Department of Physics and Center for Computational Science
Based on research by:
G.F. Bonini, C. Rebbi Boston University
S. Habib, E. Mottola, LANL
R.Singleton, Jr. University of Washington
P.Tinyakov INR, Moscow
The states of the electroweak theory are characterized by a topological number. Processes which change topology give origin to baryon number violation.
The animations below illustrate the semiclassical description of a collision process. The flux of incoming particles is represented by the imploding wave, the outgoing particles by the exploding wave. The phase of the complex field is color coded. A rainbow pattern indicates that the phase winds around the unit circle and that the state has non-trivial topology.
Sequence 1: Collision with an energy barely above the sphaleron barrier (E_sph) which separates states of different topology. The topology changes.
Sequence 2: Collision with energy larger than E_sph . No change of topology.
Sequence 3: Collision with E > E_sph. Topology change and reduced incoming particle number.
Sequence 4: Collision with energy below the sphaleron barrier. No change of topology.
Sequence 5: Collision with E < E_sph . The evolution is continued along the imaginary time axis. Change of topology occurs through tunneling.
Hardware: SGI Power Challenge Array and SGI Origin2000.
Software: Fortran 77, MPI. Visualization done using IRIS Performer.
Graphics programming assistance and video production: Erik Brisson and Kathleen Curry, Scientific Computing and Visualization Group, Boston University.
Acknowledgments: Research supported by the U.S. Department of Energy