在φ→3γ衰变末态分析中的运用  

Analysis of ΦDecay to 3γ Final States with the TELESIS

作　　者：许国发[1] 童国梁[1] 黄秀萍[1] 吕峰[1] 俞国威[1] 

机构地区：[1]中国科学院高能物理研究所,北京100039

出　　处：《高能物理与核物理》2002年第5期462-470,共9页High Energy Physics and Nuclear Physics

基　　金：国家自然科学基金资助~~

摘　　要：介绍了介子工厂 (DAΦNE)KLOE组的数据分析中运动学拟合程序TELESIS的运用 .利用KLOE 2 0 0 0年在e+e- 对撞能量Ecm =1 0 2 0MeV获取的部分数据开展→γη→ 3γ和→γπ0 → 3γ的分析 ,得到介子的产生截面σe+ e- →=( 4.0 4± 0 .0 4± 0 .2 4 ) μb ,以及→γπ0 → 3γ的分截面σ→γπ0 →3γ=( 5.3± 0 .3± 0 .6)nb .这些结果与理论预言以及俄国新西伯利亚的VEPP(CMD 2 ,SND ,ND各探测器 )的相应结果一致 .DAΦNE (Double Annular Φ factory for Nice Experiment) is the Frascati(Italy) electron positron collider operating at the energy of 510 MeV, a rather low energy with respect to the other existing factories. DAΦNE includes two collision points, and KLOE detector is located at one of these points. The KLOE detector is designed primarily for the goal of detecting direct CP violation in K 0 decays with a sensitivity of ～10 -4 in R ( ε′/ε ), with a vast amount of other physics subjects.  radiative dacays, especially its pure neutral final states are very important subjects to test the Chiral Perturbation Theory approach both in the anomalous and non anomalous sectors. In this paper, a new kinematic fit method--TELESIS--is used for the data analysis of  radiative decay →γη→3γ and →γπ 0→3γ based on a part of 2000' data collected by KLOE detectors in DAΦNE, the  produced cross section and the partial cross section of e +e -→→γπ 0→3γ have been obtained as follows: σ e +e -→ =(4.04±0.04±0.24)μb, σ e +e -→→γπ 0→3γ =(5.3±0.3±0.6)nb. These results are in good agreement with that of VEPP and theoretical predictions.

关 键 词：末态分析 TELESIS 运动学拟合 φ辐射衰变 截面 φ介子工厂 DAφNE 正负电子对撞机 

分 类 号：O572.21[理学—粒子物理与原子核物理]