Measurement of Angle beta with Time-dependent CPAsymmetry in B0 to K+K-K0 Decays
In the Standard Model (SM) of particle physics, the phase of the Cabibbo-Kobayashi-Maskawa (CKM) quark-mixing matrix [1, 2] is the only source of CP violation in the quark sector. Due to the interference between mixing and decay, this phase can be observed in measurements of time-dependent CP asymmetries of B{sup 0} mesons. In the SM, CP asymmetries in b {yields} s{bar s}s decays, such as B{sup 0} {yields} K{sup +}K{sup -}K{sup 0}, are expected to be nearly equal to those observed in tree-dominated b {yields} {bar c}s decays [3]. However, because in the SM the former are dominated by loop amplitudes, new particles in those loops potentially introduce new physics at the same order as the SM process. Within the SM, deviations from the expected CP asymmetries in B{sup 0} {yields} K{sup +}K{sup -}K{sup 0} decays depend on the Dalitz plot position, but are expected to be small and positive [4]. In particular, for the decay B{sup 0} {yields} {phi}K{sup 0} they are expected to be less than 4%. BABAR extracts the time-dependent CP-violation parameters by taking into account different amplitudes and phases across the B{sup 0} and {bar B}{sup 0} Dalitz plots, while Belle measures it separately for B{sup 0} {yields} {phi}K{sup 0} and the rest of K{sup +}K{sup -}K{sup 0} events, neglecting interference between intermediate states. The analyses presented here are based on 347 (535) million B{bar B} pairs collected with the BABAR (Belle) detector at the SLAC PEP-II (KEKB) e{sup +}e{sup -} asymmetric-energy collider. Data are collected on the {Upsilon}(4S) resonance, while a fraction of about 10% is collected at approximately 40 MeV below the {Upsilon}(4S) resonance, and it is used to study the background arising from e{sup +}e{sup -} {yields} q{bar q} (q = u, d, s, c) continuum events. The BABAR and Belle detectors are described in detail elsewhere [5].
- Research Organization:
- SLAC National Accelerator Lab., Menlo Park, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC02-76SF00515
- OSTI ID:
- 899558
- Report Number(s):
- SLAC-PUB-12323; hep-ex/0701047; TRN: US200709%%174
- Resource Relation:
- Conference: Invited talk at 4th International Workshop on the CKM Unitarity Triangle (CKM 2006), Nagoya, Japan, 12-16 Dec 2006
- Country of Publication:
- United States
- Language:
- English
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