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Measurements of Direct CP Violation, CPT Symmetry, and Other Parameters in the Neutral Kaon System

KTeV Collaboration·A. Alavi-Harati
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Abstract

We present a series of measurements based on K -> pi+pi- and K -> pi0pi0 decays collected in 1996-1997 by the KTeV experiment (E832) at Fermilab. We compare these four K -> pipi decay rates to measure the direct CP violation parameter Re(e'/e) = (20.7 +- 2.8) x 10^-4. We also test CPT symmetry by measuring the relative phase between the CP violating and CP conserving decay amplitudes for K->pi+pi- (phi+-) and for K -> pi0pi0 (phi00). We find the difference between the relative phases to be Delta-phi = phi00 - phi+- = (+0.39 +- 0.50) degrees and the deviation of phi+- from the superweak phase to be phi+- - phi_SW =(+0.61 +- 1.19) degrees; both results are consistent with CPT symmetry. In addition, we present new measurements of the KL-KS mass difference and KS lifetime: Delta-m = (5261 +- 15) x 10^6 hbar/s and tauS = (89.65 +- 0.07) x 10^-12 s.

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KTeV Collaboration, A. Alavi-Harati. 2002-08-06. Measurements of Direct CP Violation, CPT Symmetry, and Other Parameters in the Neutral Kaon System. https://doi.org/10.1103/physrevd.67.012005%2010.1103%2Fphysrevd.70.079904

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