Probing Subatomic Physics Via Lepton Interactions

NSF建议编号0555510TITLE：通过Lepton相互作用探索亚原子物理建议PI：M.Ioana Nrulescu博士、Kevin L.Giovanetti博士、Gabriel Nrulescu博士、James Madison大学詹姆斯·麦迪逊大学粒子和核物理小组由三名教员和一组本科生组成，在杰斐逊实验室(JLab)、费米国家实验室(Fermilab)和保罗·谢勒研究所(PSI)进行中能核物理研究。我们团队的目标是将对研究的重要贡献与为有前途的本科生提供高质量的教育体验相结合。小组成员积极参与JLab的B厅和C厅正在进行的研究(探测器设计和测试、数据获取、数据分析)。该小组也是PSI正在进行的木兰实验(Muon Lifetime实验)和费米实验室Minerva实验(中微子-核相互作用)的关键合作者。这些实验旨在探索核子(质子或中子)的丰富结构，核子是原子核的基本组成部分。人们普遍认为，质子和中子是由三个夸克组成的，这三个夸克被视为基本粒子，通过胶子力聚集在一起。多夸克系统(质子、中子等)的完整图景目前还不能使用。探索核子和原子核结构的研究，如我们小组在JLab和Fermilab参与的研究，希望能澄清这一图景。在四种基本力中，只有弱力才能把一个基本粒子变成另一个基本粒子。最近的理论和技术进步创造了机会，通过以前所未有的精度测量Muon(木兰实验)的寿命，来提高我们对弱力强度的认识。这允许提取费米耦合常数，该常数决定弱力的强度，就像电荷决定电磁力的强度一样。

Abstract for NSF Proposal Number 0555510TITLE: Probing Subatomic Physics via Lepton InteractionsProposal PIs: Dr. M. Ioana Niculescu, Dr. Kevin L. Giovanetti, Dr. Gabriel Niculescu, James Madison UniversityThe James Madison University Particle and Nuclear Physics Group, consisting of three faculty and a group of undergraduate students, conducts research in Intermediate Energy Nuclear Physics at Jefferson Lab (JLab), at Fermi National Lab (Fermilab), and at Paul Scherrer Institute (PSI). The aim of our group is to integrate important contributions to research with a quality educational experience for promising undergraduate students. The group members are actively involved in ongoing research in both Hall B and C at JLab (detector design and testing, data taking, data analysis). The group is also a key collaborator in the MULAN experiment (Muon Lifetime Experiment) underway at PSI and in the Minerva experiment (Neutrino-Nucleus Interactions) at Fermilab. These experiments are designed to explore the rich structure of the nucleons (proton or neutron), which are the basic building blocks of the atomic nucleus. It is widely held that protons and neutrons are built out of three quarks, viewed as fundamental particles, held together by gluonic forces. A complete picture of multi-quark systems (protons, neutrons, etc.) is not yet available. Studies that probe the structure of nucleons and nuclei, such as those in which our group participates at JLab and Fermilab, hope to clarify this picture. Of the four fundamental forces, the weak force is the only one that can change one fundamental particle into another. Recent theoretical and technological advancements have created the opportunity to improve our knowledge of the strength the weak force, by measuring the lifetime of the muon (MULAN experiment) with unprecedented precision. This allows the extraction of the Fermi coupling constant, which determines the strength of the weak force in the same manner as electric charge determines the strength of the electromagnetic force.