共查询到8条相似文献,搜索用时 0 毫秒
1.
The absolute energy calibration with photons from π0's for the BESⅢ EMC is discussed. Using 3 million hadronic events, the preliminary results are presented. Precision of about 1% in the photon energy measurement is obtained from crossing check using photons in ψ(2S)→γχc1,2(1P). 相似文献
2.
曹学香 李卫东 Roy A. Briere 刘春雷 毛泽普 陈申见 邓子艳 何康林 黄性涛 黄彬 黄艳萍 贾卢魁 季晓斌 李秀荣 刘春燕 刘怀民 马秋梅 马想 邱进发 王大勇 伍灵慧 吴智 袁野 张学尧 赵川 张瑶 邹佳恒 《中国物理 C》2010,34(12):1852-1859
The Beijing Spectrometer Ⅲ(BESⅢ)is a general-purpose detector used for the study of τ-charm physics at the Beijing Electron-Positron Collider Ⅱ(BEPC Ⅱ).This paper presents our studies of the dE/dx measurement in the drift chamber of BESⅢ,which is important for the identification of charged particles.Corrections applied to the dE/dx measurement in data reconstruction are discussed.After our current dE/dx calibration,a resolution of about 6% has been obtained for minimum ionization particles,and a 3σ K/πseparation is obtained for momenta up to 760 MeV/c.These results meet the design goals of the BESⅢ drift chamber. 相似文献
3.
吴智 刘建北 秦中华 伍灵慧 陈昌 陈元柏 陈玛丽 陈锡辉 董明义 关北菊 黄杰 江晓山 金艳 李飞 李仁英 李小男 雷广坤 刘荣光 罗小兰 马骁妍 盛华义 孙汉生 唐晓 王岚 王靓 徐美杭 张建 章红宇 张银鸿 赵豫斌 赵平平 朱科军 朱启明 庄保安 《中国物理 C》2010,34(7):983-987
The BESⅢ drift chamber and its subsystems need a cosmic-ray test after the chamber construction to check the chamber construction quality,testing the joint operation of the whole system and the performance of the chamber.The noise performance,drift time and charge measurements,and the scanning of channels were examined specifically.The preliminary results of the test indicate that the whole system works well. 相似文献
4.
贾卢魁 毛泽普 李卫东 曹国富 曹学香 邓子艳 何康林 刘春燕 刘怀民 刘秋光 马秋梅 马想 邱进发 田浩来 王纪科 伍灵慧 袁野 臧石磊 张长春 张雷 张瑶 朱凯 邹佳恒 《中国物理 C》2010,34(12):1866-1873
In order to overcome the difficulty brought by the circling charged tracks with transverse momentum less than 120 MeV in the BESⅢ Main Drift Chamber (MDC), a specialized method called TCurlFinder was developed. This tracking method focuses on the charged track reconstruction under 120 MeV and possesses a special mechanism to reject background noise hits. The performance of the package has been carefully checked and tuned by both Monte Carlo data and real data. The study shows that this tracking method could obviously enhance the reconstruction efficiency in the low transverse momentum region, providing physics analysis with more and reliable data. 相似文献
5.
Primary vertex reconstruction is crucial to estimate the beam profile in collision experiments. We study the principle of an iterative process, called the Kalman filter method, and apply it to primary vertex reconstruction at BESⅢ. A Newton procedure to find the zero point of the distance function's gradient is used for primary vertex finding in 3-dimensional space. Results are obtained based on raw data at BESⅢ. 相似文献
6.
The kinematic properties of two-body decay near τ threshold are studied according to the special capacity of the BEPC accelerator and the BESⅢ detector.Explicitly presented are the transformations of energy and momentum of hadronic particles between different reference frames,and the corresponding distributions.A brand new method is proposed to obtain the energy spread of the accelerator by fitting the energy distribution of hadron from τ semi-leptonic decays. 相似文献
7.
We present the physics program of the open charm and heavy cc states above the DD production energy threshold, which will be studied with the BES-Ⅲ detector at the BEPC- Ⅱ collider in the coming years. Based on some full Monte Carlo simulations with the BES-Ⅲ detector, we predict the accuracy levels on measuring some physical quantities related to D^0, D^+ and Ds^+ decays as well as some non-charmed decays of the heavy cc states. 相似文献