straightforwardness of the approach the agreement with data isexceptionally  good. This might indicate  that  the final-state-interactionsand the two-nucleon induced decay processes are not very important  in this decay.We have also found that the $pi+K$ exchange potentialwith soft cutoffs $(Lambda_picong 0.7$ GeV,$Lambda_Kcong 0.9$ GeV), is capable to account for the experimental values of $Gamma_p$ and $Gamma_n$for  $^4_Lambda$H, $^4_Lambda$He, and $^5_Lambda$He.