### Abstract

We use QCD sum rules to study the recently observed resonance-like structures in the π^{+} χ_{c 1} mass distribution, Z_{1}^{+} (4050) and Z_{2}^{+} (4250), considered as D^{* +} over(D, ̄)^{* 0} and D_{1}^{+} over(D, ̄)^{0} + D^{+} over(D, ̄)_{1}^{0} molecules with the quantum number J^{P} = 0^{+} and J^{P} = 1^{-}, respectively. We consider the contributions of condensates up to dimension eight and work at leading order in α_{s}. We obtain m_{D* D*} = (4.15 ± 0.12) GeV, around 100 MeV above the D^{*} D^{*} threshold, and m_{D1 D} = (4.19 ± 0.22) GeV, around 100 MeV below the D_{1} D threshold. We conclude that the D^{* +} over(D, ̄)^{* 0} state is probably a virtual state that is not related with the Z_{1}^{+} (4050) resonance-like structure. In the case of the D_{1} D molecular state, considering the errors, its mass is consistent with both Z_{1}^{+} (4050) and Z_{2}^{+} (4250) resonance-like structures. Therefore, we conclude that no definite conclusion can be drawn for this state from the present analysis.

Original language | English |
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Pages (from-to) | 29-39 |

Number of pages | 11 |

Journal | Nuclear Physics A |

Volume | 815 |

Issue number | 1-4 |

DOIs | |

Publication status | Published - 2009 Jan 1 |

### All Science Journal Classification (ASJC) codes

- Nuclear and High Energy Physics

## Fingerprint Dive into the research topics of 'Can the π<sup>+</sup> χ<sub>c 1</sub> resonance structures be D<sup>*</sup> over(D, ̄)<sup>*</sup> and D<sub>1</sub> over(D, ̄) molecules?'. Together they form a unique fingerprint.

## Cite this

^{+}χ

_{c 1}resonance structures be D

^{*}over(D, ̄)

^{*}and D

_{1}over(D, ̄) molecules?

*Nuclear Physics A*,

*815*(1-4), 29-39. https://doi.org/10.1016/j.nuclphysa.2008.10.012