Grant: Subatomic Physics Envelope - Project

The nucleus at the center of atoms of all known chemical elements in the universe consists of protons and neutrons, which in turn are made up of quarks. The interaction of these constituents is responsible for the stability and structure of the atom, and with that for the resulting abundances of the elements and their isotopes in the universe and on Earth. Information on the stability of atoms can be gained by carrying out precision experiments, such as mass measurements and decay spectroscopy. The mass of an atom and from there the deduced binding energy reflects all subatomic interactions, making it possible to identify how the interaction behaves as a function of neutron and proton number and their combination. Since the advent of rare-beam facilities and dedicated accelerator complexes, the access has been possible to about 3500 isotopes. One of the leading facilities for the production of these rare isotope beams (RIBs) is ISAC (Isotope Separator and Accelerator) at TRIUMF. The availability of more exotic RIBs, with very asymmetric neutron-to-proton ratios, makes it possible to study in much detail the effects of the interaction of the nucleons. Theoretical approaches are building on the very successful Shell Model and are extending to account for phenomena observed in very exotic nuclei. Moreover, other theoretical approaches make use of significant progress in Quantum Chromo Dynamics (QCD) to describe the nuclear interaction from first principles. There is enormous progress in the theoretical field, and the experiments carried out within this proposal aim at studying detailed predictions from these theories. TITAN is involved in providing high precision measurements for super-allowed beta decay and has a program to investigate nuclear structure and the evolution of magic numbers and 3-body effects. Nuclear Astrophysics and the quest to understand the evolution of the chemical elements in the Universe requires deeper understanding of nuclear physics, which can be gained with precision measurements. All scientific quests described here are possible because of the well-established and leading edge performance of the TITAN facility in combination with availability of the relevant isotopes in unprecedented and competitive quantities and quality at the ISAC on-line facility at TRIUMF. In the very near future ARIEL (Advanced Rare IsotopE Laboratory), will be able to almost triple the available experimental opportunities, and provide novel isotope beams. This world-wide unique installation provides for exceptional experimental opportunities for mass measurements and in-trap decay spectroscopy, making use of significant investments in the facility and development of skills and technology of TITAN.