Collinear and Soft Gluon Corrections in Top Quark and Higgs Processes at the LHC and the Tevatron

“该奖项是根据2009年美国复苏和再投资法案（公法111-5）资助的。“理解和控制QCD的影响对于执行标准模型（SM）的精确测试以及在强子对撞机上检测和识别新物理的信号至关重要。微扰QCD计算受到重正化和因子化标度依赖的困扰，导致在强耦合常数的微扰序列中，在首阶处的典型O（100%）截面的预测中的不确定性。为了减少对这些任意的非物理参数的依赖，QCD预测需要包括更高阶的修正。在这个提议中考虑的SM过程的截面都是已知的次领先阶（NLO）QCD（顶部对生产，单顶部生产）和次领先阶（NNLO）QCD（希格斯通过胶子聚变生产）。 PI打算通过包括软胶子再活化来进一步改进这些计算。建议的计算将进一步减少剩余的理论不确定性，由于规模的依赖性，这是必要的，在设想的实验精度在大型强子对撞机。在数据分析中，多用途蒙特卡罗（MC）生成器，如Pythia和Herwig是常用的工具，但提供改进的预测，包括高阶修正超越部分子簇射的方法，在MC工具的形式仍在进行中。更广泛的影响如下：拟议的活动将发挥重要作用，在SM及其超对称扩展中提供各种过程的改进QCD预测，这对充分利用LHC的物理潜力至关重要。此外，作为该项目的一部分开发的微扰QCD的计算进步以及Herwig++中包含的软重构将有利于强子对撞机现象学的整个领域。他计划通过为肯尼索的教学硕士课程的未来教师提供粒子物理学的研究经验来扩展这些活动。

"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."Understanding and controlling the effects of QCD is crucial for performing precision tests of the standard model (SM) and detecting and identifying signals of new physics at hadron colliders. Perturbative QCD calculations are plagued by the dependence on the renormalization and factorization scales, resulting in uncertainties in the predictions of cross sections of typically O (100%) at leading order in the perturbation series in the strong coupling constant. To reduce the dependence on these arbitrary, unphysical parameters, QCD predictions need to include higher order corrections. The cross sections of the SM processes under consideration in this proposal are all known at next-to leading order (NLO) QCD (top-pair production, single top production) and next-to-next-to leading order (NNLO) QCD (Higgs production via gluon fusion). The PIs intend to further improve these calculations by including soft gluon resummation. The proposed calculations will further reduce the residual theoretical uncertainties due to the scale dependence, which is necessary in view of the envisioned experimental accuracy at the LHC. In the data analysis multi-purpose Monte Carlo (MC) generators such as Pythia and Herwig are well-used tools but providing improved predictions including higher-order corrections beyond the parton shower approach in form of a MC tool is still work in progress. The broader impacts are as follows: The proposed activities will play an important role in providing improved QCD predictions of a variety of processes in the SM and its supersymmetric extension that are crucial to fully exploit the physics potential of the LHC. Moreover, the calculational advancements in perturbative QCD developed as part of this project as well as the inclusion of soft resummation in Herwig++ will benefit the entire field of hadron collider phenomenology Dr. Kidonakis is already involving undergraduate students in his research activities. He plans to extend these activities by providing future teachers of Kennesaw's Master of Arts in Teaching program with a research experience in particle physics.