Nuclear Physics Consolidated Grant

Lead Research Organisation: University of Glasgow
Department Name: School of Physics and Astronomy

Abstract

Approximately 98% of the mass of nucleons, and therefore of the visible universe, emerges from the interactions among their constituents, the quarks and gluons. The Higgs mechanism, which gives mass to the bare quarks, is responsible for only a small fraction of the nucleon mass. The confinement of quarks within mesons and baryons is a direct consequence of their fundamental interactions. The field theory of the strong nuclear force, Quantum Chromodynamics (QCD), is now well established, and yet the phenomena described above cannot be understood from the QCD Lagrangian; they are emergent properties that arise from the unique complexity of these interactions. QCD is as yet intractable at the mass scale of nucleons and nuclei, so a clear picture of the fundamental nature of matter at these energies does not yet exist. However, this situation is set to change, and both theoretical and experimental developments in the coming decade are expected to revolutionise our understanding of nuclear matter within the context of QCD and the Standard Model.

We have an ambitious plan of work that encompasses the development of research programmes from existing themes, possibilities for new physics measurements that have opened up recently, and the completion of physics projects from data that has been previously obtained. Our programme will build on the work of our previous consolidated grant and we will exploit the investment in manpower and equipment to address the current issues in our field at the highest possible level, at the world's top facilities. The challenges for the science programme are encapsulated by several key questions, which we group together as they roughly match the themes we have defined:

* What is the mechanism for confining quarks and gluons in strongly interacting particles (hadrons)?
* What is the structure of the proton and neutron, and how do hadrons get their mass and spin?

* Can we understand the excitation spectra of hadrons from the quark-quark interaction?
* Do exotic hadrons (multiquark states, hybrid mesons and glueballs) exist?

* How do nuclear forces arise from QCD?
* What is the equation of state of nuclear matter?

* What is the nature of dark matter?

We will address these questions by leading experimental programmes at two of the world's leading facilities:

* Jefferson Lab, Newport News, Virginia, USA (JLab)
* MAMI, Mainz, Germany:

Planned Impact

The research themes of the University of Glasgow nuclear physics group aim to improve our fundamental understanding of nucleons and nuclei, which are responsible for most of the visible mass of the Universe, and to provide a detailed understanding of the strong interaction, one of the four fundamental forces of nature, at length scales and energies relevant to our everyday existence. This quest for understanding nature at a very fundamental level - a cultural endeavour in its own right - has over the past decades led to a vast number of practical applications with a large influence on the lives and wellbeing of the entire population.

The understanding of nuclei and their properties led to the development of nuclear power plants and an extensive range of applications in the healthcare sector. Experiments designed and constructed by nuclear physicists are driving the development of radiation detectors, electronic systems and computing algorithms for applications ranging from radionuclide imaging, the monitoring of radioactive waste to security applications. The technologies developed for nuclear physics experiments find widespread applications in nuclear physics research, interdisciplinary research activities and industry. The understanding of nuclear physics itself is important for every citizen wishing to make an informed decision on a variety of issues, from personal healthcare treatments to wider political questions. Modern nuclear physics experiments rely on large scale computing facilities and have developed sophisticated data handling and analysis techniques. These computational techniques find applications in a wide range of problems from economics to medical imaging.

We collaborate with academic and industrial partners, using our expertise and knowledge in a variety of fields, from detector design and construction for the nuclear industry to applications of detectors and accelerators in new forms of cancer treatment. The group's expertise in research and the design, simulation and construction of a variety of detector systems provides a very strong position for knowledge exchange activities, from radionuclide imaging to nuclear monitoring and security applications. Through our work in learned societies, such as the IoP and the EPS, we contribute to the promotion of the field and science in general to the general public.

The academics and researchers of the nuclear physics group play an essential role in training early career researchers in a large variety of technological skills, data analysis and physics interpretation. Graduates of the Nuclear Physics group are employed in a large variety of sectors, from academia to finance, from the NHS to the nuclear industry and national security.

Publications

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