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arXiv · hep-ex/0610023

Production of $σ$ in $ψ(2S)\to π^{+}π^{-}J/ψ$

BES Collaboration·M. Ablikim
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Abstract

Using 14M $ψ(2S)$ events accumulated by BESII at the BEPC, a Covariant Helicity Amplitude Analysis is performed for $ψ(2S)\toπ^+π^-J/ψ, J/ψ\to μ^+μ^-$. The $π^+π^-$ mass spectrum, distinctly different from phase space, suggests $σ$ production in this process. Two different theoretical schemes are used in the global fit to the data. The results are consistent with the existence of the $σ$. The $σ$ pole position is determined to be $(552^{+84}_{-106})-i(232^{+81}_{-72})$ MeV/$c^2$.

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BES Collaboration, M. Ablikim. 2006-11-20. Production of $σ$ in $ψ(2S)\to π^{+}π^{-}J/ψ$. https://doi.org/10.1016/j.physletb.2006.11.056

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