A new decay mode of higher charmonium

Li-Ye Xiao,Shi-Lin Zhu,Xian-Hui Zhong,Xin-Zhen Weng,Qi-Fang Lü

doi:10.1140/epjc/s10052-018-6087-3

Li-Ye Xiao, Shi-Lin Zhu + Show 3 more

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https://doi.org/10.1140/epjc/s10052-018-6087-3

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Abstract

We calculate the Lambda _c{bar{Lambda }}_c partial decay width of the excited vector charmonium states around 4.6 GeV with the quark pair creation model. We find that the partial decay width of the Lambda _c{bar{Lambda }}_c mode can reach up to several MeV for psi (4S,~5S,~6S). In contrast, the partial Lambda _c{bar{Lambda }}_c decay width of the states psi (3D,~4D,~5D) is less than one MeV. If the enhancement Y(4630) reported by the Belle Collaboration in Lambda _c{bar{Lambda }}_c invariant-mass distribution is the same structure as Y(4660), the Y(4660) resonance is most likely to be a S-wave charmonium state.

Highlights

Since the Belle Collaboration reported the first member of the family of the charmonium-like states, X (3872), in 2003 [1], a series of charmonium-like states [2], called collectively X Y Z states, have been observed by several major experimental collaborations such as Babar, BESIII, LHCb, CLEO-c and so on
If the Y (4660) is a D-wave charmonium state, the partial decay width of the cc mode should be less than one MeV. (2) If the enhancement Y (4630) reported by Belle Collaboration in cc invariant-mass distribution is the same structure as Y (4660), the Y (4660) resonance is most likely to be a S-wave charmonium state
We have considered six excited vector charmonium states around 4.6 Gev and investigated their cc partial decay width

Summary

Introduction

Since the Belle Collaboration reported the first member of the family of the charmonium-like states, X (3872), in 2003 [1], a series of charmonium-like states [2], called collectively X Y Z states, have been observed by several major experimental collaborations such as Babar, BESIII, LHCb, CLEO-c and so on. The Y (4660) resonance, as the most massive state among the charmonium-like states at present, was first reported by the Belle Collaboration [4] in the process e+e− → γISRπ +π −ψ(2S) associated with the Y (4360) resonance in 2007. Its mass and width were determined to be M = Later, this state was confirmed by BaBar Collaboration [5] in the π +π −ψ(2S) invariant-mass distribution with new data on the e+e− → γISRπ +π −ψ(2S) progress with the mass. If the Y (4660) is a D-wave charmonium state, the partial decay width of the cc mode should be less than one MeV. (2) If the enhancement Y (4630) reported by Belle Collaboration in cc invariant-mass distribution is the same structure as Y (4660), the Y (4660) resonance is most likely to be a S-wave charmonium state.

An introduction of the 3 P0 model

Calculations and results

S wave

D wave

The effect of β

Summary