Related papers: Trigger efficiencies at BES III
Using a dedicated data sample taken in 2018 on the $J/\psi$ peak, we perform a detailed study of the trigger efficiencies of the BESIII detector. The efficiencies are determined from three representative physics processes, namely…
Using $(10087 \pm 44) \times 10^6$ $J/\psi$ events collected with the BESIII detector in 2009, 2012, 2018 and 2019, the tracking efficiency of charged pions is studied using the decay $J/\psi \rightarrow \pi^+ \pi^- \pi^0$. The systematic…
Using inclusive decays of the $\rm J/\psi$, a precise determination of the number of $\rm J/\psi$ events collected with the BESIII detector is performed. For the two data sets taken in 2009 and 2012, the numbers of $\rm J/\psi$ events are…
A method to estimate efficiency of event start time determination at BESIII is developed. This method estimates the efficiency at the event level by combining the efficiencies of various tracks ($e$, $\mu$, $\pi$, K, $p$, $\gamma$) in a…
Using 58 million $J/\psi$ and 14 million $\psi(2S)$ events collected by the BESII detector at the BEPC, branching fractions or upper limits for the decays $J/\psi$ and $\psi(2S) \to \Lambda \bar{\Lambda} \pi^0$ and $\Lambda \bar{\Lambda}…
A measurement of the number of $J/\psi$ events collected with the BESIII detector in 2009 and 2012 is performed using inclusive decays of the $J/\psi$ . The number of $J/\psi$ events taken in 2009 is recalculated to be $(223.7\pm1.4)\times…
The efficiencies for electron and positron tracking and identification in the BESIII experiment are investigated with the radiative Bhabha process $e^+e^-\rightarrow e^+e^-\gamma$ from the data samples collected at the center-of-mass…
Based on $J/\psi$ events collected with the BESIII detector, with corresponding Monte Carlo samples, the tracking efficiency and its systematic uncertainty are studied using a control sample of $J/\psi \to p \overline p \pi^+ \pi^-$.…
The new observation of X(1835)is reported using 58 million $\jpsi$ events collected at BES II detector. We also present the measurements of J/\Psi and eta_c decays, of them some are the first measurements and some improve the precision in…
Using J/psi -> mu^+ mu^- decays from a sample of approximately 4 million psi(2S) events collected with the BESI detector, the branching fractions of psi(2S) -> eta J/psi, pi^0 pi^0 J/psi, and anything J/psi normalized to that of psi(2S) ->…
The number of $J/\psi$ events collected with the BESIII detector at the BEPCII from June 12 to July 28, 2009 is determined to be $(225.3\pm2.8)\times10^{6}$ using $J/\psi \rightarrow inclusive$ events, where the uncertainty is the…
BESIII is a new state-of-the-art 4pi detector at the recently upgraded BEPCII two-ring e+e- collider at the Institute of High Energy Physics in Beijing. It has been in operation for three years, during which time it has collected the…
A study of the electron identification and selection efficiency of the L1 Trigger algorithm has been performed using the combined ECAL/HCAL test beam data. A detailed discussion of the electron isolation and its impact on the selection…
In a talk at an IHEP-Beijing symposium celebrating the 50th anniversary of the discovery of the J/$\psi$, I reminisced about some of the interesting phenomena that were observed in J/$\psi$ decays in the BES, BESII, and BESIII detectors…
Based on a sample of 5.8X 10^7 J/psi events taken with the BESII detector, the branching fractions of J/psi--> 2(pi+pi-)eta and J/psi-->3(pi+pi-)eta are measured for the first time to be (2.26+-0.08+-0.27)X10^{-3} and…
The numbers of $\psi(3686)$ events accumulated by the BESIII detector for the two rounds of data taking during 2009 and 2012 are determined to be $(107.0\pm0.8)\times 10^6$ and $(341.1\pm 2.1)\times 10^6$, respectively, by counting…
Multiquark searches have been a hot topic in recent years. Some threshold enhancements were observed during the analysis of 58M $\jpsi$ events collected by BES II detector. These enhancements can't be explained by the standard model and may…
We report the first observation of the decay J/psi --> 3 gamma. The signal has a statistical significance of 6 sigma and corresponds to a branching fraction of B(J/psi --> 3 gamma) = (1.2 +- 0.3 +- 0.2) x 10^-5, in which the errors are…
The performance of the ATLAS muon trigger system is evaluated with proton-proton ($pp$) and heavy-ion (HI) collision data collected in Run 2 during 2015-2018 at the Large Hadron Collider. It is primarily evaluated using events containing a…
The world's largest sample of Jpsi events collected at BESIII detector offers a unique opportunity to investigate eta and eta' physics via the Jpsi radiative or hadronic decays with unprecedented precision. In recent years the BESIII…