论文标题
$ b^ - \ to k^-π^0x（3872）$对$ x（3872）$质量的反应和敏感性的三角奇异性
Triangle singularity in the $B^-\to K^-π^0X(3872)$ reaction and sensitivity to the $X(3872)$ mass
论文作者
论文摘要
我们已经对$ b^ - \至k^ - π^0 x（3872）$通过三角形机制进行反应进行了研究：$ b^ - \ to k^ - d^{*0} \ bar d^{*0} $; $ d^{*0} \至π^0 d^0 $; $ d^0 \ bar d^{*0} \ to x（3872）$。我们表明，这种机制在$π^0 x（3872）$中产生了一个三角形的奇异性，对于$ x（3872）$质量的非常狭窄的窗口，围绕目前的测量值，并表明质量位置和质量分布的形状对$ x（3872）$质量敏感，可以对质量进行质量，以适应这种质量，以适应该反应，以适应该量的衡量所述，以适应该反应的效果。特别是，我们指出，$ x（3872）$质量相对于$ d^0 \ bar d^{*0} $阈值可以从$π^0x $ line形状的不对称性中提取。
We have done a study of the $B^- \to K^- π^0 X(3872)$ reaction by means of a triangle mechanism via the chain of reactions: $B^- \to K^- D^{*0}\bar D^{*0}$; $D^{*0} \to π^0 D^0$; $D^0\bar D^{*0}\to X(3872)$. We show that this mechanism generates a triangle singularity in the $π^0 X(3872)$ invariant mass for a very narrow window of the $X(3872)$ mass, around the present measured values, and show that the peak positions and the shape of the mass distributions are sensitive to the $X(3872)$ mass, such that a measurement of the reaction can serve to improve on the present values of this mass. In particular, we point out that the $X(3872)$ mass relative to the $D^0\bar D^{*0}$ threshold may be extracted from the asymmetry of the $π^0X$ line shape.
