Branching fraction measurements ofχc0andχc2toπ

Abstract

Using a sample of 1.06 × 10 8 ψ ′ decays collected by the BESIII detector, χ c0 and χ c2 decays into π 0 π 0 and ηη are studied. The branching fraction results are Br(χ c0 → π 0 π 0 ) = (3.23 ± 0.03 ± 0.23 ± 0.14) × 10 −3 , Br(χ c2 → π 0 π 0 ) = (8.8 ± 0.2 ± 0.6 ± 0.4) × 10 −4 , Br(χ c0 → ηη) = (3.44 ± 0.10 ± 0.24 ± 0.2) × 10 −3 , and Br(χ c2 → ηη) = (6.5 ± 0.4 ± 0.5 ± 0.3) × 10 −4 , where the uncertainties are statistical, systematic due to this measurement, and systematic due to the branching fractions of ψ ′ → γχ cJ , respectively. The results provide information on the decay mechanism of χ c states into pseudoscalars.

Observation of e+e−→ϕχc1 and ϕχ

“…The total systematic uncertainty due to PID efficiency is obtained with the same method, where the PID uncertainty for each charged track is taken as 1.0% [52]. The systematic uncertainty from photon reconstruction is determined to be 1.0% for each photon by studying the control sample of J/ψ → ρ 0 π 0 decays [53]. Since it is difficult to find an appropriate control sample to estimate the systematic uncertainty related to the kinematic fit and the vertex fit, we correct the chargedtrack helix parameters of the MC simulated events [54] to obtain a better match with the data sample.…”

Observation of a Neutral Structure near theDD¯*Mass Threshold ine+Ablikim1, Ачасов2, Ai3 et al. 2015Phys. Rev. Lett.Self Cite803390View full textAdd to dashboardCite

“…The uncertainties of tracking efficiency and particle identification for π AE and K AE are evaluated to be 1% per track [29,30]. The uncertainty in the photon-reconstruction efficiency is estimated to be about 1% per photon [31]. The efficiency difference of reconstructing the K S in MC simulations and in data is 4.0% [32].…”

“…The efficiency difference of reconstructing the K S in MC simulations and in data is 4.0% [32]. The uncertainty in π 0 reconstruction is 1% [31]. The systematic bias of the KF is estimated by using the track-parameter-correction method [33].…”

Study of two-photon decays of pseudoscalar mesons via J/ψ radiative decays

“…The difference in tracking efficiency between data and MC simulation is found to be 1% per track, which is taken as the uncertainty from the tracking efficiency. The photon detection efficiency is studied with a clean sample of J=ψ → ρ 0 π 0 [32]. The result shows that the difference of detection efficiency between data and MC simulation is 1% per photon.…”