B.S. 1969 South Dakota State
Ph.D. 1977 Michigan
My area of research is experimental elementary particle physics. My present interest in this field is in experiments which produce particles containing the heavy ``bottom'' or ``beauty'' quark (``bottom-flavored'' particles). I also have a strong interest in the development of semiconductor detectors for use in high-energy physics experiments, and I am currently involved in several major efforts in the continued development of these detectors.
I am currently involved in an electron-positron colliding beam experiment at the Cornell Electron Storage Ring (CESR). This experiment has been collecting data since 1979, and has produced the world's first direct evidence for the existence of ``bottom-flavored'' particles. The experiment uses a large multi-purpose detector called CLEO. It consists of a superconducting solenoid magnet 1 meter in radius surrounded by detector elements which can measure the trajectories of charged and neutral particles. Particles which contain the bottom quark (B mesons) are produced by collisions between electrons and positrons. This process of matter-antimatter annihilation is very useful in producing heavy quark pairs. (Since the ``bottomness'' quantum number is conserved in strong nuclear interactions, the bottom quarks are produced in pairs.) One goal of the experiment is to investigate symmetry (CP) violation by B mesons as a probe of the fundamental nature of the nuclear force. We have recently observed rare decays of the B meson in which such symmetry violations could occur.
I have also worked within the Department's high-energy group on the development of semiconductor pixel detectors for a future experiment called ATLAS. This experiment is under construction at the European particle physics laboratory CERN located in Geneva, Switzerland. It is a multipurpose detector to study collisions between protons. A major goal of ATLAS is to discover the Higgs particle, which is thought to be responsible for the generation of the masses of other particles according to current theory. One possible decay mode of the Higgs particle is to four b quarks so our experience with bottom physics may prove useful in detecting the Higgs. The pixel detectors we are developing will be the detector elements closest to the collision point and will provide the best position measurement for charged particles produced in the collision.
A. Anastassov, P. Skubic, , ``First Observation of the Decay '' , Physical Review Letters 84, 1393 (2000).
J.P.Alexander, P. Skubic, , ``Measurement of decay and |Vub| '', Physical Review D 61, 052001 (2000).