Experimental Nuclear Physics with Electromagnetic Probes

Rensselaer Polytechnic Institute, Troy NY

Investigators

Abstract

The main part of the program focuses on the study of the properties of baryons, i.e. protons and neutrons, and their excitations, using electron and photon beams. The goal is to elucidate the structure of matter in terms of its quark and gluon distributions as determined by quantum chromodynamics (QCD). The program is based at the Thomas Jefferson National Accelerator Facility (JLab). The RPI JLab program has two major aspects. First, to conduct high visibility experiments using the state of the art facilities at JLab. Second, to prepare a physics program and to design and build experimental equipment for the JLab 12 GeV energy upgrade. The planned JLab research for the next proposal period focuses primarily on conducting exclusive experiments at the largest possible momentum transfers, in which all particles produced by the electron beam are reconstructed. These include: 1) the deep virtual Compton scattering (DVCS) and electroproduction of pseudoscalar mesons (DVMP), and 2) the measurement of nucleon excited form factors. Looking toward the future, the group is engaged in preparations for the JLab 12 GeV upgrade. The main long term RPI contribution will continue to be the design, prototyping, and testing of the Hi threshold Cherenkov project (HTCC). From the physics point of view, the RPI group members are leaders of two 12 GeV proposals. One, the measurement of deeply virtual electroproduction of pseudoscalar meson at high momentum transfer has recently been accepted by the JLab PAC as a fundamental component of the 12 GeV physics program. The other, involves the measurement of baryon resonance form factors at high momentum transfer. The program will play a major part in the ongoing JLab program and in the 12 GeV upgrade, which has been specified by the nuclear physics community as one of the highest priority items in nuclear physics. On a broader scale, RPI will continue to produce highly trained PhDs in the physical sciences. Experience shows that these persons typically take on technical career positions in which are important to the US position in technical leadership. The RPI group, typically involves a significant number of undergraduate research participants as a vital part of their technical education at RPI. We will continue to do this.