Theoretical Physics
The research interests of the theoretical physics group at SLAC cover virtually
all areas of high-energy physics, from the development
of fundamental theories and concepts, to detailed tests of these theories
at high-energy colliders, B factories, and other experimental facilities.
The predictions of electroweak theories within and beyond the Standard
Model, including the properties and experimental signatures of the Z and
W vector bosons, the Higgs boson, and the top quark, are of particular
interest. Members of the group are also involved in the study and devel-opment
of fundamental theories unifying particle physics with gravity, such as
string theory. One set of questions being pursued by the theory group involves
the phenomenological effects of supersymmetry and other theories beyond
the present Standard Model. There is considerable work focused on investigating
possible origins and signatures of CP violation, which will be experimentally
tested at PEP-II, the high-luminosity B factory now under construction
at SLAC. Also in progress are studies of quantum chromodynamics (QCD)
and the quark and gluon structure of hadrons in exclusive and inclusive
processes using heavy quark reactions such as B-meson decays, hadronic
spin phenomena, nuclear effects, and the properties of particle and jet
distributions in high-energy collisions. Hadronic reaction mechanisms such
as diffractive and rapidity gap phenomena are also being examined.
In addition to these phenomenological studies, the theory group is working
on the basic theoretical problem of combining the gauge interactions of
particle physics with gravity. In this direction, duality symmetries and
nonperturbative physics in string theory are being investigated, particularly
in relation to supersymmetry breaking and the stability of non-supersymmetric
string backgrounds. Also of interest are black holes and other aspects
and approaches to quantum gravity. One fascinating piece of data that must
be addressed by any such theory is the vanishing (or near vanishing) of
the cosmological con-stant relative to the scales that are present in particle
physics.
Additional research topics include: the phenomenology of electron- positron
and photon-photon collisions at TeV energies, the fundamental theory of
collider interactions, adapting methods used for superstrings to the computation
of high-order perturbative gauge theory amplitudes in QCD, nonperturbative
light-cone Hamiltonian and wavefunction methods, few-body problems, fundamental
quantum measurement theory, unified field theories, and numerical simulation
methods for a variety of theoretical and experimental physics problems.
The very close and rather unique collabora-tion between the experi-mental
and the theoreti-cal efforts at SLAC provides an exciting and stimulating
atmosphere for graduate study.
SLAC