Mesonic and nonmesonic weak decay widths of medium-heavy {lambda} hypernuclei
- Department of Physics, Tohoku University, Sendai 980-8578 (Japan)
- Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan)
- High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801 (Japan)
- Department of Physics, Seoul National University, Seoul 151-742, Korea (Korea, Republic of)
- Graduate School of Science, University of Tokyo, Tokyo 113-0033 (Japan)
- Department of Physics, Seoul National University, Seoul 151-742 (Korea, Republic of)
We have measured the energy spectra of pions and protons emitted in the weak decay of {sup {lambda}}{sub 12}C, {sup {lambda}}{sub 28}Si, and hypernuclei produced via the ({pi}{sup +},K{sup +}) reaction. The decay widths of the {pi}{sup -} mesonic decay ({lambda}{yields}p{pi}{sup -}) and the nonmesonic decay ({lambda}N{yields}NN) were extracted. The present results demonstrate an increase of the mesonic decay width due to a distortion of the pion wave function in nuclear medium for the first time. The ratios of the neutron- to proton-induced nonmesonic decay widths, {gamma}{sub n}({lambda}n{yields}nn)/{gamma}{sub p}({lambda}p{yields}np), were evaluated by a direct comparison of the measured proton energy spectra with the calculated ones. No theoretical calculation which has been proposed so far can simultaneously account for both the nonmesonic decay widths and the {gamma}{sub n}/{gamma}{sub p} ratios in the present data.
- OSTI ID:
- 20695960
- Journal Information:
- Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 2 Vol. 71; ISSN 0556-2813; ISSN PRVCAN
- Country of Publication:
- United States
- Language:
- English
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