Puzzles in e??μ physics

摘要

I discuss some puzzles observed in exclusive e??μ-meson decays, concentrating on the large difference between the direct CP asymmetries in the e??μ0 a?’ e???a?“e????± and e??μ?± a?’ e???0e????± modes, the large e??μ0 a?’ e???0e???0 branching ratio, and the large deviation of the mixing-induced CP asymmetries in the $b a?’ sqar{q}$ penguins from those in the $b a?’ car{c}s$ trees.