论文标题
四体baryonic $ b \ to {\ bf b_1 \ bar b'1 b_2 \ bar b'2} $衰减
Four-body baryonic $B\to{\bf B_1\bar B'_1 B_2 \bar B'_2}$ decays
论文作者
论文摘要
储层计算是预测湍流的有力工具，其简单的架构具有处理大型系统的计算效率。然而，其实现通常需要完整的状态向量测量和系统非线性知识。我们使用非线性投影函数将系统测量扩展到高维空间，然后将其输入到储层中以获得预测。我们展示了这种储层计算网络在时空混沌系统上的应用，该系统模拟了湍流的若干特征。我们表明，使用径向基函数作为非线性投影器，即使只有部分观测并且不知道控制方程，也能稳健地捕捉复杂的系统非线性。最后，我们表明，当测量稀疏、不完整且带有噪声，甚至控制方程变得不准确时，我们的网络仍然可以产生相当准确的预测，从而为实际湍流系统的无模型预测铺平了道路。
LHCb has recently reported the first observation of a four-body baryonic $B\to{\bf B_1\bar B'_1 B_2\bar B'_2}$ decay, where ${\bf B_1\bar B'_1}$ and ${\bf B_2\bar B'_2}$ represent the two pairs of octet baryon states. In our classification, the measured $\bar B^0\to p\bar p p\bar p$ decay is a tree dominated process via internal $W$-boson emission, whose branching fraction is explained as small as $2.2\times 10^{-8}$. We investigate for the first time the phenomenology of other tree and penguin dominated $B\to{\bf B_1\bar B'_1 B_2\bar B'_2}$ decays, and predict the presence of a double threshold effect, manifested as two peaks around $m_{\bf B_1\bar B'_1}\sim m_{\bf B_1}+m_{\bf\bar B'_1}$ and $m_{\bf B_2\bar B'_2}\sim m_{\bf B_2}+m_{\bf\bar B'_2}$ in the invariant mass spectra of ${\bf B_1\bar B'_1}$ and ${\bf B_2\bar B'_2}$, respectively. Moreover, we predict the following branching fractions: ${\cal B}(B^-\to n\bar p p\bar p)=(1.7^{+0.4}_{-0.2}\pm 0.1^{+0.7}_{-0.4})\times 10^{-7}$, ${\cal B}(B^-\to Λ\bar p p\bar p)=(7.4^{+0.6}_{-0.2}\pm 0.03^{+3.6}_{-2.6})\times 10^{-7}$, and ${\cal B}(\bar B^0_s\to Λ\bar Λp\bar p)=(1.9^{+0.3}_{-0.1}\pm 0.01^{+1.1}_{-0.6})\times 10^{-7}$, which are accessible to experimental facilities.
