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Modern particle physics experiments usually rely on highly complex and large-scale spectrometer devices. In high energy physics experiments, visualization helps detector design, data quality monitoring, offline data processing, and has great potential for improving physics analysis. In addition to the traditional physics data analysis based on statistical methods, visualization provides unique intuitive advantages in searching for rare signal events and reducing background noises. By applying the event display tool to several physics analyses in the BESIII experiment, we demonstrate that visualization can benefit potential physics discovery and improve the signal significance. With the development of modern visualization techniques, it is expected to play a more important role in future data processing and physics analysis of particle physics experiments. [ABSTRACT FROM AUTHOR]

The BESIII experiment, serving as the only operational τ -charm factory, has made significant strides in advancing our understanding of baryons. Notably, it has achieved a remarkable series of breakthroughs encompassing baryon decays, mass spectra, and production mechanisms. This mini review serves as the one-stop shop for readers who would like to know what has been studied about baryons at BESIII, and of course, it could be a starting point for studies about baryons at BESIII or even a super-Tau-Charm factory. [ABSTRACT FROM AUTHOR]

We present a search for the lepton flavor violating decay J/ψ → e±μ∓ using 8.998 × 109J/ψ events collected with the BESIII detector at the BEPCII e+e− storage ring. No excess of signal above background is observed; we therefore set an upper limit on the branching fraction of ℬ (J / ψ → e ± μ ∓) < 4.5 × 10 − 9 at the 90% confidence level. Improving the previous best result by a factor of more than 30, this measurement places the most stringent limit to date on lepton flavor violation in the heavy quarkonium sector. [ABSTRACT FROM AUTHOR]

The cross-sections of and have been measured by BESIII experiment. A new resonance is observed in the two decay modes. A combined fit is performed to the two cross-sections. 's parameters are determined to be , , where the first uncertainties are statistical and the second systematic. The ratio is also obtained and it indicates that 's main decay modes maybe . We determine the lower limit of its leptonic decay width of around 150 eV, which can be compared with the theoretical expectations of different models. These information may help in understanding the nature of this state. [ABSTRACT FROM AUTHOR]

An improved scheme to implement integral non-linearity (INL) correction of time measurements in the Beijing Spectrometer III Endcap Time-of-Flight (BESIII ETOF) upgrade system is presented in this paper. During upgrade, multi-gap resistive plate chambers (MRPC) are introduced as ETOF detectors which increases the total number of time measurement channels to 1728. The INL correction method adopted in BESIII TOF proved to be of limited use, because the sharply increased number of electronic channels required for reading out the detector strips degrade the system configuration efficiency severely. Furthermore, once installed into the spectrometer, BESIII TOF electronics do not support the TDCs’ nonlinearity evaluation online. In this proposed method, INL data used for the correction algorithm are automatically imported from a non-volatile read-only memory (ROM) instead of from data acquisition software. This guarantees the real-time performance and system efficiency of the INL correction, especially for the ETOF upgrades with massive number of channels. Besides, a signal that is not synchronized to the system 41.65 MHz clock from BEPCII is sent to the frontend electronics (FEE) to simulate pseudo-random test pulses for the purpose of online nonlinearity evaluation. Test results show that the time measuring INL errors in one module with 72 channels can be corrected online and in real time. [ABSTRACT FROM AUTHOR]

Based on BOSS framework, using the 106 M inclusive ψ(3686) events produced by BESIII data production group, we studied the sensitivity of C parity violated channel J/ψ → γ φ at BESIII. In the inclusive γ(3686) sample without signal channel, we determined the upper limit observed number at 90% C. L.. We obtained the upper limit branching fraction of J/γ → γ φ as 6. 1 x 10-7. The results show the sensitivity can reach 10-7 at the proposed data set will be collected at BESIII. [ABSTRACT FROM AUTHOR]

The Beijing Spectrometer III (BESIII) superconducting solenoid magnet, which is running in the Beijing Electron Positron Collider II (BEPC-II), is an important part of BESIII and provides a 1 Tesla field in the main drift chamber. A 3-D mapping device with three 3-D probes was fabricated to measure the field components of Bz, Br and BΦ. The mapping of the magnetic field of the BESIII superconducting solenoid magnet is presented, with the accelerator interaction region magnets located inside the BESIII solenoid excited to different current values. A set of polynomials, and a few trigonometric-Bessel terms are used to fit the data. The measurements and the functional model agree to 5 Gauss within the main drift chamber tracking volume at nominal field values. [ABSTRACT FROM AUTHOR]

This paper describes the control electronics for the time of flight (TOF) monitor system of BESIII. A 9U VME module is designed as the interface between the TOF monitor laser box and BESIII data acquisition system. It takes charge of enabling the laser source, sending trigger signals to the laser driver, controlling the optic path, and measuring the charge and arrival time of pulses from two reference phototubes. The module also sends a Level 1 trigger to the TOF readout system, after each trigger pulse to the laser source. The interface and control logic are implemented in one Altera field-programmable gate array, and signals from the reference PMTs of the laser system are digitized with the CERN HPTDC technique. A series of experimental tests show that the time resolution of the monitor electronics is better than 25 ps, and the relative methodical error of the charge measurement is less than 0.5% after quadratic fitting. The TOF monitor system was installed at the end of 2007 and has been operating continuously since then. A total time resolution of about 70 ps and a charge resolution of about 4% of the TOF counters have been obtained during field monitor tests. [ABSTRACT FROM AUTHOR]

BESIII is a high precision, general purpose detector for the high luminosity e+e- collider, BEPCII, running at the tau-charm energy region. Its design and current status of construction is presented. [ABSTRACT FROM AUTHOR]

Within the chamonium-threshold QCD theory, the two-photon spectroscopies of charmonia will provide the unique test on the non-perturbative treatment. With the high luminosity and excellent detector in the BESIII experiment, the two-photon transition from ψ(2S) to J/ψ is firstly observed and the preliminary result of the measurement of the branching fraction is given. [ABSTRACT FROM AUTHOR]

The Beijing Spectrometer III (BESIII) detector magnet running in Beijing electron positron collider reached its nominal current successfully in 2008. The 3.39 m diameter, 3.91 m long superconducting solenoid magnet (SSM) provides a 1 Tesla central magnetic field. It was inner wound with aluminum stabilized NbTi/Cu cable and conduction--cooled with forced flow of two phase helium circulating in a tracing tube. A thermal shield was conduction--cooled with liquid nitrogen in the cryostat. This paper reports the experience of the test of the BESIII detector magnet. [ABSTRACT FROM AUTHOR]