The outlook for Nuclear Theory Niels Walet School of Physics and Astronomy University of Manchester

“Nuclear theory in the UK is a small but first class effort, with high international visibility...” T H E S E C O N D I N T E R N A T I O N A L R E V I E W 2005

What is Nuclear Theory  Internationally rather broadly defined: The study of the theory of those aspects of (sub)nuclear physics that involve multiple interacting objects…  In UK historically rather narrowly defined (EPSRC Physics!)

Theoretical Nuclear Physics: UK Only two University Groups with full-time NP theorists: Manchester 4 FTE academics [Birse, Bishop, McGovern, Walet] 1+1 PDRA, 1PGR student Nuclear Structures Field Theoretic approaches to many-body systems Effective field theories Quarks and gluons Surrey 4 FTE Academics [Al-Khalili, Oi, Stevenson, Tostevin] 1 Advanced Fellow [Zhao], 1 Emeritus [Johnson] 1+1 PDRA, 13 PGR students Nuclear reactions and dynamics Nuclear dynamics and structure

Others (HEP=Nuclear?)  Edinburgh/Glasgow/Liverpool/....: Lattice QCD  Swansea  Southampton  Manchester Particle Theory  Others? Probably rather thin in nuclear areas?

Interface to Astrophysics Equation(s) of State Nucleosynthesis There is clear theory interest in one (neutron and quark stars). Less theory contribution on second, apart from through standard nuclear experiment support. Not as strong as to PP!

Intenational setting: NUPECC recommends that efforts should be undertaken to strengthen local theory groups in order to guarantee the theory development needed to address the challenging basic issues that exist or may arise from new experimental observations. (NUPECC, 2004) It is imperative to: …. Significantly increase funding for nuclear theory which is essential for developing the full potential of the programme (NSAC 2002)

US effort Theory needs to be reinforced Structure  RIA TG (defunct)  SciDAC-2 collaboration: UNEDF  JUSTIPEN NSAC long range plan 2007 under way; concentrates on facilities, but debates theory: See next couple of slides

Low Energy How do NN and NNN interaction emerge from QCD? How do NNN forces impact structure and reaction properties of nuclei? What are the limits of stability? How does shell structure evolve with neutron number? How do simple symmetries arise in complex system? What is the impact of the continuum on nuclear properties? Can we describe large-amplitude collective motion? What is the microscopic underpinning of emergent phenomena? How do nuclei react with each other? What is the equation of state (EOS) of nuclear and neutron matter? What can nuclei tell us about other systems?

QCD More effort, less specific targets (two white papers) RHIC, LHC, EIC: Theory/models for QCD in nonequilibrium chiral PT Effective field theory lattice QCD Hadron physics phenomenology

European Framework NUPECC Facility for theory: ECTstar in Trento  Will STFC pay UK part? EU Networks (for experiment and theory)!  Low-energy (Structure+reactions)  Hadron Not as coherent for theory as US.

UK effort and future (low energy) Microscopic description of reactions (Surrey) Structure  (effective) few body systems: Surrey  EFT for few body systems: Manchester  Fully microscopic calculations: Manchester  Large Amplitude Collective Motion: Manchester, Surrey  NNN forces: Manchester Can tick many of the US boxes?!

UK effort QCD Plasma  A little in Manchester,  some in other places (HEP) Effective Field Theory  Manchester, Sussex, So'ton Lattice QCD  UK QCD Hadron Phenomenology  Surrey, Oxford, So'ton, Mc/er

Renewal  Much of the existing work seems already well aligned with international goals!  Are we concentrating on strengths?  Must start stronger focus on FAIR physics  NUSTAR  PANDA  Others (CBM)?  Collaboration with lattice QCD  Non-equilibrium QCD/Phase transitions

Conclusions Boundaries with PP theory are fluid Boundaries with Astrophysics important, but theory input mainly on nuclear physics relevant here. Some integration needed But substantial strength in core nuclear physics will help to address key questions Also, we must support FAIR type physics