Rare decays B̄s,d0 → l+l− in a top quark two-Higgs-doublet model

In the framework of T2HDM, we calculated the new physics contributions involving neutral Higgs bosons to the branching ratios of s,d0 → l+l− (l = e, μ) decays. Comparing the theoretical predictions with the experimental upper-limits, we found that (a) The data of Br(s,d0 → l+l−) give the upper bound on tanβ: tanβ ≤ 22, while Br(s,d0 → l+l−) give tanβ ≤ 12 for fixed δ = 0o, mH+ = 350 GeV, mHo = 160 GeV, mHo = 115 GeV and mAo = 120 GeV; (b) A light neutral Higgs boson mass mHo (mAo) less than 50 GeV (120 GeV) is excluded by the data of branching ratios for s,d0 → l+l− (l = μ) decays with tanβ = 10; (c) The bounds on mHo and tanβ, or mAo and tanβ are strongly correlated: a smaller (larger) tanβ means a lighter (heavier) neutral Higgs boson.