Walter Selove

The study of CP violation -- the difference in behavior of particles and anti-particles -- will be advanced in a major way by study of certain decays of B mesons. B mesons, and the decays of greatest interest, are difficult to produce in the quantities needed. Several groups in this Department are working intensively at different ways of producing and detecting the large number of B's needed.

The accelerator which offers the highest intensity of B meson production is the hadron-hadron collider. The Tevatron, at Fermilab, currently produces 100 times as many B mesons as the number which will be produced at the Stanford or Japanese electron-positron colliders. To exploit a substantial fraction of this potential intensity, a tracking and trigger system is needed which can process many millions of interactions per second, most of which are uninteresting, and weed out efficiently the few thousand B events per second. In a collaboration with many physicists at other institutions, we have designed a system which appears capable of tracking some 200 million tracks per second, and finding those which have clear secondary decay vertices from beauty quarks (and other heavy quarks). This requires a special purpose pattern-recognition system. Data at the rate of hundreds of gigabits per second is to be transferred on optical fibers to an electronics system which will use some thousands of inexpensive but powerful processors to track all tracks and identify those events with clear and promising secondary vertices. Prototypes of the electronics components are being built at Fermilab, a large group is working at simulating the overall performance of proposed detector designs, and very high speed tracking programs are being developed.

• Guggenheim Fellow (1972-73)
• NSF Senior Postdoctoral Fellow (1956-57)
• Natl. Res. Council Fellow (1946-49)

• Emeritus Professor
• At University of Pennsylvania since 1957
• Instructor, Asst. Professor, Harvard University (1950-56)
• Staff member, Livermore National Laboratory (1953-54)
• Staff member, Argonne Natl. Laboratory (1947-49)
• Staff member, MIT Radiation Laboratory (1943-45)

• "A High-Rate Trigger System for E771," W. Selove, in Proceedings of the Workshop on High Sensitivity Beauty Physics at Fermilab, (A.J. Slaughter et al., Editors), Fermilab, 433-436 (1988).
• "Di-muon and single-muon events from a beauty experiment," W. Selove for the E771 Collaboration, in Proc. of the Meeting of the Div. of Particles and Fields, DPF92, p. 701 ff, World Scientific Pub. Co. (1993).
• "Impact Parameter Trigger and Vertex Detector for Forward Collider Detector," W. Selove, in Proc. of the Workshop on B Physics at Hadron Accelerators (Snowmass, Colorado), 1993, p. 617 ff, Fermilab Report CONF-93/267, P. McBride and C.S. Mishra, editors.
• "Data Transfer and Trigger Processor System for a High-rate Heavy-Quark Collider Detector," W. Selove and K.L. Sterner, Univ. of Pa. Report UPR 227E, Aug. 1, 1994.
• "ON-LINE TRACKING: A simulation package and program development for a collider B detector for the Tevatron," P. Chew, R. Isik, and W. Selove, Univ. of Pa. Report UPR 231E, July 4, 1995.
• "Design of a Secondary Vertex Trigger System for a Hadron Collider," D. Husby, P. Chew, W. Selove, and K.L. Sterner, Nucl. Instr. Meth. A383, (1996), 193.