Documents for this Research Project
Basic Information of this Research Project（Latest year）
Project Year
FY1996〜FY1998
Research Field
Screaning Classification
一般
Research Category
基盤研究(C)
Research Institution
明治学院大学
Budget Amount
- Total：¥1900000
- FY1996：¥800000 (Direct：¥800000)
- FY1997：¥500000 (Direct：¥500000)
- FY1998：¥600000 (Direct：¥600000)
Abstract(Latest report)
本研究では,超対称性理論によって予言される様々な新粒子の相互作用を自動計算するシステムの開発と,それを使った超対称性理論の現象論の研究を行った.高エネルギ-加速器研究機構の南建屋グル-プが開発したファインマン振幅の自動計算システムGRACEに,超対称性理論のうち最も基本的な最小超対称標準モデルの相互作用を組み込み,最低次のオ-ダ-の超対称性粒子生成反応の自動計算を可能にした.その際,フェルミオン数を保存しない相互作用頂点をGRACEで自動的に扱うための理論的問題を解決した.
ついで,on-shell renormalization schemeに基づいて,このモデルの繰り込み理論を確立した.紫外部の発散の正規化には,dimentional reductionと呼ばれる新しい技術を使った.カウンタ-項相互作用をGRACEに組み込んで,超対称性理論に基づいて各反応を,一ル-プのオ-ダ-の輻射補正を含めて自動的に評価する事ができるようになった.
この新しいGRACEを使って,H+→tbの崩壊幅,電子陽電子反応によるWボゾン対生成反応における超対称性粒子の効果,荷電ヒッグス粒子対生成における輻射補正の大きさ等を調べている.
自動計算システムGRACEのチェックが終わり,システムが安定すれば,超対称性理論で予言されているさまざまな反応が自動的に計算できるようになる.
The aim of this research is to construct the system of automatic computation of the Feynman amplitudes of the processes in the framework of supersymmetric theories (SUSY) and evaluate the radiative corrections to the SUSY processes. Among the SUSY thoeries, we have adopted the
minimal supersymmetric extension of the standard model (MSSM) which is the smallest but most basic model of SUSY.
By adding to the GRACE, which is the system of the automatic computation of the standard model (SM) constructed by KEK minami-tateya group, a new model file which deals with the MSSM interations, we have upgraded GRACE.Using the upgraded GRACE we have computed several SUSY particle pair production processes and constructed the generator of such processes.
In the next stage of the project, we have established the on-shell renormalization scheme for the MSSM and coded the counterterm lagrangian. The GRACE system was modified so that the ultraviolet divergence is regularized by the dimensional reduction method.
Using the system so constructed, we have computed the decay process H^+* tb in the one-loop order, which serves also for the checking of the GRACE system, upon comparing the GRACE result with the (partial) theoretical computations made in the past. We are investigating other proesses such as SUSY contribution to e^+e^-*W^+W^-. Once it is confirmed that the system is working properly, we are able to compute any MSSM process up to the one-loop order.
URI of this page
http://kaken.nii.ac.jp/en/p/08640391