Cpt Results from Ktev

The powerful probe of CPT symmetry originates from this coherent superposition. There is also a fortunate conspiracy of the kaon masses, lifetimes, and decay widths, allowing one to look experimentally for very small CPT violating effects that may be present. While many probes in the neutral kaon sector are available, I will mention only ones relevant to KTeV. Table 1 shows the experimental observables (and their definitions) that are sensitive to possible CPT violating effects. The traditional framework to parameterize possible neutral kaon CPT violation can be found in the literature. It is a phenomological approach: one which spells out all possible CPT effects without much consideration to the microscopic details of the theory. Nevertheless, one can derive the experimental signatures that would imply CPT violation. CPT violating effects in the K → 2π and K̄ → 2π amplitudes can reveal themselves in the KL → 2π decay mode. This is possible since the latter is the coherent superposition of those 2 amplitudes. CPT violation of this type is called “direct” since it is tied to a decay amplitude. Indirect CPT violating effects such as the difference between MK0 and MK̄0 could be seen in the comparison of φ+− to φSW . Direct CPT violating effects may also show up in the semileptonic decay modes KL → eπν (Ke3). The two Ke3 final states,