AN HISTORICAL OVERVIEW OF THE IMPORTANCE OF THE WEAK DECAY OF HYPERNUCLEI
Weak decay of hypernuclei, first cousin to the {beta}-decay of conventional, nonstrange nuclei, was initially observed in the 1950s. Pionic decay rates have proven a challenge--to reconcile nuclear decay rates with that of free {lambda} decay. Pauli blocking of the decay nucleon plays an important role. Nonmesonic decay provides our only practical means of exploring the four-fermion, strangeness-changing N{Lambda} {yields} NN weak interaction. The N{Lambda}{rho} vertex can be investigated in no other way. The large momentum transfer in the nonmesonic decay process suggests a means to probe short distance aspects of the interaction, possibly revealing baryon substructure effects. Whether the {Delta}I = 1/2 rule, which governs free {Lambda} decay, also applies to the nonmesonic decay process remains an open question. The free {Lambda} does not decay by emission of a {pi}{sup +}; the {pi}{sup +} decay of {sup 4}He is a puzzle. Finally, the weak decay of strangeness -2 hypernuclei is an important topic, because the pionic decay process is central to current efforts to seek and identify {Lambda}{Lambda} hypernuclei.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 772925
- Report Number(s):
- LA-UR-01-20; TRN: US0602442
- Resource Relation:
- Journal Volume: 691; Journal Issue: 1-2; Conference: Intl' Conf. on Hypernuclear and Strange Particle Physics, Torino, Italy, Oct. 23-27,2000
- Country of Publication:
- United States
- Language:
- English
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