CAJ | 학술논문

对于e+e-→τ+τ-过程在阈值附近的截面,目前的理论计算精度已经达到10-4.基于理论截面的高精度计算,利用极大似然函数方法,重新拟合由eμ末态标记的τ+τ-事例的扫描数据,得到τ质量的测量结果为1776.98-0.51-0.13+0.44+0.12 MeV,其中第一项是统计误差,由拟合程序给出;第二项是系统误差,主要包含能量刻度,能散及本底估计等三方面的不确定性.
대우e+e-→τ+τ-과정재역치부근적절면,목전적이론계산정도이경체도10-4.기우이론절면적고정도계산,이용겁대사연함수방법,중신의합유eμ말태표기적τ+τ-사례적소묘수거,득도τ질량적측량결과위1776.98-0.51-0.13+0.44+0.12 MeV,기중제일항시통계오차,유의합정서급출;제이항시계통오차,주요포함능량각도,능산급본저고계등삼방면적불학정성.
Recently many theoretical calculations have been made for the cross section of e+e- → τ+τ- near the threshold, the accuracy of which is up to 10-4. Based on one of the calculations, the e μ-contained final state data are refitted by utilizing the technique once adopted by BES collaboration for τ mass measurement.The systematic uncertainties are analyzed again and the final result of τ mass is 1776.98-0.51-0.13+0.44+0.12MeV.