The rare leptonic decays B_{s, d} → l⁺l⁻ (l = e, μ, τ) present an important base to analyse the flavour structure of the standard model (SM) and also become a potential source to dig out possible signatures of new physics (NP) beyond the SM. The muonic decay B_{s, d} → μ⁺μ⁻ has been observed at the LHC as well as the upper limits of branching ratios for other B_{s, d} → l⁺l⁻ decays have been updated recently. In this paper, using the χ² fitting method we have studied all these decay channels considering the effect of a Z^′ boson. Our analysing method reproduces the result of the muonic channel of B_s meson, hence we have used the same strategy for the other B_{s, d} → l⁺l⁻ decays.

稀土轻子衰变乙_小号，d  → 升⁺升^-  （升 =  ê，  μ，  τ）呈现的重要基地以分析标准模型的风味结构（SM）和也成为挖掘出的可能的签名的潜在来源SM以外的新物理（NP）。的μ介子衰变乙_小号，d  →  μ ⁺ μ ^-在LHC以及分支比对其他的上限已经观察到乙_小号，d  → 升⁺升⁻衰减最近已更新。在本文中，使用 χ ²拟合方法，我们已经研究所有考虑的效果这些衰变道Ž ^'玻色子。我们的分析方法再现的μ介子信道的结果乙_小号介子，因此我们已经用于其它相同的策略乙_小号，d  → 升⁺升^-衰变。