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Precision Tests of Standard Model at Low Energies with Atoms, Hadrons and Neutrinos

原子、强子和中微子低能标准模型精度测试

基本信息

批准号：
315087841
负责人：
Dr. Mikhail Gorshteyn
金额：
--
依托单位：
Institut für Kernphysik
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2016
资助国家：
德国
起止时间：
2015-12-31 至 2018-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/315087841?language=en
关键词：
Precision Tests Standard Model Low

项目摘要

The Standard Model of elementary particles and fundamental interactions (SM) has been extremely successful in describing and predicting various phenomena in atomic, nuclear and particle physics. Nonetheless this success, there exist numerous indications that physics beyond the Standard Model (BSM) should exist. Precision low-energy tests of SM consists in high-accuracy measurements of SM parameters in the experiments with atoms, nuclei, hadrons and neutrinos. Comparing these measurements to the SM theory predictions one observes or constrains the hypothetical BSM contributions. The precision of modern low-energy experiments probe the BSM contributions due to new particles with masses of 1-10 TeV and are thus comparable or complementary to collider and astrophysical searches. This proposal is dedicated to the extraction of the weak mixing angle from parity-violating electron scattering (PVES) with the Q-Weak and MESA/P2 experiments and parity violation in atoms, extraction of the CKM matrix element V-ud from neutron and nuclear Beta-decay, extraction of neutrino oscillation parameters from short baseline neutrino experiments, extraction of nucleon and nuclear radii from Lamb shift in light muonic atoms and electron scattering, and extraction of properties of Dark Matter particles from direct detection experiments. The common feature of these, otherwise quite different experiments, is the necessity of reliable calculations of SM radiative corrections, in particular, the so-called box graphs that depend on nuclear and hadronic structure and require an inclusion of inclusive nuclear and hadronic intermediate states. At low energy, quantum chromodynamics, the theory of strong interaction, is nonperturbative, and at the moment such contributions cannot be calculated directly from the QCD Lagrangian. To provide box graph calculations at the accuracy level of relevant low-energy precision tests, I propose to use dispersion relations, the method that is based on Lorentz and gauge invariance, unitarity and analyticity. In my previous works I applied this method to Compton scattering with real and virtual photons and to box graph calculations for elastic electron scattering. The scope of this project is the generalization of those studies to the calculation of box diagrams with a photon and a Z(W) and two photons with and without parity violation in arbitrary kinematics, and the generalized Compton process Z(W)+N -> gamma+N underlying the neutrino photon production process. As input to some of dispersion integrals, the electroweak pion production gamma(Z,W)+N -> pi+N amplitudes in a combination with sum rules, effective theories, nuclear effects will be used. This project has a great potential to provide a unified framework for calculating hadronic structure corrections to BSM searches with atoms, electron scattering and beta-decay experiments, neutrino scattering and direct detection Dark Matter experiments.

基本粒子和基本相互作用的标准模型（SM）在描述和预测原子、核和粒子物理中的各种现象方面非常成功。尽管如此，仍有许多迹象表明标准模型（BSM）之外的物理学应该存在。精确的低能SM测试包括在原子，原子核，强子和中微子的实验中SM参数的高精度测量。将这些测量结果与SM理论预测进行比较，可以观察到或约束假设的BSM贡献。现代低能实验的精度探测BSM的贡献，由于新粒子的质量为1-10 TeV，因此可以与对撞机和天体物理搜索相媲美或互补。该方案致力于从Q-Weak和梅萨/P2实验的宇称破坏电子散射（PVES）和原子宇称破坏中提取弱混合角，从中子和核β衰变中提取CKM矩阵元V-ud，从短基线中微子实验中提取中微子振荡参数，从轻μ子原子和电子散射的兰姆位移中提取核子和核半径，以及从直接探测实验中提取暗物质粒子的特性。这些实验的共同特点是必须对SM辐射修正进行可靠的计算，特别是所谓的箱形图，它依赖于核和强子结构，需要包含核和强子的中间态。在低能量下，量子色动力学，即强相互作用理论，是非微扰的，并且目前这种贡献不能直接从QCD拉格朗日量计算出来。为了在相关低能精度测试的精度水平上提供盒图计算，我建议使用色散关系，该方法基于洛伦兹和规范不变性，么正性和解析性。在我以前的工作中，我应用这种方法与真实的和虚拟的光子康普顿散射和弹性电子散射的盒形图计算。该项目的范围是将这些研究推广到计算任意运动学中带有一个光子和一个Z（W）以及带有和不带有宇称破坏的两个光子的箱形图，以及中微子光子产生过程中的广义康普顿过程Z（W）+N -> gamma+N。作为某些色散积分的输入，将结合求和规则、有效理论、核效应使用电弱π介子产生gamma（Z，W）+N -> pi+N振幅。这个项目有很大的潜力，提供一个统一的框架计算强子结构修正BSM搜索与原子，电子散射和β衰变实验，中微子散射和直接检测暗物质实验。