University of the West of Scotland Nuclear Physics Group Consolidated Grant

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Despite more than a century of intense experimental and theoretical research, the nuclear many-body quantum system remains a challenge. In the century that has followed, numerous advances in accelerator and detector technology have firmly established nuclear physics as an international activity at the forefront of scientific research. In the past few decades, the quest to understand the properties of exotic nuclei ever further from the valley of stability has led to considerable experimental progress. The programme of research described in this Consolidated Grant application covers research into the structure and properties of atomic nuclei lying far from stability and collective behaviour in stable nuclei which remains poorly understood. Recent experimental observations, supported by theoretical calculations, have suggested that the structure of exotic nuclei may be different from those near stability. The well-known sequence of magic numbers, corresponding to energy gaps in nuclear shell structure, is now thought to change in nuclei with an extreme excess of neutrons. The evidence for such a change is already convincing around neutron number N=20, and similar effects are expected for the other shell gaps at N=28, 50, and 82. In order to provide a test of nuclear models, experimental data are needed. In this respect, we will focus on the proton-rich nuclei around Sn100 (N=Z=50). An important consideration in the description of an atomic nucleus is its shape. It is well established that nuclei with filled shells of neutrons and protons are spherical, and nuclei with partially-filled shells can become deformed. An exotic form of deformation is when the nucleus takes on a reflection-asymmetric "pear" shape. Such octupole deformation is most prominent in localized regions of the nuclear chart, such as the light actinide region (radium, thorium, uranium nuclei with A~224) and lanthanides near barium-144. In our research programme, we will make a comprehensive study of octupole deformation in nuclei, focusing on the actinide and lanthanide regions, as well as the proton-rich nuclei near N=Z=56. Recent developments in accelerator and detector technology will now allow new types of experiments to be performed to provide new insights into this novel type of deformation. In our research programme, we will make a comprehensive study of octupole correlations in nuclei, focusing on the actinide and lanthanide regions, as well as the proton-rich nuclei near N=Z=56. The mirror-symmetry-violating pear shape allows for the search for physics that is responsible for the existent matter-antimatter symmetry violation. High-powered laser systems are now offering a new method of producing and accelerating particles. Focussing their beams on small areas creates volumes with extreme high energy densities, in which nuclear reactions can happen or from which intense beams of charged particles are emitted. Parts of our research will exploit this novel technical development to explore aspects of nuclear physics which are not possible by conventional means. Our research will performed using varius different experimental techniques. For example, we will carry out Coulomb-excitation experiments at ISOLDE, electron-gamma coincidence spectroscopy and lifetime measurements at JYFL, and laser-induced nuclear reactions at the new ELI-NP facility in Magurele, Romania. The requested funds will provide support for postdoctoral research associates and PhD students to help carry out this work, as well as funds for travel and subsistence. We have also requested funds to enable world leading theoretical nuclear physicists to visit our group to help with the interpretation of our results, and to provide important theoretical input into our experimental research programme.