Based on the 225 million J/ψ events and 106 million ψ(3686) events collected with the BESIII detector at the BEPCII facility, the recent results on light hadron spectroscopy are presented, including ...the confirmation of X(1835) and observation of two new resonances in J/ψ→ γπ+π−η′, observation of a structure X(1870) in J/ψ→ωπ+π−η, and the partial wave analysis of ψ(3686)→${\rm{p\bar p\pi }}^0 $.
A novel field-programmable gate array (FPGA)based online tracking algorithm for helix track reconstruction in a solenoidal field, developed for the Antiproton Annihilations at Darmstadt spectrometer, ...is described. Employing the straw tube tracker detector with 4636 straw tubes, the algorithm includes a complex track finder and a track fitter. Implemented in VHDL, the algorithm is tested on a Xilinx Virtex-4 FX60 FPGA chip with different types of events, at different event rates. A processing time of 7 μs per event for an average of six charged tracks is obtained. The momentum resolution is about 3% (4%) for p t (p z ) at 1 GeV/c. Comparing with the algorithm running on a CPU chip (single core Intel Xeon E5520 at 2.26 GHz), an improvement of three orders of magnitude in processing time is obtained. The algorithm can handle severe overlapping of events, which are typical for interaction rates above 10 MHz.
An Electron-ion collider in China (EicC) has recently been proposed, for imaging the precise and detailed internal structures of hadrons, understanding the emergent properties of nucleon (such as the ...nucleon mass and spin) and the emergence of nuclear medium effect, and studying the exotic hadronic states. By exploiting the abundant “pion cloud” around the proton, an experiment of measuring the pion structure is suggested, and it is one of the physics highlights at the EicC facility. In this paper, we present a simulation study of the proposed pion structure experiment. At EicC, the pion structure information is accessed via the leading-neutron tagged deep inelastic scattering—the widely acknowledged Sullivan process of pion exchange with small momentum transfer. We briefly discuss the theoretical framework of our event generator and the current design of the experimental setup for the experiment. We then evaluate the statistical errors of the pion structure function that would be extracted from the proposed measurement under the integrated luminosity of 50 fb
-
1
. The sensitivity and precision to pion parton distribution functions are also demonstrated with a global fit. The precise quark distributions of the pion can be achieved at EicC in the range of
0.05
<
x
π
<
0.95
, and the pion gluon distribution also can be constrained by the global fit of the pseudo-data at various
Q
2
.
Electron-ion collider in China Anderle, Daniele P.; Bertone, Valerio; Cao, Xu ...
Frontiers of physics,
12/2021, Letnik:
16, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Lepton scattering is an established ideal tool for studying inner structure of small particles such as nucleons as well as nuclei. As a future high energy nuclear physics project, an Electron-ion ...collider in China (EicC) has been proposed. It will be constructed based on an upgraded heavy-ion accelerator, High Intensity heavy-ion Accelerator Facility (HIAF) which is currently under construction, together with a new electron ring. The proposed collider will provide highly polarized electrons (with a po- larization of 80%) and protons (with a polarization of 70%) with variable center of mass energies from 15 to 20 GeV and the luminosity of (2-3)×10 33 cm −2*s −1. Polarized deuterons and Helium-3, as well as unpolarized ion beams from Carbon to Uranium, will be also available at the EicC.
The main foci of the EicC will be precision measurements of the structure of the nucleon in the sea quark region, including 3D tomography of nucleon; the partonic structure of nuclei and the parton interaction with the nuclear environment; the exotic states, especially those with heavy flavor quark contents. In addition, issues fundamental to understanding the origin of mass could be addressed by measurements of heavy quarkonia near-threshold production at the EicC. In order to achieve the above-mentioned physics goals, a hermetical detector system will be constructed with cutting-edge technologies.
This document is the result of collective contributions and valuable inputs from experts across the globe. The EicC physics program complements the ongoing scientific programs at the Jefferson Laboratory and the future EIC project in the United States. The success of this project will also advance both nuclear and particle physics as well as accelerator and detector technology in China.
First results of the RPC commissioning at BESIII Xie, Yuguang; Zhang, Jiawen; Chen, Jin ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
02/2009, Letnik:
599, Številka:
1
Journal Article
Recenzirano
The commissioning of the RPC-based muon detector in the BESIII experiment has been carried out. The RPC modules, front-end electronics, online and offline software of the muon system have been ...studied. The detector performances including efficiency, counting rate, noise ratio, spacial resolution, dark current, and muon charge ratio were obtained by cosmic ray data with and without magnetic field. The new operating high voltage and threshold were chosen after the scan experiment. The long-term stability of the BESIII RPCs made of bakelite without oil treatment was studied.
Charm quark production and its hadronization in ep and eA collisions at the future Electron-Ion Collider in China (EicC) will help us understand the quark/gluon fragmentation processes and the ...hadronization mechanisms in the nuclear medium, especially within a poorly constrained kinematic region (\(x<0.1\)). In this paper, we report a study on the production of charmed hadrons, \(D^0\) and \(\Lambda_c^+\), reconstructed with a dedicated GEANT4 simulation of vertex\(\,\&\,\)tracking detectors designed for EicC. The \(\Lambda_c^+\)/\(D^0\) ratios as functions of multiplicity and \(p_T\), as well as the \(D^0\) double ratio are presented with projected statistical precision.
The Electron-Ion Collider in China (EicC) has been proposed to study the
inner structure of matter and fundamental laws of strong interactions. In this
paper, we will present a conceptual design of ...the tracking system based on the
state-of-art silicon detector and Micro-Pattern Gaseous Detector at the EicC
and demonstrate that it will enable us to reconstruct charm hadron with good
significance, hence study gluonic parton distribution functions in nucleons and
nuclei, as well as gluon helicity distributions. The impact study using
reweighting techniques shows that the impact of the EicC will be mainly in the
large $x$ region. It complements similar physics programs at the Electron-Ion
Collider at Brookhaven National Laboratory.
The Electron-Ion Collider in China (EicC) has been proposed to study the inner structure of matter and fundamental laws of strong interactions. In this paper, we will present a conceptual design of ...the tracking system based on the state-of-art silicon detector and Micro-Pattern Gaseous Detector at the EicC and demonstrate that it will enable us to reconstruct charm hadron with good significance, hence study gluonic parton distribution functions in nucleons and nuclei, as well as gluon helicity distributions. The impact study using reweighting techniques shows that the impact of the EicC will be mainly in the large \(x\) region. It complements similar physics programs at the Electron-Ion Collider at Brookhaven National Laboratory.
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