Precise Measurements of Direct CP Violation, CPT Symmetry, and Other Parameters in the Neutral Kaon System
Journal
Physical Review
Journal Volume
D83
Pages
092001
Date Issued
2010-11
Author(s)
Abouzaid, E.
Abstract
We present precise tests of CP and CPT symmetry based on the full data set of K→ππ decays collected by the KTeV experiment at Fermi National Accelerator Laboratory during 1996, 1997, and 1999. This data set contains 16×106 K→π0π0 and 69×106 K→π+π - decays. We measure the direct CP violation parameter Re(ε′/ε)=(19.2±2.1)×10-4. We find the KL-KS mass difference Δm=(5270±12) ×106hs-1 and the KS lifetime τS=(89. 62±0.05)×10-12s. We also measure several parameters that test CPT invariance. We find the difference between the phase of the indirect CP violation parameter ε and the superweak phase: φε- φSW=(0.40±0.56)°. We measure the difference of the relative phases between the CP violating and CP conserving decay amplitudes for K→π+π- (φ+-) and for K→π0π0 (φ00): Δφ=(0.30±0.35)°. From these phase measurements, we place a limit on the mass difference between K0 and K̄0: ΔM<4.8×10-19GeV/c2 at 95% C.L. These results are consistent with those of other experiments, our own earlier measurements, and CPT symmetry. © 2011 American Physical Society.
Type
journal article