| Popis: |
CLEO's large sample of ♥(4S) decays has yielded measurements of the various exclusive semileptonic decays: ( B 0 , B − ) → (D + , D ∗ + )l \ gn l and (D 0 , D ∗ 0 )l \ gn l . These imply the ratio of the charged and neutral lifetimes to be τ − / τ 0 = 0.89 ± 0.23. The (model dependent) vector/pseudoscalar decay-width ratio is found to be 2.6 ± 1.1. In contrast to this important but not unexpected result is the observation of ♥(4S) decays to non- B B states, as evidenced by φ's beyond the kinematic limit for B B decay. No compelling explanation is known for the branching ratio of greater than 0.2 percent. |
