Studies of shell evolution using transfer reactions at ISOLDE

Neutrinoless double beta decay is a currently unobserved process, but has wide implications for many fields in physics if the process is discovered. It would help to determine the absolute masses of each neutrino, and would be an example of the violation of lepton number conservation. An aspect of this process is determining viable nuclei for observing this process. The student will look at single-particle transfer reactions to characterise the cross-sections and occupancies for particular candidate nuclei. These results will then be compared to a number of theoretical calculations of nuclear matrix elements for validation. This will then extend further to using a radioactive beam to identify further candidates. This will make up the first part of the project.

The next part of the project will follow onto examining the change in shell structure of isotopes. The spin-orbit interaction shed light on why shell gaps occur, and predicted the correct "magic numbers" for shell closures. However, single-particle state stability is poor, as these magic numbers will change far from the line of stability. Exploring this change in the fundamental structure of the atomic nucleus will help discover and explain new physics phenomena. To that end, transfer reactions will be used at ISOLDE to measure the occupation energies of single-particle orbits to track the evolution of the underlying shell structure. This may move on to using stable targets and radioactive beams to track the structure away from the line of stability.