论文标题
$λ_c^+\ to {} pk_s^0k_s^0 $和$λ_C^+\ to {} pk_s^0η$的分支分数的测量
Measurement of branching fractions of $Λ_c^+\to{}pK_S^0K_S^0$ and $Λ_c^+\to{}pK_S^0η$ at Belle
论文作者
论文摘要
我们介绍了一项单一的cabibbo抑制衰减$λ_c^+\ to {} pk_s^0k_s^0 $和Cabibbo最喜欢的衰减$λ_c^+\ to {} pk_s^0η$,基于980 $ \ rm fb^pelter-pelter-pelt the-rm fb^{ - 1} $ e^+e^ - $ collider。我们测量其分支相对于$λ_c^+\ to {} pk_s^0 $:$ \ Mathcal {b}(λ_c^+\ to {} pk_s^0k_s^0)/\ Mathcal {b} 0.04)\ times 10^{ - 2}} $和$ \ Mathcal {b}(λ_c^+\ to {} pk_s^0η)/\ Mathcal {b}(λ_c^+\ to {} pk_s^0) 10^{ - 1}} $。结合世界平均$ \ MATHCAL {B}(λ_c^+\ to {} pk_s^0)$,我们具有绝对的分支分数:$ \ nathcal {b}(λ_c^+\ \ \ to {} pk_s^0k_s^0k_s^0k_s^0) 10^{ - 4}} $和$ \ MATHCAL {B}(λ_c^+\ to {} pk_s^0η)= {(4.35 \ pm 0.10 \ pm 0.20 \ pm 0.22 \ pm 0.22)\ times 10^{ - 3}}} $。第一个和第二个不确定性分别是统计和系统的,而第三个不确定性源于$ \ Mathcal {b}(λ_c^+\ to {} pk_s^0)$的不确定性。第一次观察到模式$λ_C^+\ to {} pk_s^0k_s^0 $,并且具有$> \!10σ$的统计意义。 $λ_C^+\ to {} pk_s^0η$的分支分数已经测量,精度比以前的结果提高了三倍,并且发现与世界平均水平一致。
We present a study of a singly Cabibbo-suppressed decay $Λ_c^+\to{}pK_S^0K_S^0$ and a Cabibbo-favored decay $Λ_c^+\to{}pK_S^0η$ based on 980 $\rm fb^{-1}$ of data collected by the Belle detector, operating at the KEKB energy-asymmetric $e^+e^-$ collider. We measure their branching fractions relative to $Λ_c^+\to{}pK_S^0$: $\mathcal{B}(Λ_c^+\to{}pK_S^0K_S^0)/\mathcal{B}(Λ_c^+\to{}pK_S^0)={(1.48 \pm 0.08 \pm 0.04)\times 10^{-2}}$ and $\mathcal{B}(Λ_c^+\to{}pK_S^0η)/\mathcal{B}(Λ_c^+\to{}pK_S^0)={(2.73\pm 0.06\pm 0.13)\times 10^{-1}}$. Combining with the world average $\mathcal{B}(Λ_c^+\to{}pK_S^0)$, we have the absolute branching fractions: $\mathcal{B}(Λ_c^+\to{}pK_S^0K_S^0) = {(2.35\pm 0.12\pm 0.07 \pm 0.12 )\times 10^{-4}}$ and $\mathcal{B}(Λ_c^+\to{}pK_S^0η) = {(4.35\pm 0.10\pm 0.20 \pm 0.22 )\times 10^{-3}}$. The first and second uncertainties are statistical and systematic, respectively, while the third ones arise from the uncertainty on $\mathcal{B}(Λ_c^+\to{}pK_S^0)$. The mode $Λ_c^+\to{}pK_S^0K_S^0$ is observed for the first time and has a statistical significance of $>\!10σ$. The branching fraction of $Λ_c^+\to{}pK_S^0η$ has been measured with a threefold improvement in precision over previous results and is found to be consistent with the world average.