论文标题
$λ_b\ toλ（\ topπ^ - ）\ ell^+\ ell^ - $中的时间反向不对称
Time-reversal asymmetries in $Λ_b \to Λ(\to p π^-)\ell^+\ell^-$
论文作者
论文摘要
我们研究了$λ_b\ toλ（\ topπ^ - ）\ ell^+ \ ell^ - $的衰减，并带有$ \ ell =（e，μ，τ）$。特别是，我们检查了具有偏振$λ_b$的完整角度分布，并确定时间反转的不对称或T-ODD可观察物。通过使用均匀的袋子型号，我们发现$λ_b\ toλ\ ell^+el^ - $的衰减分支分支为$（9.1 \ pm 2.5,7.9 \ pm 1.8，2.1 \ pm 0.2）\ pm 0.2 \ pm 0.2）此外，我们获得了$ a_ {fb}^{\ ell} = -0.369 \ pm 0.007 $和$ a_ {fb}^{h} = -0.333 \ pm 0.004 $，平均范围为$ 15 \ leq q^leq q^2 \ leq Q^2 \ leq 20〜 \ leq 20〜 \ fext {geev}^2 $。这些结果与当前的实验数据一致。我们还以$λ_b\ toλ（\ topπ^ - ）μ^+μ^ - $探索t-odd可观察结果，对新物理〜（np）敏感。明确地说，我们说明了T-ODD可观察到的当前实验测量有利于NP的存在，例如额外的$ z $ -Boson模型。
We study the decays of $Λ_b \to Λ(\to p π^-) \ell ^+ \ell^-$ with $\ell = (e, μ, τ)$. In particular, we examine the full angular distributions with polarized $Λ_b$ and identify the time-reversal asymmetries or T-odd observables. By using the homogeneous bag model, we find that the decay branching fractions of $Λ_b \to Λ\ell^+\ell^-$ are $(9.1\pm 2.5,7.9\pm 1.8, 2.1\pm 0.2)\times 10^{-7}$ for $\ell =(e, μ,τ)$, respectively. In addition, we obtain that $A_{FB}^{\ell} = -0.369\pm 0.007$ and $A_{FB}^{h}=-0.333\pm 0.004$, averaged in the range of $15 \leq q^2 \leq 20~ \text{GeV}^2$. These results are well consistent with the current experimental data. We also explore the T-odd observables in $Λ_b \to Λ(\to p π^-) μ^+ μ^-$, which are sensitive to new physics~(NP). Explicitly, we illustrate that the current experimental measurement from one of the T-odd observables favors the existence of NP, such as the extra $Z$-boson model.
