三喷注事件中的胶子喷注和夸克喷注的性质(英文)

用蒙特卡洛方法研究了 91.2GeVe+e- 碰撞产生的 3喷注事件 .用三个喷注之间的夹角来标识各个喷注 ,分别计算了三个喷注的能量及其能量分布 ,并在相同能量下计算了三个喷注的多重数、横动量及其分布 .通过与能量相同的 2喷注事件中单夸克喷注的上述性质的比较 ,得到了从 3喷注事件中挑选胶子喷注和夸克喷注的一种简便方法 .挑选出来的胶子喷注和夸克喷注在性质上与QCD的理论预言一致 ,并且胶子和夸克喷注的平均多重数比值的计算结果与实验观测值符合 .

PROPERTIES OF GLUON ANDQUARK JETS IN THREE-JET EVENTS

The 3 jet events produced in e\++e\+- collisions at 91.2 GeV has been studied using Monte Carlo method.The three angles between the jets are used to identify the individual jet in 3 jet events.The energy distributions,the mean particle multiplicities,the mean transverse momenta of the three jets in equal energy bins and their distributions have been calculated.Comparing with the corresponding results from the quark jets in 2 jet events with equal energies,a simple method to select the gluon and quark jets from 3 jet events is obtained.The properties of the gluon and quark jets being selected using the introduced method are in qualitative agreement with the expectations of perturbative QCD.The calculations of the ratio of mean particle multiplicity of gluon relative to quark jets have been carried out.The results agree with the experimental results from several research groups,indicating that the method proposed to select the gluon and quark jets from 3 jet events is reasonable.