f2(1270) Resonance Formation in the π+π-Final State in Two-Photon Collisions at BELLE

• Main Author: 林盛文
• Other Authors: 郭榮升
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/25114671830272863063

碩士 === 國立高雄師範大學 === 物理學系 === 89 === Abstract In this thesis,the Monte-Carlo studies and the real data analysis, collected by BELLE laboratory of KEKB accelerator in Japan, of two-photon physics via e+e-→e+e-γγ→e+e-f2(1270)→e+e-π+π-have been presented. The advantage of EFC is that it can be used to tag the two-photon events, and we can get the partial width with less systematic error. We selected the pions mainly used the ACC-TOF-CDC(atc) package and examined its effects by dEdx vs log10P and TOF mass. We fitted mass at 1.2346±0.0004GeV/c2 with width of 0.167±0.002GeV/c2 for the integrated luminosity 5.2fb-1 of no-tag events, and got 323263 signal events in the analysis of real data. The overall detecting efficiency is 43.86% and the estimated number is 382400. We fitted mass at 1.24±0.003GeV/c2 with width of 0.198±0.01GeV/c2 for the integrated luminosity 4.45fb-1 of single-tag(FEFC-tagged) signal events, and got 8179 signal events in the analysis of real data. The acceptance of the FEFC detector is estimated to be 14.18%, and the total efficiency of the detectors is 42.81%. According the calculation of real data analysis, the average Q2 value is around 0.86GeV2 and the photon form factor which is 0.407 should be include in the cross section calculation. The estimated number is 7528.