arXiv subjects
Publications and source records attributed to Shuang-Shi Fang.
Using $(10087 \pm 44) \times 10^6$ $J/ψ$ events collected with the BESIII detector in 2009, 2012, 2018 and 2019, the tracking efficiency of charged pions is studied using the decay $J/ψ\rightarrow π^+ π^- π^0$. The systematic uncertainty of the tracking efficiency and the corresponding correction factors for charged pions are evaluated, in bins of transverse momentum and polar angle of the charged pions.
The light unflavoured meson $η/η^{\prime}$ decays are valuable for testing non-perturbative quantum chromodynamics and exploring new physics beyond the Standard Model. This paper describes a series of event generators, including $η/η^{\prime}\toγl^{+}l^{-}$, $η/η^{\prime}\toγπ^{+}π^{-}$, $η^{\prime}\toωe^{+}e^{-}$, $η\toπ^{+}π^{-}π^{0}$, $η/η^{\prime}\toπ^{0}π^{0}π^{0}$, $η^{\prime}\toηππ$ and $η^{\prime}\toπ^{+}π^{-}π^{+}π^{-}/π^{+}π^{-}π^{0}π^{0}$, which have been developed for investigating $η/η^\prime$ decay dynamics. For most of these generators, their usability has been validated in BESIII analyses for determining the detection efficiency, and background studies. The consistency between data and Monte Carlo shows that these generators work well in the BESIII simulation, and will also be useful for ongoing BESIII analyses and other experiments for studying $η/η^\prime$ physics.
The Time-Of-Flight system consisting of plastic scintillation counters plays an important role for particle identification in the BESIII experiment at the BEPCII double ring $e^+e^-$ collider. Degradation of the detection efficiency of the barrel TOF system has been observed since the start of physical data taking and this effect has triggered intensive and systematic studies about aging effects of the detector. The aging rates of the attenuation lengths and relative gains are obtained based on the data acquired in past several years. This study is essential for ensuring an extended operation of the barrel TOF system in optimal conditions.
We present physics opportunities and topics with the $s\bar{s}$ states (strangeonia) that can be studied with the BESIII detector operating at the BEPCII collider. Though the $ϕ$ and $η/η^\prime$ states have long been established experimentally, only a handful of strangeonia are well known, in contrast to the rich $c\bar{c}$ charmoium system. An overview of the $s\bar{s}$ states and their experimental status is presented in this paper. The BESIII experiment has collected the world's largest samples of $J/ψ$, $ψ(2S)$, $ψ(3770)$, and direct $e^+e^-$ annihilations at energies below the $J/ψ$ and above 3.8\,GeV, and will continue to accumulate high quality, large integrated luminosity in the $τ$-charm energy region. These data, combined with the excellent performance of the BESIII detector, will offer unprecedent opportunities to explore the $s\bar{s}$ system. In this paper we describe the experimental techniques to explore strangeonia with the BESIII detector.% at the BEPCII.
This paper introduces the calibration of the time-to-distance relation for the BESIII drift chamber. The parameterization of the time-to-distance relation is presented. The studies of left-right asymmetry and the variation with the entrance angle are performed. The impact of dead channels on the time-to-distance relation is given special attention in order to reduce the shifts of the measured momenta for the tracks passing near dead cells. Finally we present the spatial resolution (123 μm) for barrel Bhabha events (|cosθ|<0.8) from J/ψ data taken in 2012.