摘要
We study strong decays of the possible fully-charm tetraquarks recently observed by LHCb,and calculate their relative branching ratios through the Fierz rearrangement.Together with our previous QCD sum rule study,our results suggest that the broad structure around 6.2–6.8 GeV can be interpreted as an S-wave cccc tetraquark state with JPC=0++or 2++,and the narrow structure around 6.9 GeV can be interpreted as a P-wave one with JPC=0-+or 1-+.These structures were observed in the di-J=w invariant mass spectrum,and we propose to confirm them in the di-gc;J/ψhc;ηcχc0,and ηcχc1channels.We also propose to search for their partner states having the negative charge-conjugation parity in the J/ψηc;J/ψχc0;J/ψχc1,and ηchc channels.
最近LHCb实验国际合作组在双J/ψ末态中观测到了两个奇特的结构,它们都包含两个粲夸克和两个反粲夸克,是全/纯粲四夸克态的候选者,这是实验上首次观测到由四个重夸克结合在一起而构成的奇特强子态.本文研究了这两个结构的强衰变性质,并通过Fierz变换的方法计算了它们的衰变分支比.结合之前的QCD求和规则工作,作者认为:实验上发现的位于6.2~6.8 GeV之间的宽结构可以被很好的解释为S波全/纯粲四夸克态,量子数为J(PC)=0(++)或2(++),建议在双ηc末态中对其进行确认;实验上发现的位于6.9 GeV附近的窄结构可以被很好的解释为P波全/纯粲四夸克态,量子数为J(PC)=0(-+)或1(-+),建议在双ηc和J/ψ-hc等末态中对其进行确认.此外,以上两个结构都具有正的C宇称(C=+),建议在J/ψ-hc等末态中进一步寻找具有负的C宇称(C=-)的全/纯粲四夸克态.
作者
Hua-Xing Chen
Wei Chenc
Xiang Liu
Shi-Lin Zhu
陈华星;陈伟;刘翔;朱世琳(School of Physics,Southeast University,Nanjing 210094,China;School of Physics,Beihang University,Beijing 100191,China;School of Physics,Sun Yat-Sen University,Guangzhou 510275,China;School of Physical Science and Technology,Lanzhou University,Lanzhou 730000,China;Research Center for Hadron and CSR Physics,Lanzhou University and Institute of Modern Physics of CAS.Lanzhou 730000,China;School of Physics and State Key Laboratory of Nuclear Physics and Technology,Peking University.Beijing 100871.China;Collaborative Innovation Center of Quantum Matter,Beijing 100871,China;Center of High Energy Physics,Peking UniversityBeijing 100871,China)
基金
supported by the National Natural Science Foundation of China (11722540 and 11975033)
the Chinese National Youth Thousand Talents Program
the China National Funds for Distinguished Young Scientists (11825503)
the National Program for Support of Top-notch Young Professionals
the Fundamental Research Funds for the Central Universities。
