RUI: Symmetry Tests of Standard Model and Beyond via Light Meson Decays

点击翻译按钮获取中文摘要

The goal of this project is to test fundamental symmetries in the electromagnetic and strong interactions. By doing precise measurements of the properties of low-mass neutral mesons at Jefferson Lab, this research aims at understanding Nature by providing clues to some fundamental questions, such as: (1) Why are quarks confined inside of hadrons?; (2) What are the masses of the light quarks?; (3) Why is the observed universe dominant by matter over anti-matter?; and (4) What is dark matter? This project will also offer great opportunities to engage undergraduate students in cutting edge research. It will create a research-enriched learning environment, explore new approaches to recruiting prospective students, and develop new courses that are research-related. The PI will play a leadership role as a spokesperson for the experiments: (1) completing data analysis of a precision measurement of the neutral pion lifetime; (2) optimizing and preparing an approved experiment to measure the radiative decay width of the eta meson; (3) commissioning and operating a new pair spectrometer in Hall D and taking data on eta-meson decay in parallel with the GlueX experiment; and (4) leading the development of the Jefferson Lab "Eta Factory" program. Measurements of various rare and forbidden decays of the eta mesons will provide sensitive probes for possible existence of new forces, which will extend our knowledge to the dark matter and explore new sources of CP violation needed to explain the matter and anti-matter asymmetry in the universe. The discovery of such new forces beyond Standard Model would have far-ranging implications to advance our understanding of nature.