My interest for a number of years has been experimentally measuring rare or forbidden processes to probe for physics beyond the Standard Model. Currently my main focus is a large new experiment being developed at Fermilab called Mu2e (pronounced 'mew to ee', short for muon to electron conversion) . Its goal is to see for the first time, or set new limits on the existence of, a muon converting into an electron without any accompanying neutrinos.This is accomplished by first capturing negative muons in atomic orbit around a target nucleus (aluminum in our case)- this is needed so that the muon and electron can bounce off of the nucleus in order to conserve energy and momentum in the reaction. Mu2e is an example of a rare reaction which, if it exists, signals the presence of new physics. The project has initial approval and CD0 approval from the DOE, and we expect to get CD1 approval in summer 2011. I am currently serving as co-spokesman of this project.
A few years ago I joined the nEDM experiment to be conducted at the SNS (high flux spallation neutron source) at Oak Ridge, now in development stage. I am in charge of electronics and simulations for this experiment. The goal is to measure the electric dipole moment (EDM) of the neutron to unprecedented precision. Permanent EDM's are a sign of CP violation but have not yet been seen in elementary particles or neutral atoms. New sources of CP violation are needed to help explain the baryon asymmetry of the universe.
Our experiment to measure the positive muon lifetime, at the Paul Schirrer Institut innear Zurich, Switzerland, is now complete, with a result on the muon lifetime with an accuracy many times better than previous experiments.
For many years I worked with my colleagues Professors Carey and Roberts on the muon g-2 experiment. It measured the magnetic anomaly of the muon to 1/2 part per million, and the result disagrees with the Standard Model prediction by more than three standard deviations. A new version of this experiment is being strated at Fermilab to improve the meaurement by a factor of 2 to 4., to see if the discrepancy withtheory persists. If it does, then this is a signal for the presence of new physics.
Also, in the 1990's, I led the Boston university participation in the CPLEAR experment at CERN. It is notewrthy for being the only experiment which has detected T violation in an elementary particle interaction.
- B.S. 1968, M.S. 1970, Ph.D. 1975, Carnegie-Mellon University
- Postodoctoral Fellow, Caltech, 1974-1976
- Postodoctoral Fellow, Lawrence Berkeley Laboratory, 1976-1979
- B.S. 1968, M.S. 1970, Ph. D. 1975, Carnegie-Mellon University, Advisor: Professor Peter Barnes
- Postoctoral Fellowships: Caltech, 1974-1976; Lawrence Berkeley Laboratory, 1976-1979
- Assistant Professor, Boston University, 1979-1986
- Associate Professor, Boston University, 1986-1992
- Professor, Boston University, 1992-present.
Fellow, American Physical Society
Our muon lifetime experiment (MuLan Collaboration), at the Paul Scherrer Institut, which grew out of Brookhaven E821, has published a 1 ppm measurement of the muon lifetime in Physical Review Letters, which improves the precision of the Fermi constant for muon decay. See Phys. Rev. Lett. 106, 041803 (2011), and Phys.Rev. D 87, 052003 (2013)
Muon (g-2) project at Fermilab
This experiment will upgrade of BNL E821. Boston University physicists are playing a leading role. The goal is a factor of four improvement on the precision on the muon anomalous magnetic moment, which will require 21 times the data, approximately 200 million analyzed events, and a factor of three improvement in the systematic errors. The goal is to clarify whether the evidence obtained at Brookhaven is a signal of New Physics entering at the loop level, or a statistical fluctuation..
Neutrinoless Muon to Electron Conversion
The goal of the Mu2e experiment (pronounced 'mew to ee') is to measure the rate of a muon converting into an electron with no accompanying neutrinos to a precision 10000 times better than previous experiments. Such a violation of charged lepton flavor conservation has never been seen by charged leptons such as muons and electrons. It has already been seen for neutral leptons, neutrinos, in the form of neutrino oscillations. A positive signal is a sure sign of new physics. Mu2e is one of the flagship experiments in the future Fermilab program. It currently has CD0 level (initial) approval at the DOE and is in the process of obtaining CD1 status (funding for a full detailed engineering design).