The shower shape of n,n,p,p,K+,π+ and photons,generated by JPCIAE code for 5.5 TeV/A 208Pb+208Pb collisions,incident on the ALICE photon spectrometer(PHOS),is analyzed with the principal component analysis(PCA) method.The efficiency dependence of purity for the photon discrimination is simulated for the deposited energy ranges 0.5-2 GeV,2-10 GeV,10-50 GeV and 50-100 GeV.The result shows that in the energy range of 0.5 to 100 GeV,the efficiency of the photon identification can reach 90% with purity of 90%.
本工作用JPCIAE事件产生器模拟5.5 TeV/A 208Pb+208Pb对撞产生的7种粒子n、n-、p、p-、K+、π+和光子入射的环境下,对ALICE(A Large Ion Collider Experiment)光子谱仪(PHOS)的光子判别的效率和纯度进行了模拟研究。在簇射形状分析中,采用主成分分析方法将7 参数分析问题约简为2 参数,给出不同能区中的光子判别效率与纯度的关系。
