ORKA is a proposed experiment to measure the K+ -> pi+nunubar branching ratio with 5% precision using the Fermilab Main Injector high-intensity proton source. The detector design is based on the BNL E787/E949 experiments, which detected seven K+ -> p
i+nunubar candidate events. ORKA is expected to acheive two orders of magnitude improvement in sensitivity relative to the BNL experiments as a result of enhancements to the beam line and the detector acceptance. Precise measurement of the K+ -> pi+nunubar branching ratio with the same level of uncertainty as the well-understood Standard Model prediction allows for sensitivity to new physics at and beyond the LHC mass scale. Detector R&D, simulation-based optimization of the experiment design, and preparation of the experiment location are underway.
We present precise measurements of CP and CPT symmetry based on the full dataset of K to 2pi decays collected by the KTeV experiment at FNAL. We measure the direct CP violation parameter Re(epsilon/epsilon) = (19.2 pm 2.1)x10-4. We also report the KL
-KS mass difference, the KS lifetime, the phase of epsilon, and the phase difference (phi00)-(phi+-). These results are consistent with other experimental results and with CPT symmetry.
