Neutron and proton energy spectra from the non-mesonic weak decays of 5_Lambda-He and 12_Lambda-C

Abstract

We have simultaneously measured the energy spectra of neutrons and protons emitted in the non-mesonic weak decays of 5_Lambda-He and 12_Lambda-C hypernuclei produced via the (pi^+,k^+) reaction with much higher statistics over those of previous experiments. The neutron-to-proton yield ratios for both hypernuclei at a high energy threshold (60 MeV) were approximately equal to two, which suggests that the ratio of the neutron- and proton-induced decay channels, Gn(Lambda n -> nn)/Gp(Lambda p -> np), is about 0.5. In the neutron energy spectra, we found that the yield of the low-energy component is unexpectedly large, even for 5_Lambda-He.

13pages, 4figures, submitted to Physics Letters B

References in corpus (8)

• The Weak Decay of Hypernuclei
• Weak Decay of Lambda Hypernuclei
• Theory of Weak Hypernuclear Decay
• Final State Interactions in Hypernuclear Decay
• Weak Decay of $\Lambda$ in Nuclei : Quarks vs Mesons
• Towards the solution of the Gn/Gp Puzzle in the Non-Mesonic Weak Decay of Lambda-Hypernuclei
• Non-mesonic Weak Decays of Light Hypernuclei in the Direct Quark and the One-Pion Exchange Mechanisms
• Direct quark transition potential for $\Lambda N\to NN$ decay

Cited by in corpus (26)

• Strangeness in nuclear physics
• Strangeness nuclear physics: a critical review on selected topics
• Coincidence Measurement of the Nonmesonic Weak Decay of ^{12}_{Lambda}C
• Exclusive Measurement of the Nonmesonic Weak Decay of ^{5}_ΛHe Hypernucleus
• Measurement of the proton spectra from Non-Mesonic Weak Decay of ${}_{\Lambda }^{5}He$, ${}_{\Lambda }^{7}Li$ and ${}_{\Lambda }^{12}C$
• Two-pion-exchange in the non-mesonic weak decay of $\Lambda$-hypernuclei
• Single and double coincidence nucleon spectra in the weak decay of Lambda hypernuclei
• Asymmetries in the Non-Mesonic Weak Decay of Polarized Lambda-Hypernuclei
• Nonmesonic Weak Decay of $\Lambda$ Hypernuclei within a Nuclear Matter Formalism
• pi^0 decay branching ratios of 5_Lambda-He and 12_Lambda-C hypernuclei
• Precise determination of ${}_{\Lambda }^{12}$C level structure by $\gamma$-ray spectroscopy
• First determination of the one-proton induced Non-Mesonic Weak Decay width of p-shell Λ-Hypernuclei
• Microscopic Approach to Nucleon Spectra in Hypernuclear Non-Mesonic Weak Decay
• Quantum interference terms in nonmesonic weak decay of $\Lambda$-hypernuclei within a RPA formalism
• Nonmesonic weak decay of $\Lambda$ hypernuclei within a nuclear matter framework
• Kinetic energy sum spectra in nonmesonic weak decay of hypernuclei
• Relationships between nonmesonic-weak-decays in different hypernuclei
• Nonmesonic weak decay spectra of ${}_{\Lambda }^4$He
• Non-Mesonic Weak Decay of Lambda-hypernuclei: a new determination of the Gn/Gp ratio
• On the effect of the Delta(1232) in hypernuclear non-mesonic weak decay: a microscopic approach
• Nucleon-nucleon coincidence measurement in the non-mesonic weak decay of 5_Lambda-He and 12_Lambda-C hypernuclei
• Nonmesonic weak decay spectra of light hypernuclei
• Nonmesonic Weak Decay Dynamics from proton spectra of $\Lambda$-Hypernuclei
• A Theoretical Determination of N_{nn}/N_{np} in Hypernuclear Non--Mesonic Weak Decay
• Effects of $\Lambda \Lambda -\Xi N$ mixing in the decay of $S=-2$ hypernuclei
• Exchange Reactions with Dick Dalitz