How the X(5568) Challenges Our Understanding of QCD
Abstract
We discuss the X(5568) particle recently announced by the D0 Collaboration. Several types of models were proposed to explain this structure in the literature. As pointed out by Burns and Swanson (arXiv:1603.04366), none of them provides a satisfactory description of the observation. We provide additional arguments using general properties of QCD, and conclude that the observation of the X(5568), if confirmed, poses serious challenges to our understanding of nonperturbative QCD.
Supported by DFG and National Natural Science Foundation of China Through Funds Provided to the Sino-German CRC 110 “Symmetries and the Emergence of Structure in QCD” (National Natural Science Foundation of China under Grant No. 11261130311), by the Thousand Talents Plan for Young Professionals, and the Chinese Academy of Sciences President's International Fellowship Initiative under Grant No. 2015VMA076- Publication:
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Communications in Theoretical Physics
- Pub Date:
- May 2016
- DOI:
- 10.1088/0253-6102/65/5/593
- arXiv:
- arXiv:1603.06316
- Bibcode:
- 2016CoTPh..65..593G
- Keywords:
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- High Energy Physics - Phenomenology;
- High Energy Physics - Experiment;
- Nuclear Theory
- E-Print:
- 5 pages. Typos removed, a wrong statement corrected, conclusions unchanged