Observation of Direct CP Violation in $$K_{S,L} \to \pi \pi$$ Decays

Thesis/Dissertation · Wed Dec 01 04:00:00 EST 1999

DOI:https://doi.org/10.2172/1421515· OSTI ID:1421515

Shawhan, Peter Sven ^[1]

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1. Chicago U., Astron. Astrophys. Ctr.

This thesis concerns the fundamental symmetry properties of elementary particle interactions. Specifically, it is an experimental investigation of the slight violation of CP symmetry (the combination of charge conjugation and parity inversion) by the weak force. We have used data from the KTeV experiment, located at the Fermi National Accelerator Laboratory (Fermilab), to compare the decay rates of the short- and long-lived neutral K mesons ($$K_S$$ and $$K_L$$) to $$\pi^+\pi^-$$ and $$\pi^0\pi^0$$ final states. From this comparison, we find that the \direct" CP-violation parameter Re($$\epsilon^{\prime}$$/$$\epsilon$$) is equal to (28.0 $$\pm$$ 3.0 $$\pm$$ 2.8)$$\pm$$ $$10^{-4}$$, where the first error is statistical and the second is systematic. This nonzero result definitively establishes the existence of CP violation in a decay process

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1421515
• Report Number(s): FERMILAB-THESIS-1999-21; UMI-99-51837; 508460
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS