- th / 9 90 20 23 v 1 9 F eb 1 99 9 Weak decays of medium and heavy Λ - hypernuclei
نویسندگان
چکیده
We have made a new evaluation of the Λ decay width in nuclear matter within the Propagator Method. Through the Local Density Approximation it is possible to obtain results in finite nuclei. We have also studied the dependence of the widths on the N N and ΛN short range correlations. Using reasonable values for the parameters that control these correlations, as well as realistic nuclear densities and Λ wave functions, we reproduce, for the first time, the experimental non-mesonic widths in a wide range of mass numbers (from medium to heavy hypernuclei).
منابع مشابه
ar X iv : n uc l - th / 9 71 10 49 v 2 5 J an 1 99 9 π + Emission from Hypernuclei and the Weak ∆ I = 3 / 2 Transitions
Low energy π emission in hypernuclear weak decays is studied in the soft pion limit. It is found that the π decay amplitude is dominated by the ∆I = 3/2 part of nonmesonic weak decays according to the soft pion theorem. The ratios, R(π/soft π−), for light hypernuclei are estimated in the direct quark mechanism, which predicts violation of the ∆I = 1/2 rule, and found to be about 1/3 for 4ΛHe. ∗...
متن کاملar X iv : n uc l - th / 9 90 20 34 v 1 1 5 Fe b 19 99 Submitted to Physical Review C FSU - SCRI - 99 - 07 Relativistic Treatment of Hypernuclear Decay
We compute for the first time the decay width of Λ-hypernuclei in a rela-tivistic mean-field approximation to the Walecka model. Due to the small mass difference between the Λ-hyperon and its decay products—a nucleon and a pion—the mesonic component of the decay is strongly Pauli blocked in the nuclear medium. Thus, the in-medium decay becomes dominated by the non-mesonic, or two-body, componen...
متن کاملar X iv : n uc l - th / 9 71 10 54 v 1 2 6 N ov 1 99 7 The π + – emission puzzle in 4 Λ He decay
We re-examine the puzzling π emission from the weak decay of 4ΛHe and propose an explanation in terms of a three–body decay of the virtual Σ. Such a resolution of the π decay puzzle is consistent with the calculated Σ probability in light Λ hypernuclei as well as the experimentally observed π energy spectrum and s–wave angular distribution. Typeset using REVTEX
متن کاملar X iv : n uc l - th / 9 71 10 49 v 1 2 5 N ov 1 99 7 π + Emission from Hypernuclei and the Weak ∆
Low energy π emission in hypernuclear weak decays is related to ∆I = 3/2 part of nonmesonic weak decays according to the soft pion theorem. We show that neither meson exchange pictures nor virtual Σ excitation can solve the π emission puzzle. On the other hand, the direct quark mechanism gives the ratio R(π/π : S-wave, soft pion) ≈ 1/4 for 4ΛHe and 5ΛHe. ∗email: [email protected]
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