Coordination Funds

协调基金

• 批准号: 498960258
• 负责人: Professor Dr. Achim Denig
• 金额: --
• 依托单位: Deutsches Elektronen-Synchrotron (DESY), Standort Zeuthen
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/498960258?language=en
• 关键词: Coordination; Funds

Photon-photon interactions play a central role in the Standard Model (SM) of particle physics. It is fascinating to realize that these gamma-gamma interactions, and, in particular, the light-by-light (LbL) scattering, are effects of purely quantum origin. A precise calculation of these effects in the SM is, however, not always straightforward - major obstacles are posed by the non-perturbative nature of the strong interaction, described by quantum chromodynamics (QCD). The Research Unit (RU) intends to overcome these obstacles with important consequences for various aspects of SM physics. The team of researchers of the RU has broad and complementary expertise in various aspects of photon-photon physics, both in theory and experiment. By including international experts, this RU will expand its expertise and advance the understanding of photon-photon interactions as a precision and discovery tool, and thereby have a decisive impact on hadron and particle physics. More specifically, the RU will perform: - the world’s best determination of meson transition form factors (Project TFF). Measurements at the BESIII experiment in Beijing will be complemented by determinations from Dalitz decays at A2-MAMI in Mainz as well as dispersive studies in phenomenology and lattice QCD calculations.- partial wave analyses of exotic mesons in the charmonium sector (Project XYZ). This will be achieved through a collaborative effort between the BESIII collaboration and theorists within the RU and will allow to determine the nature of these exotic states of hadronic matter.- measurements at the ATLAS experiment at the LHC and theoretical interpretations of the direct light-by-light reaction gamma-gamma into gamma-gamma (Project LBL). - world-class searches for axion-like particles in the MeV to TeV mass range (Project ALP). These searches will be carried out in very different physics environments at BESIII, ATLAS, A2-MAMI, and - at a later stage - at the new MESA facility in Mainz.As can be seen from these issues, photon-photon physics may hold the key to new discoveries, whether these are new exotic mesons, ALPs, or precision effects beyond the SM. The most important and pressing of these SM tests is the relation of photon-photon physics to the anomalous magnetic moment of the muon, for which very recently a deviation on the level of 4.2 standard deviations between the SM prediction and its direct measurement has been observed. By a joint effort of experiment, dispersive analyses and lattice QCD calculations (Joint Research Project, JRP), we will constrain the HLbL contribution to the anomalous light-by-light contribution with the precision level targeted by the future precision of the Fermilab (US) and JPARC (Japan) experiments.

光子-光子相互作用在粒子物理学的标准模型（SM）中起着核心作用。令人着迷的是，这些伽马-伽马相互作用，特别是光-光（LbL）散射，是纯粹量子起源的效应。然而，在SM中对这些效应的精确计算并不总是那么简单--主要的障碍是由量子色动力学（QCD）描述的强相互作用的非微扰性质造成的。研究单位（RU）打算克服这些障碍与SM物理学的各个方面的重要后果。RU的研究人员团队在光子-光子物理学的各个方面，无论是理论还是实验，都具有广泛的互补专业知识。 通过包括国际专家，该RU将扩大其专业知识，并推进对光子-光子相互作用作为精确和发现工具的理解，从而对强子和粒子物理学产生决定性影响。更具体地说，RU将执行：-世界上最好的介子跃迁形状因子测定（TFF项目）。北京BESIII实验的测量将得到美因茨A2-MAMI Dalitz衰变的测定以及唯象学和晶格QCD计算中的色散研究的补充。charmonium部门中奇异介子的分波分析（XYZ项目）。这将通过BESIII合作和RU内的理论家之间的合作努力来实现，并将允许确定这些强子物质的奇异状态的性质。在大型强子对撞机的ATLAS实验测量和直接光-光反应伽马-伽马到伽马-伽马的理论解释（LBL项目）。- 在MeV到TeV质量范围内寻找轴子状粒子的世界级搜索（ALP项目）。这些研究将在BESIII、ATLAS、A2-MAMI以及稍后在美因茨的新梅萨设施的非常不同的物理环境中进行。从这些问题中可以看出，光子-光子物理学可能是新发现的关键，无论这些发现是新的奇异介子、ALP还是超越SM的精确效应。这些SM测试中最重要和最紧迫的是光子-光子物理学与μ子异常磁矩的关系，最近已经观察到SM预测与其直接测量之间的4.2标准偏差。通过实验，色散分析和晶格QCD计算（联合研究项目，JRP）的共同努力，我们将限制HLbL的贡献，以反常的光的光的贡献与精度水平的费米实验室（美国）和JPARC（日本）的未来精度的目标实验。