The goal of the James Madison University Particle and Nuclear Physics (JMU-PNP) group is to integrate important contributions to top notch research in Intermediate Energy Nuclear Physics with an outstanding educational experience for promising undergraduate students. The three faculty members and their students focus on research designed to explore the structure of nucleons (neutrons and protons) which are the basic building blocks of any atomic nucleus. While it is widely accepted that nucleons are composed of three quarks (viewed as fundamental particles) in constant interaction via gluon exchange, a complete picture of the mechanisms that give rise and govern the evolution of multi-quark systems (protons, neutrons, nuclei) is not yet available. The group participates in studies aimed at clarifying this picture by charting the structure of nuclei and nucleons using electron, muon, and neutrino probes. The group is also involved in measuring the muon lifetime which can be used to extract the Fermi coupling constant which determines the strength of one of the four fundamental forces, the weak force.
Currently the group is actively involved in ongoing research at Jefferson Lab in experimental Halls B and C (detector design and testing, data taking, data analysis), Fermilab (Minerva experiment studying Neutrino-Nucleus Interactions), and Paul Scherrer Institute (measuring the muon lifetime). Additionally, the JMU-PNP group members are key participants in detector development that is part of the 12 GeV energy upgrade at Jefferson Lab and are principal investigators on experiments that will take advantage of this upgrade.
The James Madison University Particle and Nulcear Physics Group, PNP, has been involved in several important actitivities aimed at obtaining a fundamental understanding of particle physics. As an undergraduate institution with considerable emphasis on undergraduate education the PNP group continues to engage and encourage young students in the develoment of technical skills through these activities. The Primary focus has been on the experiments performed at Jefferson laboratory. These experiments probe aspects of both particle and nuclear physics and require continued support from collaborating institutions. Data needs to be carefully recorded, analyzed, and reviewed before publication. Detectors require continued attention including upgrades, calibration, monitoring and evaluation. New elements need to be designed and constructed. There are also some adminstrative roles that are required for proper oversight and collaboration management. The JMU group has been involved across the board by contributing to these various areas. Significant advances have been made towards completing the picture of the workings of particles such as the proton and the neutron. Since these are composite particles built from quarks that are held together by the stong nuclear force (gluonic forces) they are an excellent testing ground for the understanding of quark-gluon physics. In addtion to the nucleon many other more exotic particles that are built from the same constiuents are under study and help to unravel the small scale structure of matter. Building on the successes of the 6 GeV era, a period of experimentation at Jefferson laboratory that relied on the CEBAF electron beam with a maximum energy of 6 GeV, a higher energy 12 GeV upgrade is underway. The possibilities for new experiments are coupled with requirements for detector improvements. The JMU PNP group has been building, testing, and reviewing both new instrumentation as well as prospects for new experiments. The current best model for general particle physics is the Standard Model. It has and continues to be a very succesful model. To test the validty of this theory and to carry out precise calculations using this model a set of measured parameter must be supplied. The μLAN project which has recently succesfully completed, as part of the work done by this group and supported by NSF, a measurement of the Fermi-Coupling constant GF. This result was acheived by completing a precise meansurement of the muon lifetime. The muon is a fundamental particle (similar to an electron but more massive) and as such it has a well understood process by which it decays to an electron and two neutrinos. The experiment acheived a remarkable 1 ppm measurement of the muon lifetime that led to a large improvement ddin our knowleged of GF.
