论文标题
首先搜索弱辐射衰减$λ_c^+ \ toσ^+γ$和$ξ_c^0 \ toξ^0γ$
First search for the weak radiative decays $Λ_c^+ \to Σ^+ γ$ and $Ξ_c^0 \to Ξ^0 γ$
论文作者
论文摘要
我们首次介绍了使用980〜fb $^{ - 1} $的数据样本,该搜索$λ_C^+ \ toσ^+γ$和$ξ_c^0 \ to end \ξ^0γ$,由Belle检测器收集的980〜fb $^{ - 1} $。没有明显的$λ_c^+ \ toσ^+γ$或$ξ_c^0 \ toξ^0γ$信号。服用损失$λ_c^+ \至p k^ - π^+ $和$ξ_c^0 \至ξ^ - π^+ $作为归一化通道,上限为90 \%\%可信度的分支级分$ {\ cal b}(\ cal b}(λ_c^+ \ t to c^+ f to)的可信度水平为k^{ - }π^+)<4.0 \ times 10^{ - 3} $和$ {\ cal b}(ξ_c^0 \ toξ^0γ)/{\ cal b}(ξ_c^0 \ toξ_c^0 \ toξ^ - π^+)我们在绝对分支的$ {\ cal b}(λ_c^+ \至σ^+γ)<2.6 \ times 10^{ - 4} $和$ {\ cal b}(λ_c^+γ)<2.6 \ cal b} $ {λ_c^+ \ to cul B} $ {\ cal b} $和$ {\ cal b}(ξ_c^0 \ to to to to)10^0γ^$ 10^$ 10^ - 4
We present the first search for the weak radiative decays $Λ_c^+ \to Σ^+ γ$ and $Ξ_c^0 \to Ξ^0 γ$ using a data sample of 980~fb$^{-1}$ collected by the Belle detector operating at the KEKB asymmetric-energy $e^+e^-$ collider. There are no evident $Λ_c^+ \to Σ^+ γ$ or $Ξ_c^0 \to Ξ^0 γ$ signals. Taking the decays $Λ_c^+ \to p K^- π^+$ and $Ξ_c^0 \to Ξ^- π^+$ as normalization channels, the upper limits at 90\% credibility level on the ratios of branching fractions ${\cal B}(Λ_c^+ \to Σ^+ γ)/{\cal B}(Λ_c^+ \to p K^{-} π^+) < 4.0 \times 10^{-3}$ and ${\cal B}(Ξ_c^0 \to Ξ^0 γ)/{\cal B}(Ξ_c^0 \to Ξ^- π^+) < 1.2 \times 10^{-2}$ are determined. We obtain the upper limits at 90\% credibility level on the absolute branching fractions ${\cal B}(Λ_c^+ \to Σ^+ γ) < 2.6 \times 10^{-4}$ and ${\cal B}(Ξ_c^0 \to Ξ^0 γ) < 1.8 \times 10^{-4}$.