Theoretical Physics

Academic Staff

Dr Alex Love
Reader in Particle Physics

Dr Mike Wilson
Lecturer in Physics

Research Officers

Dr Wafic Sabra (PPARC)

Collaborators

Professor David Bailin
University of Sussex

Dr Steven Thomas
QMW

Tel: +44 (0)1784 443505
Fax: +44 (0)1784 472794
E-mail: m.wilson@rhbnc.ac.uk

Personnel

Dr Love took his degrees at Glasgow Uniersity and worked at the Rutherford Laboratory and Sussex University. He specialises in particle theory.

Dr Wilson was educated at Imperial College, London and then worked at Argonne National Laboratory (University of Chicago), Johns Hopkins University and the University of Reading. He specialises in fundamental atomic theory and its application to laboratory and astrophysical plasmas.

Particle Theory

The main area of interest is the derivation of properties of low energy supergravity that may have a bearing on particle physics at accelerator energies from compactifications of heterotic string theories. Heterotic string theories begin with 10 dimensions for the right moving degrees of freedom and 26 dimensions for the left moving degrees of freedom. Various constructions of a four-dimensional theory exist which may describe the world in which we live, eg orbifold compactification, free fermion construction, compactification on Calabi-Yau manifolds and tensoring of representations of the superconformal algebra. Of these, orbifold compactification, ie compactification on a torus with points identified by a discrete group, is perhaps the best developed. In the low energy limit (compared to the string scale) the string theory reduces to an effective N = 1 supergravity theory and it is possible in principle to derive information from the string theory concerning parameters which would otherwise be free parameters of the supergravity theory. In this way it is possible to obtain information relevant to Yukawa couplings, Kahler potentials and gauge coupling constants. Such information is needed if we are to be able to calculate quark and lepton masses, to understand unification of gauge coupling constants at 1016 GeV, and to derive the properties of supersymmetry breaking in low energy supergravity.

The general direction of research in the medium term will continue to be the derivation of properties of low energy supergravity from string theory.

Research Grants

Superstrings and Low Energy Supergravity (PPARC).

Low Energy Manifestations of String Theory (PPARC).

Atomic Theory

The Cray ymp supercomputer at RAL is used to calculate, from first principles, atomic wavefunctions; these are then used to calculate level structures and transition rates of different processes (such as autoionization) used for a variety of applications in high and low temperature laboratory and astrophysical plasmas. These range from X-ray lasers to the physics of solar flares and stellar atmospheres at temperatures of many millions of degrees down to ion traps which allow study of the quantum fluctuations of a just a single ion or small cluster of ions maintained at temperatures as low as a few thousandths of a degree absolute. Fundamental work on the ab initio calculation of quantum mechanical phases and amplitudes of (e,2e) processes is currently being explored.

Research Grants

The research is funded by the UK Research Council (PPARC), the European Union (EU) and NATO. Current research grants are:

Atomic Structure Calculations in Astrophysics (PPARC).

Structure and Dynamics of Atoms and Ions by Inner-Shell Excitation (EU).

Ionization and Coincidence Spectroscopies (EU).

UK Collaborations

The Solar Physics Group of the Daresbury and Rutherford Appleton Laboratory (DRAL), University of Southampton.

European Networks

Structure and Dynamics of Atoms and Ions by Inner-Shell Excitation: with Mathematics Dept and 16 other groups in Europe.

Ionization and Coincidence Spectroscopies: with Mathematics Dept and 16 other groups in Europe.

International Collaborations

University of Caen, Technical University Berlin, Los Alamos, University of Kentucky, Kansas State University.

The Royal Society has funded exchange visits with the Institute of Theoretical Physics and Astronomy, Vilnius.

The British Council has funded research visits with the Technical University, Poznan.

NATO has funded exchange visits with Kansas State and Illinois State Universities.

Selected Recent Publications

String unification and extra matter multiplets below the string scale
D Bailin and A Love
Phys Letts B280 26-30 (1992)

Kahler potentials for twisted sectors
of ZN orbifolds
D Bailin and A Love
Phys Letts B288 263-268 (1992)

String unification, grand unification and string loop threshold corrections
D Bailin and A Love
Phys Letts B292 315-320 (1992)

Twisted sector Yukawa couplings for the ZM x ZN orbifolds
D Bailin, A Love and W A Sabra
Nucl Phys B403 265-290 (1993)

Duality symmetries in orbifold models
D Bailin, A Love, W A Sabra and S Thomas
Phys Letts B320 21-28 (1994)

Isotope shifts for the 5d56s 7s and 5d56s6d configurations of Re I
H-D Kronfeldt, D Ashkenasi, G Basar,
L Neale and M Wilson
Zeit f Physik D: Atoms, Molecules and Clusters 25 185-189 (1993)

Interpretation of the odd parity levels of Pb I
J Dembczynski, E Stachowska, M Wilson,
P Buch and W Ertmer
Phys Rev A49 (2) 745-754 (1994)

Helium-like argon line emission in solar flares
K J H Phillips, L K Harra, F P Keenan,
D M Zarro and M Wilson
Astrophysical Journal 419 426-431
(1993)

Determination of complex ionization amplitudes by (e,2e) spectroscopy
N L S Martin, D B Thompson, R P Bauman and M Wilson
Phys Rev Letters 72 2163-2166 (1994)

Study of photon spectra emitted during N5+ - Li collisions
G Rieger, P Boduch, M Chantepie,
G Cremer, E Jacquet, D Lecler and
M Wilson
Physica Scripta 50 493-500 (1994)

Photoelectron spectra in cadmium: comparison with theory and (e,2e) spectra
N L S Martin, D B Thompson, R P Bauman and M Wilson, J Jiménez-Mier,
C D Caldwell and M O Krause
J Phys B: At Mol Opt Phys 27 3945-3951 (1994)

Investigation of complex ionization amplitudes in cadmium by (e,2e) spectroscopy
N L S Martin, D B Thompson, P R Bauman and M Wilson
Phys Rev A50(5) 3878-3885 (1994)