Decays of pentaquarks in hadrocharmonium and molecular scenarios
Decays of pentaquarks in hadrocharmonium and molecular scenarios
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DOI：
10.1103/physrevd.98.114037
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发表时间：
2018-11
影响因子：
5
通讯作者：
M. I. Eides;V. Petrov
中科院分区：
文献类型：
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作者：
M. I. Eides;V. Petrov
我们考虑在hadrocharmonium和分子的情况下，隐藏的魅力LHCb五夸克的衰变。在这两幅图中，LHCb五夸克态本质上都是非相对论性的束缚态。我们开发了一个半相对论框架计算的部分衰变宽度，使最终粒子是相对论的。使用这种方法，我们计算的衰变宽度在hadrocharmonium和分子图片。分子隐魅五夸克是由粲强子和反粲强子的松散束缚态构成的。计算结果表明，分子五夸克态主要衰变为开粲态。分子五夸克态衰变到隐魅态的强抑制可以用分子五夸克态相对较大的尺寸来定性解释。被解释为激发粲偶素$\psi '$和核子的松散束缚态的hadrocharmonium五夸克的衰变模式是完全不同的。这种时间主导衰变到隐藏的魅力状态，但魅力交换的衰变抑制弱于相应的分子情况。较弱的抑制解释了较大的结合能和相应的小尺寸的hadrocharmonium五夸克。这些结果与部分衰变宽度的实验数据相结合，可以让我们弄清楚五夸克的两种理论方案中的哪一种（如果有的话）是自然选择的。
We consider decays of the hidden charm LHCb pentaquarks in the hadrocharmonium and molecular scenarios. In both pictures the LHCb pentaquarks are essentially nonrelativistic bound states. We develop a semirelativistic framework for calculation of the partial decay widths that allows the final particles to be relativistic. Using this approach we calculate the decay widths in the hadrocharmonium and molecular pictures. Molecular hidden charm pentaquarks are constructed as loosely bound states of charmed and anticharmed hadrons. Calculations show that molecular pentaquarks decay predominantly into states with open charm. Strong suppression of the molecular pentaquark decays into states with hidden charm is qualitatively explained by a relatively large size of the molecular pentaquark. The decay pattern of hadrocharmonium pentaquarks that are interpreted as loosely bound states of excited charmonium $\psi'$ and nucleons is quite different. This time dominate decays into states with hidden charm, but suppression of the decays with charm exchange is weaker than in the respective molecular case. The weaker suppression is explained by a larger binding energy and respectively smaller size of the hadrocharmonium pentaquarks. These results combined with the experimental data on partial decay widths could allow to figure out which of the two theoretical scenarios for pentaquarks (if either) is chosen by nature.