#
Status of X(1835) and $p\overline{p}$ Interaction from Chiral Symmetry

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## Abstract

**:**

## 1. Introduction

## 2. $X\left(1835\right)$ and $p\overline{p}$ Interaction

#### 2.1. Historical Development: Working with Effective Range Expansion

#### 2.2. Updates: More Refined Treatment of Interaction and FSI

#### 2.3. Potential Experimental Searches

## 3. Mesonic Decay of $X\left(1835\right)$

## 4. Conclusions and Outlook

## Acknowledgments

## Author Contributions

## Conflicts of Interest

## References

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**Figure 1.**Difference for the predicted $\overline{p}p$ spectrum in the decay $J/\psi \to \gamma \overline{p}p$ resulting from the WM approximation (cf. Equation (5)) and the DWBA (cf. Equation (7) below). The $\overline{p}p$ potential in $I=1{,}^{1}{S}_{0}$ from the A(OBE) model was used as an input. The solid line denotes the result from DWBA while the dash-dotted curve corresponds to WM approximation. Data are taken from Refs. [1,39,40] and normalized to the one given by BES2012 [40]. Figure from Ref. [13].

I = 0 | I = 1 | |
---|---|---|

Chiral NLO [26] | −0.21 − i (1.20 $\xb7\xb7\xb7$ 1.21) | (1.03 $\xb7\xb7\xb7$ 1.04) − i (0.56 $\xb7\xb7\xb7$ 0.58) |

Chiral NNLO [26] | −0.21 − i (1.21 $\xb7\xb7\xb7$ 1.22) | (1.02 $\xb7\xb7\xb7$ 1.04) − i (0.57 $\xb7\xb7\xb7$ 0.61) |

Jülich model D [48] | −0.23 − i 1.01 | 0.99 − i 0.58 |

Paris2009 [49] | 1.115 − i 0.856 | 0.684 − i 0.473 |

Grach et al. [45] | 1.2 − i 0.9 | 0.1 − i 0.4 |

Pirner et al. [46] | 1.1 − i 0.4 | −0.3 − i 0.8 |

**Table 2.**The calculated hadronic level shifts and widths in hyperfine states of antiprotonic hydrogen ($\overline{p}$ H) for ${}^{1}{S}_{0}$ partial wave. The ones corresponding to Grach et al. and Pirner et al. are deduced from the scattering lengths shown by them in Refs. [45,46]. The experimental information is taken from Refs. [50,51].

$\mathbf{\Delta}\mathit{E}$ (eV) | Γ (eV) | |
---|---|---|

Chiral NLO [26] | −(306 $\xb7\xb7\xb7$ 361) | (1528 $\xb7\xb7\xb7$ 1553) |

Chiral NNLO [26] | −(302 $\xb7\xb7\xb7$ 361) | (1545 $\xb7\xb7\xb7$ 1589) |

Jülich model D [48] | −330 | 1380 |

Paris2009 [49] | −778 | 1038 |

Grach et al. | −564 | 1128 |

Pirner et al. | −608 | 1042 |

Experiment [50] | −740 ± 150 | 1600 ± 400 |

[51] | −440 ± 75 | 1200 ± 250 |

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**MDPI and ACS Style**

Liu, Y.-F.; Kang, X.-W.
Status of X(1835) and *Symmetry* **2016**, *8*, 14.
https://doi.org/10.3390/sym8030014

**AMA Style**

Liu Y-F, Kang X-W.
Status of X(1835) and *Symmetry*. 2016; 8(3):14.
https://doi.org/10.3390/sym8030014

**Chicago/Turabian Style**

Liu, Yong-Feng, and Xian-Wei Kang.
2016. "Status of X(1835) and *Symmetry* 8, no. 3: 14.
https://doi.org/10.3390/sym8030014