We study bound-state effects on the t over(t, ̄) production cross section in the threshold region at hadron colliders. The bound-state effects are important particularly at the LHC where the gluon fusion is the dominant subprocess. Due to the formation of t over(t, ̄) resonances in the J = 0 color-singlet channel of g g → t over(t, ̄) and the large width of the top quark, the t over(t, ̄) invariant-mass distribution peaks at a few GeV below the t over(t, ̄) threshold, and it is significantly enhanced over the naive NLO prediction until several GeV above the threshold. We present predictions of the t over(t, ̄) invariant-mass distribution which incorporate both the bound-state effects and initial-state radiations up to NLO. The bound-state effects would lead to a substantial deformation of top-quark kinematical distributions in the threshold region.
|Number of pages||6|
|Journal||Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics|
|Publication status||Published - 2008 Aug 7|