W+-H+ INTERFERENCE AND PARTIAL WIDTH ASYMMETRY IN TOP-QUARK AND TOP ANTIQUARK DECAYS

We reexamine the question of a possible difference in the partial decay widths of t and t̄, induced by an intermediate scalar boson H+ with CP-violating couplings. The interference of W+ and H+ exchanges is analyzed by constructing the 2×2 propagator matrix of the W+-H+ system, and determining its absorptive part in terms of fermion loops. Results are obtained for the partial rate difference in the channels t→bl+νl and t→bcs̄, which fulfill explicitly the constraints of CPT invariance. These results are contrasted with those in previous work. © 1995 The American Physical Society.