Ann Heinson's Home Page

Research Physicist
Experimental High Energy Physics

UC Riverside Distinguished Researcher Award
for Non-Senate Faculty, 2002

  Department of Physics
  and Astronomy
  University of California
  Riverside, CA 92521-0413
  USA
   e-Mail:  ann.heinson@ucr.edu
              heinson@fnal.gov
  Phone:  (951) 827-5712
  Fax:      (951) 827-3345

The DØ Research Group at UC Riverside

 Ann Heinson
DØ Collaboration Banner
("The Map") 		Pictures of DØ Feynman Diagrams
DØ Map for Run II
DØ Map for Run II 		Click on the image
for eps and gif files
of the maps, and for
flag strips for talks
 2d view of DØ
2d view of DØ's tracking system 		Click on the images
for eps and gif files
of these figures and
other detector images
 ttbar feynman diagram
s-channel single top diagram
t-channel single top diagram 		Click on the images
for eps and gif files
of these and many
more Feynman diagrams
Research Interests
For the past fourteen years, I have been studying the top quark, which the DØ collaboration  co-discovered in 1995. I am particular interested in the production of single top quarks via the weak interaction. On the practical side, I have specialized in the design and use of tracking detectors, from wire chambers to silicon microstrip devices. I am currently co-leading the single top working group at DØ, and the Monte Carlo generators group, and I am responsible for DØ's Top Physics Group's web pages.

In May 2005, we submitted the results of the single top quark search for publication in Physics Letters B, and it was published in July: preprint, journal paper, technical summary, plain-english summary, news article, and pictures of the authors. In April 2006, we submitted a more detailed write-up of these results for publication in Physical Review D: here are the preprint and journal paper. My graduate student, Philip Perea, completed his Ph.D. dissertation, "Search for t-Channel Single Top Quark Production in ppbar Collisions at 1.96 TeV," in June 2006. In July 2006, we submitted a paper to Physics Letters B that sets limits on production of single top quarks from the decay of a heavy W-prime boson: here are the preprint and journal paper (published Septmmber 2006). In January 2007, we submitted a paper for publication on another new analysis that sets limits on the production of single top quarks from flavor-changing neutral currents, that is from a gluon-charm-top or gluon-up-top coupling: here are the preprint and journal paper (published November 2007).

This series of searches culminated in December 2006, when the DØ collaboration announced first evidence for single top quark production at the Tevatron, a most exciting event. We ruled out the hypothesis that the data does not contain single top quark events at the 99.965% level, and measured the rate that single top quarks are produced. We submitted a to Physical Review Letters (preprint, and journal paper (published May 2007), which is described in a technical summary and a plain-english summary. There were articles about this result in Fermilab Today, CERN Courier, Nature Physics, Physics Today, and Scientific American, where I am quoted. I gave a particle physics seminar at CERN on the result in January 2007. I was also interviewed for a news item on a local cable channel, Inland Valley News (the interview is the second item in the program), and have recorded an interview (part 1 and part 2) for the radio program Science Today. Here are the Fermilab press release and UC Riverside press release about the result. In June 2007, we updated two of the three analyses and combined the results to get a more precise result that rules out the background-only hypothesis at slightly high significance (3.6 standard deviations). This conference note describes the combination of the analyses. We submitted this result for publication in March 2008, in a long paper containing all the analysis details (preprint). This detailed paper was published in July 2008 (journal paper). A Physorg.com article about the paper appeared was published in August 2008.

The single top group followed up this analysis with three studies looking for physics beyond the standard model in single top quark events. The first search was for heavy W-prime boson resonances with decay to a top quark and a bottom antiquark, published in May 2008 (preprint, journal paper). The second search was for a charged Higgs boson also decaying to a top quark and bottom antiquark. This is much harder to search for as the Higgs mass is lower, so any resonance is more background-like. We submitted this result for publication in July 2008 (preprint). Both analyses set lower limits on the cross sections and masses of the predicted new particles. The third analysis studied the Wtb couplings in single top production to see if they are as predicted by the standard model, that is, only vector and left-handed in nature. We set limits on vector right-handed and tensor left- and right-handed components, and submitted a paper for publication in July 2008 (preprint).

Publications
As a member of the DØ collaboration, I am a coauthor of 239 papers in several international journals. Of these, 21 are on top quark physics using DØ's first dataset (1992-1996), and 29 are on top quark physics using DØ's second dataset (2002-present). There are 10 additional papers from previous collaborations and from individual work.
Of special interest are the following papers:
Conference Talks and Papers Other Publications Service for the DØ Experiment
Run I
Run II
Other Professional Service
The American Physical Society's Division of Particles and Fields Meeting was held at UC Riverside, August 2004, see www.dpf2004.org
(images are of posters I prepared, click on them for larger versions)
DPF welcome reception DPF student reception DPF Quarknet mentors' meeting DPF public lecture DPF women's lunch DPF chamber concert DPF Young Particle Physicists' lunch DPF town meeting DPF conference banquet
A Bit of History
I grew up in Billericay, S.E. England, and went to university in London. I graduated from Imperial College in 1984 with a B.Sc. in Physics, and in 1988 I got a Ph.D. in High Energy Physics, also from Imperial College. I wrote the first British Large Electron-Positron Collider (LEP) Ph.D. dissertation, on the ALEPH experiment. I then worked for the BBC at their engineering research labs until emigrating to California in 1989. I was a postdoctoral researcher at UC Irvine for three years, working on a rare kaon decay experiment E791 at Brookhaven National Laboratory, NY, and then moved to UC Riverside where I have been working on the DØ Experiment at Fermi National Accelerator Laboratory since 1992.

Academic Ancestry
My Ph.D. advisor was Peter Dornan, at Imperial College, London. His advisor was Otto Frisch, at Cambridge University. Frisch worked on the Manhattan Project during World War II. His advisor was Stefan Meyer, at the University of Technology, Vienna, Austria. Meyer worked with Ludwig Boltzmann in Vienna in the 1890's.
Ann and John at the Huntington Library, San Marino, CA, Nov 1999

John and me at the Huntington
Library Botanical Gardens,
San Marino, CA, November 1999

 Jeffrey and me, April 2002

Jeffrey and me
April 2002

 Jeffrey and me, March 2004

Two physicists
Riverside
March 2004

 At the Tran Quoc Pagoda, Hanoi, August 2004

Tran Quoc Pagoda
Hanoi, Vietnam
August 2004
Top Quark Symposium, Michigan, April 2005

Top Quark Symposium
Ann Arbor, Michigan
April 2005

 First day of kindergarten, September 2006

First day
of kindergarten
September 2006

 Submitting the single top evidence paper to PRL, December 2006

Submitting the single top
evidence paper to PRL
December 2006

 Making mince pies and pastries, December 2007

Getting ready
for the holidays
December 2007
In the photos are John Ellison and our son, Jeffrey
Last update: August 25, 2008