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  • Letter
  • Open Access

Producing fully charm structures in the J/ψ-pair invariant mass spectrum

Jun-Zhang Wang1,2,‡, Dian-Yong Chen3,4,†, Xiang Liu1,2,4,5,*, and Takayuki Matsuki6,§

  • 1School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, China
  • 2Research Center for Hadron and CSR Physics, Lanzhou University Institute of Modern Physics of CAS, Lanzhou 730000, China
  • 3School of Physics, Southeast University, Nanjing 210094, China
  • 4Lanzhou Center for Theoretical Physics, Lanzhou University, Lanzhou 730000, China
  • 5Key Laboratory of Theoretical Physics of Gansu Province and Frontiers Science Center for Rare Isotopes, Lanzhou University, Lanzhou 730000, China
  • 6Tokyo Kasei University, 1-18-1 Kaga, Itabashi, Tokyo 173-8602, Japan

  • *Corresponding author. xiangliu@lzu.edu.cn
  • †chendy@seu.edu.cn
  • ‡wangjzh2012@lzu.edu.cn
  • §matsuki@tokyo-kasei.ac.jp
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Phys. Rev. D 103, L071503 – Published 23 April, 2021

DOI: https://doi.org/10.1103/PhysRevD.103.L071503

Abstract

Focusing on the novel phenomenon of several enhancement structures existing in the invariant mass spectrum of a J/ψ pair, which was reported by LHCb very recently, we find a new dynamical mechanism based on the special reactions, where all the possible combinations of a double charmonium directly produced by a proton-proton collision are transitioned into final-state J/ψJ/ψ. Under this framework, totally different from the popular tetraquark explanation, the LHCb experimental data of the line shape of the J/ψ-pair invariant mass spectrum can be well mimicked. Since the proposed dynamical mechanism is universal enough, we further predict the possible enhancement structures existing in the ϒ(1S)-pair invariant mass spectrum, which may provide a realistic approach to test the new mechanism proposed in this work and form a new task for the LHCb and CMS experiments.

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Phys. Rev. D 103, L071503– Published 23 April, 2021
  • Received 1 September 2020
  • Accepted 24 March 2021
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