论文标题
一个新的激动的carmed baryon衰减的证据，将$σ_{c}（2455）^{0，++}π^{\ pm} $
Evidence of a new excited charmed baryon decaying to $Σ_{c}(2455)^{0,++} π^{\pm}$
论文作者
论文摘要
我们介绍了$ \ bar {b}^{0} \至σ_{c}（2455）^{0，++}π^{\ pm} \ bar {p} $衰变，基于$ 772 \ times 10^{6} {6} $ $ $ $ $ $ b \ b \ b \ b \ b \ b \ b \ b \ bar { $ e^+e^ - $ collider。 $σ_{c}（2455）^{0，++} $候选者是通过其衰变重建至$λ_{c}^{+}π^{\ mp} $和$λ__{c}^{+}^{+} $衰变的$ pk^{ - }π^{+}，〜pk_ {s}^{0}，$和$λπ^{+} $最终状态。相应的分支馏分被测量为$ {\ cal b}（\ bar {b}^{0} \ toσ_{c}（2455）^{0} {0}π^{+} {+} \ bar {p} \ bar {p}） b}（\ bar {b}^{0} \ toσ_{c}（2455）^{++}π^{ - } \ bar {p}）=（1.84 \ pm 0.11 \ pm 0.11 \ pm 0.12）\ pm 0.12）\ times 10^{ - 4} $，与世界平均值相一致，这是一致的准确性。在$ m_ {σ_{c}（2455）^{0，++}π^{\ pm}} $ spectrum中找到一个新结构，其显着性为$4.2σ$，包括系统的不确定性。该结构可能是一个激动的$λ_{c}^{+} $，并且被暂定命名为$λ_{c}（2910）^{+} $。它的质量和宽度分别为$（2913.8 \ pm 5.6 \ pm 3.8）$ mev/$ c^{2} $和$（51.8 \ pm20.0 \ pm 18.8）$ mev。 $λ_{c}（2910）^{+} $的分支分数的产物被测量为$ {\ cal b}（\ bar {b}^{0}^{0} \toλ_{c}（c}（c}（2910））（2910） b}（λ_{c}（2910）^{+} \ toσ_{c}（2455）^{0}π^{+}）=（9.5 \ pm 3.6 \ pm 1.6）\ times 10^{ - 6}} （2910）^{+} \ bar {p}）\ times {\ cal b}（λ_{c}（2910）^{+} \ toσ_{c}（c}（2455）^{++} {++}π^{ - }π^{ - } =（1.24 \ pm pm 0.35 $ 0.35} $ 10}在这里，第一个和第二个不确定性分别是统计和系统的。
We present the study of $\bar{B}^{0} \to Σ_{c}(2455)^{0,++} π^{\pm} \bar{p}$ decays based on $772\times 10^{6}$ $B\bar{B}$ events collected with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider. The $Σ_{c}(2455)^{0,++} $ candidates are reconstructed via their decay to $Λ_{c}^{+} π^{\mp}$ and $Λ_{c}^{+}$ decays to $pK^{-}π^{+},~pK_{S}^{0},$ and $Λπ^{+}$ final states. The corresponding branching fractions are measured to be ${\cal B}(\bar{B}^{0} \to Σ_{c}(2455)^{0} π^{+} \bar{p}) = (1.09 \pm 0.06 \pm 0.07)\times10^{-4}$ and ${\cal B}(\bar{B}^{0} \to Σ_{c}(2455)^{++} π^{-} \bar{p}) = (1.84\pm 0.11 \pm 0.12)\times 10^{-4}$, which are consistent with the world average values with improved precision. A new structure is found in the $M_{Σ_{c}(2455)^{0,++}π^{\pm}}$ spectrum with a significance of $4.2σ$ including systematic uncertainty. The structure is possibly an excited $Λ_{c}^{+}$ and is tentatively named $Λ_{c}(2910)^{+}$. Its mass and width are measured to be $(2913.8 \pm 5.6 \pm 3.8)$ MeV/$c^{2}$ and $(51.8\pm20.0 \pm 18.8)$ MeV, respectively. The products of branching fractions for the $Λ_{c}(2910)^{+}$ are measured to be ${\cal B}(\bar{B}^{0} \to Λ_{c}(2910)^{+}\bar{p})\times{\cal B}(Λ_{c}(2910)^{+} \to Σ_{c}(2455)^{0}π^{+}) = (9.5 \pm 3.6 \pm 1.6)\times 10^{-6}$ and ${\cal B}(\bar{B}^{0} \to Λ_{c} (2910)^{+}\bar{p})\times {\cal B}(Λ_{c}(2910)^{+} \to Σ_{c}(2455)^{++}π^{-}) = (1.24 \pm 0.35 \pm 0.10)\times 10^{-5}$. Here, the first and second uncertainties are statistical and systematic, respectively.
