Width effects on near threshold decays of the top quark t -> cWW,cZZ and of neutral Higgs bosons

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Bar-Shalom S., Eilam G., Frank M., Turan İ.

PHYSICAL REVIEW D, vol.72, no.5, 2005 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 72 Issue: 5
  • Publication Date: 2005
  • Doi Number: 10.1103/physrevd.72.055018
  • Journal Name: PHYSICAL REVIEW D
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Middle East Technical University Affiliated: No


The nonzero widths of heavy particles become significant when they appear in the final state of any decay occurring just around its kinematical threshold. To take into account such effects, a procedure, called the convolution method, was proposed by Altarelli, Conti, and Lubicz. We expand their study which included only threshold effects for t -> bWZ in the standard model. We discuss finite width effects in the three-body decays t -> cWW,cZZ and A(0)(h(0))-> tbW in the type III version of a two-Higgs doublet model. In particular, we find a substantial enhancement in the decay t -> cZZ, which brings its branching ratio to BR(t -> cZZ)similar to 10(-3), and in the decay A(0)-> tbW, which, unlike the h(0) case, becomes competitive with the A(0) two-body decay modes.