CP Violation in Flavor Tagged $$B_s \to J/\psi \phi$$ Decays

Thesis/Dissertation · Mon Jun 01 00:00:00 EDT 2009

DOI:https://doi.org/10.2172/981875· OSTI ID:981875

Makhoul, Khaldoun ^[1]

---

1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

In this dissertation, we present the results of a time-dependent angular analysis of B_s → J/ΨΦ decays performed with the use of initial-state flavor tagging. CP violation is observed in this mode through the interference of decay without net mixing and decay with net mixing, that is, B_s → J/ΨΦ and B_s → $$\bar{B}$$_s → J/ΨΦ . The time-dependent angular analysis is used to extract the decay widths of the heavy and light B_s eigenstates and the difference between these decay widths ΔΓ_s {triple_bond} Γ_s^L-Γ_s^H. Initial-state flavor tagging is used to determine the matter-antimatter content of the B_s mesons at production time. We combine flavor tagging with the angular analysis, which statistically determines the contributions of the CP-even and CP-odd components at decay time, to measure the CP-violating phase β_s. The phase β_s is expressed in terms of elements of the Cabibbo-Kobayashi-Maskawa matrix as β_s {triple_bond} arg (-V_tsV*_tb/V_csV*_cb), and is predicted by the Standard Model to be close to zero, β_s^SM = 0.02. In the measurement of ΔΓ_s, we use a dataset corresponding to 1.7 fb^-1 of luminosity, collected at the CDF experiment from proton-antiproton collisions at a center of mass energy √s = 1.96 TeV. In the measurement of β_s, we use a dataset corresponding to 1.3 fb^-1 of collected luminosity. We measure ΔΓ_s = (0.071_-0.059^+0.064 ± 0.007) ps^-1 using the time-dependent angular analysis. Combining the angular analysis with flavor-tagging, we find that assuming the Standard Model predictions of β_s and ΔΓ_s, the probability of a deviation as large as the level of the observed data is 33%. We obtain a suite of associated results which are discussed in detail in this dissertation alongside the main results.

• Research Organization: Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 981875
• Report Number(s): FERMILAB-THESIS-2009-60; TRN: US1004112
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
A CENTERS
DECAY
EIGENSTATES
FERMILAB COLLIDER DETECTOR
LUMINOSITY
MESONS
PROBABILITY
PRODUCTION
STANDARD MODEL
Experiment-HEP