Perturbative Quantum Chromodynamics α_(s)^(4)-Order Corrections to the Ratio R for τ Decay  

作　　者：B.P.Nigam 

机构地区：[1]Department of Physics&Astronomy,Box 871504,Arizona State University Tempe,Arizona,USA 85287-1504

出　　处：《Chinese Physics Letters》1998年第10期711-712,共2页中国物理快报（英文版）

摘　　要：The perturbative quantum chromodynamics correction to the semihadronic decay rate R of the heavy leptonτwas expressed by Braaten as an expansion in powers ofαs to orderαs3.Braaten had found theα_(s)^(4)order correction to be significant and conjectured that theα_(s)^(4)order corrections might also be significant.Braaten et al.later corrected theα_(s)^(4)-order result.We have extended the analytic calculations to orderαs4;it involves an unknown constant K3 which occurs inαs4 order.In order to estimate the effect ofα_(s)^(4)order correction,we have chosen K3 to range from-1000 to+1000 and we find that the value of R changes by about-11%to+10%,respectively,compared to the value of R=3.5 obtained toα_(s)^(4)-order result.

关 键 词：CORRECTION α DYNAMICS 

分 类 号：O57[理学—粒子物理与原子核物理]