Search for the weak decay η′→K±π∓ and precise measurement of the branching fraction B(J/ψ→φη′)
CitationKolcu, O. B., ... (2016).Search for the weak decay η′→K±π∓ and precise measurement of the branching fraction B(J/ψ→φη′). Physical Review D. 93, 1-8.
We present the first search for the rare decay of η′ into K±π∓ in J/ψ→ϕη′, using a sample of 1.3×109 J/ψ events collected with the BESIII detector. No significant signal is observed, and the upper limit at the 90\% confidence level for the ratio B(η′→K±π∓)B(η′→γπ+π−) is determined to be 1.3×10−4. In addition, we report the measurement of the branching fraction of J/ψ→ϕη′ to be (5.10±0.03(stat.)±0.32(syst.))×10−4, which agrees with previous results from BESII.