Study of precise measurements of Higgs in linear collider

1.国际直线对撞机实验的重要目标之一是对Higss粒子的详细研究。由于实验人员的努力，高统计数据，精确的理论计算是强制性的。利用GRACE微扰计算系统计算了高能区Higgs势的全电弱辐射修正。Gμ方案计算的弱修正很小，对于> 600 GeV的能量小于5%。为了证实这一结果，我们对ZHH信道和vμvμHH信道进行了比较，并在假设W W -> HH机制占优势的情况下对弱校正进行了估计.本文介绍了GRACE/SUSY环的重整化方案和特点，GRACE/SUSY环是一个自动计算包含单圈阶次修正的最小超对称标准模型过程的程序包。给出了用GRACE/SUSY环计算的单圈级电荷态的二体和三体衰变宽度.控制大规模计算的数值精度，如GRACE系统自动费曼图计算所产生的数值精度，已成为这些软件包的一个重要组成部分。利用四倍精度和八倍精度的算法库，测试了正负电子对撞机中正负电子τ反τ产生的单圈辐射修正，并给出了丢失位数.我们开发了一个程序，它产生的FORM源的符号操作。这使我们能够有效的内存管理，这对于处理大量的费曼图是必不可少的，因此性能显着提高。

1. One of the most important goals of the International Linear Collider experiments is the detailed study of Higss particle. With the high-statistics data from devoted efforts by experimentalists, precise theoretical calculations are mandatory. We calculated the full electroweak radiative corrections for Higgs potential in the high energy region using the automated system (GRACE) for the perturbative computation. The calculated weak correction in Gμ scheme is small, less than 5% for > 600GeV. In order to confirm the results, we have made the comparison between ZHH channel and vμvμHH channel, and also the estimation of the weak correction by assuming the dominance of W W -> HH mechanism.2. We present the renormalization scheme used in and the characteristic features of GRACE/SUSY-loop, the package of the program for the automatic calculation of the minimal supersymmetric standard model processes including one-loop order corrections. The two-body and three-body decay widths of charginos in one-loop order evaluated by GRACE/SUSY-loop are shown.3. The control of the numerical precision of large-scale computations like those generated by the GRACE system for automatic Feynman diagram calculations has become an instrinsic part of those packages. We tested the 1-loop radiative correction to electron positron tau anti-tau production in electon positron collider, using quadruple and octuple precision arithmetic library where the number of lost-bits is made available.4. We developed the program which generated FORM sources for its symbolic manipulation. This enables us the efficient memory management that is essential for the handling of a tremendous number of Feynman diagrams, so that the performance is significantly improved.