Liu Ming-Zhu, Pan Ya-Wen, Peng Fang-Zheng, Sánchez Mario Sánchez, Geng Li-Sheng, Hosaka Atsushi, Valderrama Manuel Pavon
School of Physics and Nuclear Energy Engineering, Beihang University, Beijing 100191, China.
Centre d'Études Nucléaires, CNRS/IN2P3, Université de Bordeaux, 33175 Gradignan, France.
Phys Rev Lett. 2019 Jun 21;122(24):242001. doi: 10.1103/PhysRevLett.122.242001.
A recent analysis by the LHCb Collaboration suggests the existence of three narrow pentaquarklike states-the P_{c}(4312), P_{c}(4440), and P_{c}(4457)-instead of just one in the previous analysis [the P_{c}(4450)]. The closeness of the P_{c}(4312) to the D[over ¯]Σ_{c} threshold and the P_{c}(4440) and P_{c}(4457) to the D[over ¯]^{*}Σ_{c} threshold suggests a molecular interpretation of these resonances. We show that these three pentaquarklike resonances can be naturally accommodated in a contact-range effective field theory description that incorporates heavy-quark spin symmetry. This description leads to the prediction of all the seven possible S-wave heavy antimeson-baryon molecules [that is, there should be four additional molecular pentaquarks in addition to the P_{c}(4312), P_{c}(4440), and P_{c}(4457)], providing the first example of a heavy-quark spin symmetry molecular multiplet that is complete. If this is confirmed, it will not only give us an impressive example of the application of heavy-quark symmetries and effective field theories in hadron physics, it will also uncover a clear and powerful ordering principle for the molecular spectrum, reminiscent of the SU(3)-flavor multiplets to which the light hadron spectrum conforms.
大型强子对撞机底夸克合作组最近的一项分析表明，存在三种窄的类五夸克态——Pₑ(4312)、Pₑ(4440)和Pₑ(4457)，而不是之前分析中仅有的一种[Pₑ(4450)]。Pₑ(4312)与D⁻Σₑ阈值接近，Pₑ(4440)和Pₑ(4457)与D⁻*Σₑ阈值接近，这表明这些共振态可作分子态解释。我们表明，这三种类五夸克共振态可以自然地纳入包含重夸克自旋对称性的接触程有效场论描述中。这种描述导致预测出所有七种可能的S波重反介子 - 重子分子态[也就是说，除了Pₑ(4312)、Pₑ(4440)和Pₑ(4457)之外，还应该有另外四个分子态五夸克]，提供了一个完整的重夸克自旋对称性分子多重态的首个例子。如果这一结果得到证实，它不仅将为我们提供重夸克对称性和有效场论在强子物理中应用的一个令人印象深刻的例子，还将揭示分子谱中一个清晰且强大的排序原则，这让人联想到轻强子谱所符合的SU(3)味多重态。
