Modern nuclear physics seeks to understand the structure of all hadronic matter. Studies of the structure of atomic nuclei now explore new regions of excitation, angular momenta, and stability that have only become accessible to detailed study through the advent of more advanced detector arrays and radioactive ion beams. The understanding of the structure of light nuclei has advanced both through modern computational techniques and effective field theories using the nucleon-nucleon force, and through intermediate energy photon and electron experiments that have illuminated the role played by mesons, baryon resonances, and the quark substructure of the nucleon in the nucleus. The baryons and mesons themselves are studied experimentally over a wide energy range with photon, neutrino, electron, meson, and proton beams, and are studied theoretically with Quantum ChromoDynamics computations, using Chiral Perturbation Theory, Lattice QCD, and perturbative QCD. Fundamental symmetries are probed in a variety of experiments, such as parity violating electron scattering from quarks in the nucleon. Indeed, modern nuclear physics now encompasses areas of research which had been considered the domain of particle physics. Our experimental nuclear physics group studies a range of these topics, with two faculty members in nuclear structure and two in intermediate energy.
The low-energy experimentalists probe nuclear structure far from stability, and In systems that exhibit unique properties by measuring electromagnetic moments, level energies, single-particle strengths and gamma-ray transitions using a variety of nuclear probes. They work closely with theorists to understand the structure of nuclei as well as nuclear reaction mechanisms, and the coupling between the two in weakly bound nuclei. This group has also been noted for their broad range of interests, many of which are only peripherally related to standard nuclear physics, but could more appropriately appear under the atomic physics, condensed-matter, nuclear astrophysics or stewardship science headings.
The two intermediate energy physicists, with a long history of work with hadron probes, now concentrate on experiments using photon, neutrino, and electron beams. These experiments try to determine basic properties of the nucleon and few-body systems, and to investigate how the nuclear environment affects the nucleon. Many of the experiments involve polarized electron beams and measurements of the polarization of recoil protons, a field in which they are world leaders.
Major low-energy nuclear
physics efforts are conducted at accelerator laboratories at
Professor Jolie Cizewski
I am interested in studying and understanding the structure
of atomic nuclei, and in particular, nuclei with many more neutrons than stable
isotopes. Theoretical models predict that the shell structure that
characterizes stable nuclei may be quenched in very neutron-rich nuclei. Some
of these neutron-rich nuclei also lie along the path of species most likely to
be populated in the rapid neutron capture process of nucleosynthesis. The
studies of the properties of unstable nuclei are performed at the Holifield
Radioactive Ion Beam Facility at Oak Ridge National Laboratory in
Professors Ronald Gilman and Ronald Ransome
Our research program for the past several years has focused on the structure
of the nucleon and light nuclei, and on what happens to a nucleon in the
nuclear environment. We began the new era of physics at Jefferson Lab by
building on our recognized expertise in spin physics to construct the world's
largest focal plane polarimeter (FPP), along with our colleagues at William
& Mary. The FPP, sited at
In addition to this rich program centered at Jefferson Lab, we have embarked on a major new experimental effort in neutrino scattering at Fermilab. The NuMI intense neutrino beam was commissioned in 2004 at Fermilab, opening the way to a new generation of neutrino experiments. We are founding members of the Main INjector Experiment Neutrino-A experiment MINERνA. This experiment uses a compact, fully active scintillator detector to make high precision neutrino scattering measurements. Our group has been responsible for construction of major elements of the detector and software development. The detector was completed in early 2010 but data taking began with the partially complete detector in late 2009. Data taking is anticipated to continue through at least 2016.
Our involvement in the Fermilab SEAQUEST experiment is an outgrowth of our nucleon structure work at Jefferson Lab. The experiment uses the Drell-Yan process, in which a beam quark and target anti-quark annihilate into a μ+μ- pair, to measure nucleon sea quark distributions. The use of nuclear targets allows access to other physics, such as quark propagation in nuclear matter and the EMC effect. For this experiment, we have been responsible for some of the particle tracking detectors, as well as parts of the data acquisition and trigger systems. The run is planned for 2010-2012, but discussions are ongoing about follow up experiments involing polarized targets, meson beams, and measurements at the new JPARC facility in Japan.
Professor Noémie Koller
The electromagnetic properties of low-lying nuclear states are very
sensitive indicators of the underlying nuclear structure, and in particular, of
the interplay between single particle and collective excitations which have
been found to coexist even at very low energies. We carry out experiments
designed to measure the magnetic dipole and electric quadrupole moments of very
short lived, high spin, nuclear states, and of exotic nuclei
far-from-stability. Radioactive beam facilities are being planned in the
Revised June, 2010