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Understanding the 0++ and 2++ charmonium(-like) states near 3.9 GeV
Teng Ji1, Xiang-Kun Dong1, Miguel Albaladejo2
1CAS Key Laboratory of Theoretical Physics, Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190, China; School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, China.
Science Bulletin
|March 13, 2023
Summary
This study proposes that observed charmonium states are hadronic molecules. Analysis of B decays and photon fusion reactions reveals four hidden-charm scalar molecular states, deepening understanding of charmonium spectra.
Area of Science:
- Particle Physics
- Quantum Chromodynamics
- Hadron Spectroscopy
Background:
- The nature of exotic charmonium states like X(3915) and X(3960) remains debated.
- Previous assignments of JPC=0++ to X(3915) in B+ decays require clarification.
Purpose of the Study:
- To investigate the relationship between X(3915) and χc2(3930).
- To determine if X(3960) is an S-wave Ds+Ds- hadronic molecule.
- To analyze coupled-channel effects in hidden-charm systems.
Main Methods:
- Analysis of experimental data from B decays and gamma-gamma fusion reactions.
- Coupled-channel analysis considering DD¯, Ds+Ds-, D*D¯*, and Ds*D¯* interactions.
- Inclusion of 0++ and 2++ states within the theoretical framework.
Main Results:
- The X(3915) and χc2(3930) are identified as the same state.
- The X(3960) is confirmed as an S-wave Ds+Ds- hadronic molecule.
- Four hidden-charm scalar molecular states with masses 3.73, 3.94, 3.99, and 4.23 GeV are predicted.
- Simultaneous reproduction of data across different processes is achieved.
Conclusions:
- The proposed assignments and molecular nature of these states are consistent with available data.
- The findings contribute to a comprehensive understanding of charmonium spectrum and charmed hadron interactions.
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