Improvement Of Hadronic Generator LUARLW And Parameters Tuning

The measurement of R-value and the experiment test of QCD theory at BEPC? and BES? need the Monte Carlo generator which can simulate the exclusive process of e+e- to hadrons annihilation.The detection Efficiency is determined by the accuracy of physical model used in MC simulation. The measure of R-value at BEPC?/BES? used the hadron generator LUARLW based on the Lund Area Law and achieved good results.The LUARLW generator only work well in simulation of continuous state and the lowest order hadron process(e+e- ? q0q0 ? string?hadron) and lose effectiveness in the simulation of resonance with JPC= 1--, like e+e- ? J/?,?(3686),?(3773)? ?(4040)??(4160)??(4415)?X(4260)andX(4360). Consequently, the hadron de-tection efficiency determined by the LUARLW at BES? still exist approximately 2% systematic uncertainty.This work improved the BESR? LUARLW generator at BES? and did the parameter tuning on the improved LUARLW by the about 150 energy points distributing in 2.0 - 4.6GeVGeV energy region, it makes the dozens of physics distributions determined by hadron detection efficiency accord with data, and good for reduce the uncertainty of hadron detection efficiency.To make sure the radia-tion correction of narrow resonance be calculated accuracy by generator, the vacuum polarization effect is been disposed.