CP asymmetries induced by particle widths: Application to top quark decays

Jul, 1991
11 pages
Published in:
  • Phys.Rev.Lett. 67 (1991) 1979-1981
Report number:
  • MAD-PH-664,
  • MSU-TH-05,
  • BNL-46462

Citations per year

199119992007201520220246810
Abstract: (APS)
An on-shell unstable particle produced in a tree-level process, such as W in t→qW, induces a CP violating signal through its width. This effect arises from an Im(tree)×Re(loop) type of interference. Among t→qq’q¯ processes (e.g., t→bcb¯) proceeding either through the tree-level t→qW or the one-loop t→q’+(virtual g) reactions, the CP asymmetry is largest for the case t→dcd¯ and is of scrO(η/λ2) in Wolfenstein’s parametrization. The resulting effects are found to be small in the standard model, but are much larger than those obtained for radiative top-quark decays. We also briefly discuss B decays where such a mechanism may cause CP violation in, for example, b→se+e−.
  • top
  • top: decay modes
  • decay modes: quark
  • mass: top
  • top: mass
  • top: branching ratio
  • CP: violation
  • decay: asymmetry
  • asymmetry: decay
  • W: width