Abstract
Using the large hadroproduced charm sample collected in experiment E791 at Fermilab, we report the first directly measured constraint on the decay-width difference for the mass eigenstates of the - system. We obtain our result from lifetime measurements of the decays and , under the assumption of CP invariance, which implies that the CP eigenstates and the mass eigenstates are the same. The lifetime of (the CP-even final state) is , and the lifetime of (an equal mixture of CP-odd and CP-even final states) is . The decay-width difference is . We relate these measurements to measurements of mixing in the neutral -meson system.
- Received 10 March 1999
DOI:https://doi.org/10.1103/PhysRevLett.83.32
©1999 American Physical Society