论文标题
三角奇异性作为$ x_0（2900）$和$ x_1（2900）$的起源
Triangle singularity as the origin of $X_0(2900)$ and $X_1(2900)$ observed in $B^+\to D^+ D^- K^+$
论文作者
论文摘要
LHCB合作报告了从$ b^+\到d^+d^+d^ - k^+$ decay的$ d^ - k^+$不变质量分布中狭窄峰的观察。该峰通过两个共振$ x_0（2900）$和$ x_1（2900）$的参数化，并带有夸克内容$ \ bar {c} \ bar {s} ud $，他们的旋转量子量子数字分别为$ 0^+$和$ 1^ - $。我们研究了可能有助于$ b^+\ d^+d^ - k^+$衰减的拆卸过程。结果表明，$ d^{* - } k^{*+} $通过$χ_{c1} k^{*+} d^{* - * - } $ loop或$ \ bar {d} _ {1} _ {1}^{0} $ d_ {sj}^{+} \ bar {d} _ {1}^{0} k^{0} $ loop loop仿真$ x_0（2900）$和$ x_1（2900）$结构。这种现象是由于散射幅度的分析特性，其三角形奇异性位于物理边界附近。
The LHCb collaboration reported the observation of a narrow peak in the $D^- K^+$ invariant mass distributions from the $B^+\to D^+ D^- K^+$ decay. The peak is parameterized in terms of two resonances $X_0(2900)$ and $X_1(2900)$ with the quark contents $\bar{c}\bar{s}ud$, and their spin-parity quantum numbers are $0^+$ and $1^-$, respectively. We investigate the rescattering processes which may contribute to the $B^+\to D^+ D^- K^+$ decays. It is shown that the $D^{*-}K^{*+}$ rescattering via the $χ_{c1}K^{*+}D^{*-}$ loop or the $\bar{D}_{1}^{0}K^{0}$ rescattering via the $D_{sJ}^{+}\bar{D}_{1}^{0}K^{0}$ loop simulate the $X_0(2900)$ and $X_1(2900)$ structures. Such phenomena are due to the analytical property of the scattering amplitudes with the triangle singularities located to the vicinity of the physical boundary.
