DEPARTMENT OF PHYSICS & ASTRONOMY

High Energy Particle Physics

HIGH ENERGY PARTICLE PHYSICS - EXPERIMENTAL

Experimental High Energy Particle Physics/Astrophysics

Giovanni Bonvicini, David Cinabro, Mikhail Dubrovin, and Alexander Schreiner

One of the great mysteries in physics is why the fundamental particles come in three and only three families. Studying the properties of the three families in detail is one way to further understand this mystery which is central to understanding the universe at a fundamental level.

The Wayne State CLEO group is focused on investigating the properties of the quarks of the second and third families. CLEO is an experiment at Cornell that currently produces very large samples of the second family charm quark pairs in electron-positron collisions. This is a pristine environment and CLEO is a very capable detector able to see both charged and neutral particles. These allow unmatched sensitivity to rare behavior and unparalleled accuracy in measurements of the charm quark. We are focused on studying charm decays to three bodies and the search for charm quarks spontaneously turning into anti-charm quarks.

We also work on the physics of particle accelerators. When the intense beams of particles collide the electric field of one beam causes the particles of the other beam to radiate. This radiation can be measured to learn if the beams are colliding head on or not. Properties of the radiation also indicate exactly how the beams are missing each other and allow them to quickly be brought back into proper alignment. A prototype is in the electron-positron ring at Cornell and we are developing the detector for use in a future high-energy electron-positron linear collider.

Our research is supported by the National Science Foundation of the United States.

For more information on CLEO see http://w4.lns.cornell.edu/public/CLEO/ .

Experimental High Energy Particle Physics and Detectors

Robert Harr, Paul Karchin and Mark Mattson

The energy of the universe consists mainly of dark matter and dark energy. Little is known about the nature of either, but one or both may turn out to be sub-atomic particles. These particles may be produced in high energy particle collisions or they may affect the decay properties of established particles. Both methods are being pursued using the Collider Detector at Fermilab (CDF), located near Chicago. We study collisions of 980 GeV protons with anti-protons (p-bars) of the same energy, but opposite direction. The Fermilab Tevatron accelerator, which produces these collisions, is the highest energy particle accelerator in the world.

The CDF can identify new, large mass particles produced in the pbar-p collisions. For example, the elusive Higgs boson is predicted to have a mass of about 120 times the mass of the proton. Another class of large mass particles which has been hypothesized are the supersymmetric particles, some of which may be types of dark matter.

Particles containing the charm quark are produced copiously in the pbar-p collisions at Fermilab. The Wayne State group is studying rare decays of charm particles for evidence that the decays are affected by the existence of previously undiscovered, high mass particles.

The Wayne State group maintains operation of the front-end electronics for the CDF calorimeters. The calorimeters are a key part of the CDF apparatus and are used to measure the energy of pions (and other strongly interacting particles) as well as electrons.

A new accelerator is under development by the world-wide physics community: a high energy electron-positron linear collider. This accelerator could make precise measurements of the properties of new, high mass particles. The detector for the collisions produced by the linear collider will require novel technologies. At Wayne State, we are developing a prototype muon detector which could meet the requirements for accurate time resolution, good spatial granularity and stable long term operation.

Our research is supported by the United States Department of Energy.

For information about the CDF experiment, see http://www-cdf.fnal.gov/pubcdf.html.
For information about the Linear Collider, see http://blueox.uoregon.edu/~lc/alcpg/

Recent Publications:

D. Acosta et al. (CDF Collaboration), ``Search for the Flavor-Changing
Neutral Current Decay D0 -> mu+ mu- in p-pbar Collisions at sqrt(s) =1.96 TeV'', Phys. Rev. D68, 091101 (2003).

D. Acosta et al., (CDF Collaboration), ``Observation of the Narrow State X(3872) -> J/psi pi+ pi- in p-pbar Collisions at sqrt(s) = 1.96
TeV", to appear in Phys. Rev. Lett. (2004).

HIGH ENERGY NUCLEAR & PARTICLE PHYSICS -THEORETCIAL

High Energy Nuclear & Particle Theory

A. Petrov, W. Rolnick, F. Gabbiani, and J. Tandean

The aim of theoretical high energy physics is to seek and understand the universal laws of Nature. The major thrust of research pursued by the Wayne State University particle theory group lead by Prof. Alexey Petrov is the issues pertaining to the understanding of the structure of the fundamental electroweak Lagrangian at the smallest scales and development of the theoretical tools needed for “clean” interpretation of the experiments designed to answer such fundamental questions as the origins of mass and CP-violation.

Given the complicated dynamics of strong interactions, the interpretation of experimental observables in terms of fundamental parameters is often complicated, which makes the study of the strong interaction effects absolutely crucial. In this regard, the promise of heavy quark states is that these effects can be studied systematically by exploiting symmetries arising in the limit of infinite mass of the heavy quark. The existence of the large scale associated with the mass of the heavy quark also allows for development of efficient and controllable approximations leading to significant reduction of theoretical uncertainties. The underlying theme behind all aspects of the group’s work is the application of quantum field theory to the problems of particle phenomenology. In recent years the group has worked on a variety of problems in the theory and phenomenology of the strong, electromagnetic, and weak interactions. A partial list of research topics includes studies of the properties of heavy hadrons, applications of effective field theories to problems in Quantum Chromodynamics (QCD), meson spectroscopy, and physics of CP-violation. The group is also one of the leaders world wide in the description of weak transitions of charmed hadrons. The research program of WSU’s particle theory group has significant overlap with current research interests of the Wayne State experimental particle physics groups.

These activities are supported by grants from the U.S. National Science Foundation and Department of Energy.
For more information see http://www.physics.wayne.edu/~apetrov/particle_nuclear/