Study of CP Violation in Dalitz-Plot Analyses of B-Meson Decays to Three Kaons

Thesis/Dissertation · Wed Feb 01 00:00:00 EST 2012

DOI:https://doi.org/10.2172/1035074· OSTI ID:1035074

Lindquist, Brian ^[1]

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1. Stanford Univ., CA (United States)

The Standard Model (SM) explains CP violation in terms of the CKM matrix. The BABAR experiment was designed mainly to test the CKM model in B decays. B decays that proceed through b → s loop diagrams, of which B {yields} KKK decays are an example, are sensitive to new physics effects that could lead to deviations from the CKM predictions for CP violation. We present studies of CP violation in the decays B⁺ → K⁺K^-K⁺, B⁺ → K_S⁰K_S⁰K⁺, and B⁰ → K⁺K^-K_S⁰, using a Dalitz plot amplitude analysis. These studies are based on approximately 470 million B$$\bar{B}$$ decays collected by BABAR at the PEP-II collider at SLAC. We perform measurements of time-dependent CP violation in B⁰ → K⁺K^-K_S⁰, including B⁰ → ΦK_S⁰. We measure a CP-violating phase β_eff (ΦK_S⁰) = 0.36 ± 0.11 ± 0.04 rad., in agreement with the SM. This is the world's most precise measurement of this quantity. We also measure direct CP asymmetries in all three decay modes, including the direct CP asymmetry A_CP (ΦK⁺) = (12.8 ± 4.4 ± 1.3)%, which is 2.8 sigma away from zero. This measurement is in tension with the SM, which predicts an asymmetry of a few percent. We also study the resonant and nonresonant features in the B → KKK Dalitz plots. We find that the hypothetical scalar f_X(1500) resonance, introduced by prior analyses to explain an unknown peak in the m_KK spectrum, cannot adequately describe the data. We conclude instead that the f_X(1500) can be explained as the sum of the f₀(1500), f'₂(1525), and f₀(1710) resonances, removing the need for the hypothetical f_X(1500). We also find that an exponential nonresonant model, used by previous analyses to describe the broad nonresonant feature seen in B → KKK decays, cannot fully model the data. We introduce a new nonresonant model that contains more free parameters, allows for phase motion, and contains both S-wave and P-wave components.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 1035074
• Report Number(s): SLAC-R-984; TRN: US1201025
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
AMPLITUDES
ASYMMETRY
CP INVARIANCE
DALITZ PLOT
DECAY
KAONS
PHYSICS
RESONANCE
SCALARS
STANDARD MODEL
STANFORD LINEAR ACCELERATOR CENTER
Experiment-HEP
HEPEX