Raymond E. Frey

Physics Department
1274 University of Oregon
Eugene, OR 97403-1274

541-346-5873 (phone)
541-346-5217 (fax)
rayfrey@uoregon.edu
 current CV  (pdf format)

Ray Frey


Research in "Fundamental Physics" of Elementary Particles and Gravitational Waves


Search for Gravitational Waves and GW Astronomy: LIGO

The possibility of opening a new window on the universe with gravitational waves has led to the LIGO project. Gravitational waves were predicted by Einstein's General Theory of Relativity and have not yet been directly observed. Such an observation is the first goal of LIGO. LIGO consists of two observatories, one in Washington state and one in Louisiana. The UO LIGO group mostly works at the Hanford observatory and on data analysis on campus.  LIGO took data for about two years, starting 11/2005,  at design sensitivity. At this sensitivity, LIGO could detect the merger of a binary neutron-star system at the distance of the Virgo cluster of galaxies (15-20 Mpc). LIGO is currently transitioning from initial LIGO to Advanced LIGO (aLIGO). aLIGO will have sensitivity 10x better than the intial detectors (corresponding to 1000x bigger search volume). Data taking with aLIGO is expected to begin in 2015.
Some introductory papers/documents about LIGO: LIGO journal publications.

The UO-LIGO group presently (2012) consists of :


Probing New Physics at the TeraScale I: The Atlas experiment at the  of the CERN Large Hadron Collider

The Atlas exeperiment at the CERN LHC will begin initial running late in 2007 as a tune-up for its running at a new record energy of 14 TeV center of mass energy, where it will be sensitive to many possible new phenomena predicted to occur at the TeV energy scale. The Oregon HEPex group joined Atlas in Feb 2006. We are mostly working on trigger-related issues.

Probing Electroweak Physics of the Sandard Model at SLAC: SLD/SLC and BaBar

Incisive and precise tests of  (aka high-energy physics) have shown that (1) the  Standard Model of elementary particle physics is correct at low energy (< 100 GeV or so), and (2) the SM is incomplete and breaks down at a higher energy.
 
The BaBar experiment  at SLAC is exploring the physics of the b-quark in great detail. This has allowed BaBar to discover CP violation in the B system and to search for new physics in rare decay processes. CP violation represents an asymmetry between matter and anti-matter. A similar tiny asymmetry was also necessary in the early universe in order to give rise to the observed preponderence of matter over anti-matter in today's universe. BaBar is also exploring rare decay modes which can provide indirect evidence for new physics.

The SLD experiment at the Stanford Linear Accelerator Lab (SLAC) produced polarized electron beams which collided with positrons at a center of mass energy of 91 GeV to produce the Z0 particle (mass is about 91 GeV/c2 ). This provided the opportunity to make precision tests of the electroweak theory of the Standard Model by studying the Z0 production rate and its decay products in the SLD detector. One key result is a world best measurement of the weak mixing angle, also known as the Weinberg angle, which determines the ratio of the strength of the electromagnetic and weak force couplings in the electroweak theory. Its value was determined by SLD to be 0.23098 +/- 0.00026. Taken together with electroweak measurements from LEP at CERN, this predicts that the postulated Higgs particle can not be very massive, with rest energy less than about 200 GeV. This implies that the Higgs and/or the energy scale of electroweak symmetry breaking is just around the corner, and would be accessible at a future linear collider (see below). The SLC and LEP results at the Z0 are summarized in the following review article: Physics Reports 446 (2006) [hep-ex/0509008].


Probing New Physics at the TeraScale II: The International Linear Collider (ILC)


New Linear e+e- colliders ( ILC ) may be in the future of particle physics.
The HEP Advisory Panel report has (Jan 2002) given this its top priority.

Some LC studies which Ray has worked on:

Ray was previously a co-leader of the Calorimeter Working Group of American LC Physics Group and is currently
a co-leader for the SiD detector concept.. Here are some recent calorimeter-related talks and papers:

The Snowmass 1996 Top report is here (ps format) and the source tex and figures (gzipped tar) are here.

A General talks on LC Physics and Experimentation: LC Experiments and Detectors, APS Denver 2004.

Neutrino Physics at Fermilab

The electroweak force, as well as the force which binds the quarks (QCD), is being tested at low Q with high precision using a high-energy beam of neutrinos at the Fermi National Accelereator Laboratory (Fermilab) near Chicago. Ray, along with other UO physicists, is a member of the relatively small experimental group, known as NuTeV. Data taking ended Summer 1997.

Teaching:

Some  publications:

``Experimental Observation of Isolated Large Transverse Energy Electrons with Associated Missing Energy at sqrt{s} = 540 GeV'', Phys. Lett. 122B (1983) 103. (Discovery of the W particle.)

``Experimental Observation of Lepton Pairs of Invariant Mass Around 95 GeV/c^2 at the CERN SPS Collider'', Phys. Lett. 126B (1983) 398. (Discovery of the Z particle.)

``Measurements of Z Boson Resonance Parameters in e+e- Annihilation'', Phys. Rev. Lett. 63 (1989) 2173. (Discovery of number of neutrino species < 4.)

``Radiative Corrections to the Z0 Resonance'', Phys. Rev. D37 (1988) 56. (Some theory underlying the previous measurement.)

``First Observation of Beamstrahlung'', Phys. Rev. Lett. 62 (1989) 2381. (A new phenomena at e+e- linear colliders.)

``Measurement of Electron Beam Polarization from the Energy Asymmetry of Compton Scattered Photons'', R. Field, R. Frey, M. Woods, A. Arodzero, and J. Zhou, IEEE Trans. Nucl. Sci. 45 (1998) 670. (Technique for measurement of  beam polarization at SLC.)

``Top Quark Physics: Future Measurements", Summary Report for Snowmass 1996: New Directions for High Energy Physics, eds. D.G. Cassel, L.T. Gennari, and R.H. Siemann; hep-ph/9704243, March 1997. (Some of the exciting physics for the next accelerator at the high-energy frontier.)

``A High-Precision Measurement of the Left-Right  Z0 Cross-Section Asymmetry'', Phys. Rev. Lett. 84 (2000) 5945. (The final SLD ALR measurement and world best measurement of the electroweak mixing angle.)

``Observation of CP Violation in the B0 Meson System'', Phys. Rev. Lett. 87 (2001) 091801.  (Matter-antimatter asymmetry in the 3rd quark generation from BaBar.)

``Design Considerations for a Silicon-Tungsten Electromagnetic Calorimeter for a Linear Collider Detector,'' Proc. 10th International Conference on Calorimetry in High Energy Physics, World Scientific, 2002, R.-Y. Zhu ed., pg. 304. (A new way to do calorimetry for the LC.)

``Analysis of LIGO data for gravitational waves from binary neutron  stars,''  Phys. Rev. D 69, 122001 (2004). (One of the first LIGO observational results.)


rayfrey@uoregon.edu
Professor of Physics