Measurement of branching fractions of $\psi(3686)\to \phi\eta^\prime, \phi f_1(1285)$ and $\phi \eta(1405)$

Abstract

Using a sample of 448.1×106ψ(3686) events collected with the BESIII detector, we perform a study of the decay ψ(3686)→ϕπ+π−η. The branching fraction of ψ(3686)→ϕη′ is determined to be (1.51±0.16±0.12)×10−5, which is consistent with the previous measurement but with significantly improved precision. The resonances f1(1285) and η(1405) are clearly observed in the π+π−η mass spectrum with statistical significances of 18σ and 9.7σ, respectively. The corresponding product branching fractions are measured to be B(ψ(3686)→ϕf1(1285),f1(1285)→π+π−η)=(1.03±0.10±0.09)×10−5 and B(ψ(3686)→ϕη(1405),η(1405)→π+π−η)=(8.46±1.37±0.92)×10−6.