Rare Nonleptonic Decays of the Omega Hyperon: Measurements of the Branching Ratios for Ω∓ --> Ξ$$*0\atop{(1530)}$$ (anti-Ξ$$*0\atop{(1530)}$$) π∓ and Ω∓→ Ξ∓ π± π∓
- Illinois Inst. of Technology, Chicago, IL (United States)
A clean signal of 78 (24) events has been observed in the rare nonleptonic particle (antiparticle) decay modes Ω∓ → Ξ∓π±π∓ using data collected with the HyperCP spectrometer during Fermilab's 1999 fixed-target run. We obtain B(Ω- → Ξ-π+π-) = [4.32 ± 0.56(stat) ± 0.28(syst)] x 10-4 and B(Ω+ → Ξ+π-π+) = 3.13 ± 0.71(stat) ± 0.20(syst) x 10-4. This is the first observation of the antiparticle mode. Our measurement for the particle mode agrees with the previous experimental result and has an order-of-magnitude better precision. We extract the contribution from the resonance decay mode Ω∓ → Ξ$$*0\atop{(1530)}$$ (Ξ$$*0\atop{(1530)}$$)π∓ to the final state Ξ∓π±π∓. This the first actual measurement of the resonance-mode branching ratios, gives B(Ω- → Ξ$$*0\atop{(1530)}$$ π-) = [4.55 ± 2.33(stat) ± 0.38(syst)] x 10-5, B(Ω+ → Ξ$$*0\atop{(1530)}$$π+) = [1.40 ± 2.83(stat) ± 0.12(syst)] x 10-5 and disagrees with the current Particle Data Group review value, being ~ 14 times smaller. Since the central value of the resonance-mode branching ratio is less than two standard deviations away from zero, we also calculate branching ratio upper limits at 90% confidence level: B(Ω- → Ξ$$*0\atop{(1530)}$$ π-) < 7.61 x 10-5 and B(Ω+ → Ξ$$*0\atop{(1530)}$$ π+) < 5.61 x 10-5. This analysis provides new data on nonleptonic hyperon decays which allows studies of how weak interaction processes occur in the presence of strong interactions.
- Research Organization:
- Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC02-07CH11359
- OSTI ID:
- 921108
- Report Number(s):
- FERMILAB-THESIS-2007-40; TRN: US0801932
- Country of Publication:
- United States
- Language:
- English
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