Weak Decay of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">C</mml:mi></mml:mrow><mml:mprescripts/><mml:mrow><mml:mi>Λ</mml:mi></mml:mrow><mml:mrow><mml:mn>12</mml:mn></mml:mrow><mml:mrow/><mml:mrow/></mml:mmultiscripts></mml:mrow></mml:math>and<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:mmultiscripts><mml:mrow><mml:mi mathvariant="normal">B</mml:mi></mml:mrow><mml:mpr

We take an approach to the Λ non-mesonic weak decay in nuclei based on the exchange of mesons. The one pion and one kaon exchange are considered, together with the exchange of two pions, either correlated, leading to an important scalar-isoscalar exchange (σ-like exchange), or uncorrelated (box diagrams). Extra effects of omega exchange in the scalar-isoscalar channel are also considered. Constraints of chiral dynamics are used to generate these exchanges. A drastic reduction of the OPE results for the Γ n /Γ p ratio is obtained and the new results are compatible with all present experiments within errors. The absolute rates obtained for different nuclei are also in good agreement with experiment.[Key Word] Λ weak decay, Γ n /Γ p ratio, chiral unitary theory.

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“…Λ B 1.37 ± 0.17 [6,47] (K − , π − ) 1.25 ± 0.08 [48] (π + , K + ) 12 Λ C 1.25 ± 0.19 [6,47] (K − , π − ) 1.14 ± 0.08 [49] (π + , K + ) …”

Section: Resultsunclassified

Meson exchange in the weak decay of Λ hypernuclei and the Γn/Γp ratio

2001

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“…(26) and (27), leading to a local function, and providing further insight in the meaning of the LDA approximation in inclusive processes.…”

Section: Equivalence Of the Propagator And Wave Function Methodsmentioning

confidence: 96%

Weak decay of Λ hypernuclei

Oset

1998

Progress in Particle and Nuclear Physics

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We review recent developments concerning the weak decay of Λ hypernuclei. New studies covering the mesonic decay channel as well as recent models for the non-mesonic one are discussed and compared with experimental data. The puzzle of the neutron-to proton-induced decay ratio, Γ n /Γ p , is addressed in connection to the two-nucleon induced decay channel and proposals for more efficient experimental analyses of this ratio are made. : 21.80.+a, 13.30.Eg, 25.80.Pw, 13.75.Ev Keywords: Λ hypernuclei, Mesonic decay of hypernuclei, Non-mesonic decay of hypernuclei, Weak interaction, ∆I = 1/2 rule. PACS

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“…However, the pion can excite ph components in the medium leading to a new Λ(1115) decay mode Λ(1115) → N ph, or equivalently Λ(1115)N → N N , non mesonic decay. This new decay channel is far bigger than the mesonic decay in the nucleus and as large as the free one [25,26,27,28,29,30].…”

Section: Introductionmentioning

confidence: 92%

Λ(1520)andΣ(1385)in the nuclear medium

Kaskulov

Oset

2006

Phys. Rev. C

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Recent studies of the Λ(1520) resonance within chiral unitary theory with coupled channels find the resonance as a dynamically generated state from the interaction of the decuplet of baryons and the octet of mesons, essentially a quasibound state of πΣ * (1385) in this case, although the coupling of the Λ(1520) to theKN and πΣ makes this picture only approximate. The πΣ * (1385) decay channel of the Λ(1520) is forbidden in free space for the nominal mass of the Σ * (1385), but the coupling of the π to ph components in the nuclear medium opens new decay channels of the Λ(1520) in the nucleus and produces a much larger width. Together with medium modifications of theKN and πΣ decay channels, the final width of the Λ(1520) at nuclear matter density is more than five times bigger than the free one. We perform the calculations by dressing simultaneously the Λ(1520) and the Σ * (1385) resonances, finding moderate changes in the mass but substantial ones in the width of both resonances.

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Weak Decay ofCΛ12andB

Cited by 105 publications

References 13 publications

Meson exchange in the weak decay of Λ hypernuclei and the Γn/Γp ratio

Meson exchange in the weak decay of Λ hypernuclei and the Γn/Γp ratio

Weak decay of Λ hypernuclei

Λ(1520)andΣ(1385)in the nuclear medium

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