Measurement of the branching fractions of χcJ → π+π−π0π0 via ψ(3686) → γχcJ

A bstract Using (2712 . 4 ± 14 . 3) × 10 6 ψ (3686) events collected with the BESIII detector operating at BEPCII, the branching fractions of χ cJ → π + π − π 0 π 0 ( J = 0 , 1 , 2) are measured via the radiative transition ψ (3686) → γχ cJ . The results are ℬ( χ c 0 → π + π − π 0 π 0 ) = (3 . 10 ± 0 . 01 ± 0 . 14) × 10 − 2 , ℬ( χ c 1 → π + π − π 0 π 0 ) = (1 . 16 ± 0 . 01 ± 0 . 05) × 10 − 2 , and B ( χ c 2 → π + π − π 0 π 0 ) = (1 . 92 ± 0 . 01 ± 0 . 08) × 10 − 2 , where the first uncertainties are statistical and the second systematic. The dominant intermediate states are found to be χ cJ → ρ + ρ − . These results improve upon previous measurements with significantly enhanced precision.