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Empty space in quantum chomodynamics showing the action density (like the energy density).

Research Activities of Prof. Jerry Gilfoyle

My research is focused on the experimental program at the Thomas Jefferson National Accelerator Laboratory to explore the quark-gluon nature of matter with an excursion into nuclear arms policy. I have also developed inquiry-based laboratories for introductory physics and undergraduate quantum mechanics. The nuclear physics research is supported by the US Department of Energy (grant DE-FG02-96ER40980).

A Russian nuclear missile sub is dismantled with support from the US cooperative threat reduction program.

Here are some links to background material about my research.

Introductory talk on my research at JLab is here.
A recent article on the work we are doing at Jefferson Lab along with a YouTube video here.
Here are introductions to nuclear and particle physics, quarks (1, 2, 3), gluons, the structure of the deuteron, the CLAS and CLAS12 detectors, and our local program at Richmond. Here is also some useful information on kinematics, units, etc, uncertainties, calculating uncertainties on efficiencies, cross sections and their use in nuclear physics. Some introductory readings are here, a link to my jlab webpage is here, my ENOTE log is here, and info on the emacs editor.
I am part of a large, international collaboration at Jefferson Lab (JLab) that built and maintains one of the major detectors called CLAS12. Some recent highlights are here and the Long-Range Plan for nuclear physics is here .
I was involved in science policy in the past as a scientific consultant for the Defense Threat Reduction Agency, US Department of Defense.
The website for calculating radiative corrections for the reaction D(e(pol),e'p)n is here.

The links here are to papers, reports, seminars, some news articles, and anything else I feel like putting in.

Update on the neutron magnetic form factor analysis is here. Presented at the CLAS Collaboration meeting, June 26, 2024.
Some past talks from Lamya Baashen (here) and me (here) for my summer research students.
Slides for GMn for the jeopardy review by the PAC on the Run Group B program are here, June 21, 2024.
Update on the neutron magnetic form factor analysis is here. Presented at the weekly Run Group B meeting, June 21, 2024.
Local talk in preparation for Jefferson Lab Open House, June 8, 2024 is here (June 7, 2024). The Scientific American article is here.
Jeopardy update for Run Group B in the CLAS Collaboration at JLab is here (Apr 9, 2024). Link to the document is here.
Amelia Karl's Senior Seminar second talk is here (Feb 14, 2024).
Lamya Baashen's thesis is here (Nov 16, 2023).
Talk on nuclear non-proliferation presented at the University of Richmond is here (Oct 26, 2023).
Amelia Karl's Senior Seminar first talk is here (Sep 20, 2023).
Sabbatical report for the University of Richmond, Sep 28, 2023 is here.
Status report to the SBS Collaboration meeting on the CLAS12 GMn experiment is here (Jul 17, 2023).
Report by Lamya Baashen to the CLAS Collaboration meeting on the CLAS12 neutron detection efficiency is here (Jul 14, 2023).
Report by Lamya Baashen to the CLAS Collaboration meeting on the GMn experiment is here (Jul 12, 2023).
Status report by Lamya Baashen to the RGB weekly meeting on the GMn measurement here (Jun 16, 2023).
Status report by Lamya Baashen to the RGB weekly meeting on the neutron detection efficiency (NDE) is here (Jun 9, 2023).
Status report on the simulation of the readout for the VMM3 chip being considered for use in the μwell detector is here (Mar 6, 2023).
Annual report submitted to DOE Mar 2, 2023 is here.
Informal talk on the GMn analysis on Feb 27, 2023 is here.
Slides from presentations from my week as Run Coordinator for Run Group C at JLab (Feb 15-22) are here and here.
Some recent results on fitting using a gaussian in the region near the peak μ ± σ (the cores) are here (Jan 12).
Some slides prepared to show the impact of the pass2 software development on the GMn data are here. The impact was nil when we improved the track selection and counting procedure (Dec 16).
Lamya Baashen from FIU gave a contributed talk on the GMn analysis at the Fall, 2022 meeting of the Division of Nuclear Physics of the APS in New Orleans. Her slides are here (Oct 28).
Three of my students I work with at JLab gave presentations at the Fall, 2022 meeting of the Division of Nuclear Physics of the APS in New Orleans. Jessie Hess's poster is here (pdf), Ryan Sanford's is here (pdf), (they learned a lot) and Rocco Moneiro Nunes Pesce's is here (pdf, Oct 28).
Talk presented at the University of Surrey, Guildford, UK on Oct 18, 2022 is here .
Informal presentation on GMn given Oct 10, 2022 is here .
Report on extracting the neutron yield to measure the neutron detection efficiency in the CLAS12 calorimeters to the Run Group B meeting on Oct 7, 2022 is here .
CLAS12-NOTE 2022-004 entitled "CLAS12 Reconstruction Resolution" Saina, Sanford, Ziegler, and Gilfoyle, Aug 15, 2022 is here .
Research group presentations on neutron detection efficiency in Run Group B for summer, 2022 are here: July 7, Aug 18, and Sep 1.
Lamya Baashen's progress report on the GMn analysis presented at the CLAS Collaboration meeting June 23, 2022 is here.
Archive of recent interdisciplinary investigations familial interaction dynamics is here.
Research group presentations on neutron detection efficiency in Run Group B for summer, 2022 are here: May 12, May 25, June 1, June 8, July 14.
Annual report for US Department of Energy grant is here. Submitted Mar 2.
Application for University support for a full-year sabbatical (2022-2023) at Jefferson Lab is here. Approved Mar 10.
Application for JLab travel support for a full-year sabbatical (2022-2023) is here (Jan 18, 2022).
Several students I work with at JLab gave presentations at the Fall, 2021 meeting of the Division of Nuclear Physics of the APS. Jessie Hess's contributed poster is here (pdf) and Ryan Sanford's is here (pdf).
Short proposal for sabbatical project at JLab is here.
Talk presented at Virginia Commonwealth University is here, Sep 24, 2021.
University of Richmond story about the DOE grant renewal is here, Sep 14, 2021.
Proposal for University of Richmond faculty sabbatical is here (Sep 13, 2021).
Some comments on science policy in a recent issue of URNow are here (Sep 6, 2021).
Report by Lamya Baashen to RGB meeting July 23, 2021 is here(pdf) and here (pptx).
Report by Lamya Baashen on e-p selection and comparison with simulation is here (May 21, 2021).
Presentation for the PAC48 Jeopardy Review Run Group B (RGB) is here. Remaining beamtime was approved.
Recent results on extracting the neutron detection efficiency presented at the Run Group B weekly meeting, Feb 26, 2021 is here.
Adrien Saini's masters thesis is here. Adrien is a University of Surrey masters student who did research in 2020 with my group.
Status of GMn analysis for Run Group B Pass 1 review for fall, 2019 run is here. Held Jan 22, 2021.
Service work proposal for 2021 is here (submitted Dec, 2020).
Grant renewal proposal submitted to DOE is here (submitted Nov 23, 2020). Approved April, 2021. University announcement of the award is here.
Two of the students I work with at JLab gave presentations at the Fall, 2020 meeting of the Division of Nuclear Physics of the APS. Lamya Baashen's (FIU) contributed talk is here (pdf) and here (pptx). Adrian Saina's (Surrey) poster is here (pdf).
A former undergraduate research student of mine, Keegan Sherman, receives prestigious US Department of Energy research award here.
Talk presented by Adrian Saina at the CLAS Software meeting October 8, 2020 is here.
Draft of GMn slides for JLab PAC jeopardy talk by Silvia Niccolai is here in pdf and pptx formats, Sep 14, 2020. Full talk is here .
Short introductory talk about my research presented at Richmond Physics Seminar is here, Sep 2, 2020.
Lamya Baashen's talk on the neutron detection efficiency (NDE) at the CLAS Collaboration Meeting is here, July 22, 2020.
Update on the GMn analysis for the CLAS Collaboration meeting is here, July 21, 2020. Full RGB talk is here.
CLAS12-NOTE 2020-002 entitled "CLAS12 Drift Chamber Reconstruction Software Unit Test" by Armstrong, Ziegler, and Gilfoyle is here, July 6, 2020.
RGB report on the GMn NDE measurement is here, June 19, 2020.
JLab Jeopardy Update is here, June 9, 2020.
Update on GMn analysis for spring, 2020 CLAS Collaboration meeting is here, Mar 24, 2020.
Annual report for DOE Office of Science, Nuclear Physics Program is here, Mar 6, 2020.
Michael Armstrong's masters thesis at the University of Surrey is here, Jan 14, 2020.
CLAS12 Run Coordinator report for Monday, January 12, 2020 is here.
Three of my students, Michael Armstrong, Matthew Heyrich, and Xiaodi Hu, presented posters at the fall meeting of the Division of Nuclear Physics of the APS, October 15, 2019. The posters are here and here.
Alignment report for July 9, 2019 is here.
Alignment report for June 11, 2019 is here.
National Academy of Sciences report on sexual harassment of women is here.
Alignment report for May 21, 2019 is here.
Alignment report for March 26, 2019 is here.
Run coordinator report for March 11, 2019 is here.
General talk about the physics at JLab and a bit on the LHC presented at St. Catherine's School on Feb 7, 2019 is here.
Annual report for DOE Office of Science, Nuclear Physics Program is here, Jan 31, 2019.
Discussion on extracting the NDE from the RGA data is here, Jan 15, 2019.
Short talk for the Society of Physics Students Research Introduction at the University of Richmond, Nov 14, 2018 is here.
One of my students, Ben Weinstein, presented a poster at the fall meeting of the Division of Nuclear Physics of the APS, October 26, 2018. The poster is here.
Link to tar file with references on the CLAS12 GMn experiment and other background material is here. Link to tar file with Alexander Balsamo's work is here.
Study of type-1 and type-2, cosmic-ray events reconstructed in the SVT/MMT with Tracker using the no-shim geometry is here, Sep 3, 2018.
Study of type-1 and type-2, cosmic-ray events reconstructed in the SVT/MMT with Tracker is here, Aug 27, 2018.
Study of type-3, events originating from the target in the SVT is here, Aug 20, 2018.
Study of type-2, cosmic-ray events in the SVT is here, Aug 7, 2018.
Some plots showing the alignment status are here, July 19, 2018.
Talk on measuring the elastic electromagnetic form factors during the 12 GeV era at JLab presented at the University of Surrey (Guildford, UK) is here, May 8, 2018.
Some introductory readings on my research are here.
An introductory talk on my research at JLab is here.
First check on the SVT alignment with data from the engineering run is here (March 26, 2018).
Talk entitled Putting the Genie Back in the Bottle: The Science of Nuclear Non-Proliferation presented at the University of Richmond is here, February 9, 2018.
Status report on the SVT geometry implementation in the cosmic-ray reconstruction is here (Jan 8, 2018).
Grant renewal proposal submitted to DOE is here (submitted Nov 28, 2017, approved April, 2018).
CLAS Collaboration Chair Procedures, CLAS12 Note 2017-015, November 25, 2017 is here.
One of my students, Alexander Balsamo, presented a poster at the fall meeting of the Division of Nuclear Physics of the APS, October 26, 2017. The poster is here.
Talk on the CLAS Collaboration organization for the Ready-for-Science Review, September 25-26, 2017 is here (pptx) and here (pdf). The alignment slides are here.
Invited talk on measuring the elastic electromagnetic form factors during the 12 GeV era at JLab presented at the "47th International Symposium on Multiparticle Dynamics" (Tlaxcala City, Mexico) is here, Sep 12, 2017. The conference photo is here.
After updating to the latest gemc and coatjava version the issue with the sign of centroid residuals persists. The report is here for September 6, 2017.
Report on centroid residuals sign issue in the SVT alignment is here for August 10, 2017.
CLAS12-NOTE on the SVT geometry code (based on Peter Davies masters thesis) is here for August 9, 2017.
Alignment presentation for Saclay group is here, August 3, 2017.
Status report on the SVT alignment showing test of Type-2 analysis code applied to Type-1 tracks is here, August 1, 2017.
Draft of Alexander Balsamo's abstract for his poster at the Conference Experience for Undergraduates at the fall, 2017 DNP meeting is here.
Charge to the First Experiment Analysis Review is here, July 25, 2017.
Report on the SVT alignment geometry calculations and formulas for the DOCA and its derivatives for millepede is here, July 17, 2017.
Status report on the SVT alignment project showing improvement in millepede misalignments as code is debugged is here, July 10, 2017.
For the June, 2017 CLAS Collaboration meeting here are my talks introducing the CLAS12 Workshop, introducing the CLAS Collaboration Meeting, and the closeout (Jun 13-16, 2017).
For the June, 2017 CLAS Collaboration meeting here slides for the Run Group Discussion on the GMn dual target and the SVT alignment.
Slides for Yuri's Monday meeting talk are here, May 22, 2017.
Talk entitled Putting the Genie Back in the Bottle: The Science of Nuclear Non-Proliferation presented at the Virginia Academy of Science Annual Meeting is here, May 18, 2017 along with the abstract.
Slides for Run Group B meeting are here, May 2, 2017.
Status report on the SVT geometry and alignment project including derivation of DOCA formula is here, April 24, 2017.
Omair Alam's senior thesis entitled "Dual-Target Design" is here, April 2, 2017.
For the March, 2017 CLAS Collaboration meeting here are my talks introducing the CLAS12 Workshop, introducing the CLAS Collaoration Meeting, and the closeout (Mar 28-31, 2017). There also a picture of all of us here.
Annual report for DOE is here (Jan 30, 2017).
First look at Type-2 events with combined type-1+type-2 residuals is here (Jan 16, 2017).
Slides for meeting of Analysis Group January 13, 2017.
Quick summary of Peter Davies' research project is here, Dec 15, 2016.
For the November, 2016 CLAS Collaboration meeting here are my talks introducing the meeting, on the Transition to CLAS12 Operations, and the closeout which includes the Common Tools report (Nov 1-4, 2016). There also a picture of all of us here.
Slides on alignment for CLAS12 Software Review are here (Nov 11, 2016).
My students presented posters at the Conference Experience for Undergraduates (CEU) during the fall meeting of the APS Division of Nuclear Physics (DNP) in Vancouver, BC on October 14, 2016. They are Keegan Sherman, David Brakman, Alexander Balsamo, and Peter Davies.
Using new geometry code for Type 1 tracks is here (Sep 19, 2016).
More progress on the geometry for non-Type 1 (Type 2) tracks is here (Sep 12, 2016).
Progress on geometry for non-Type 1 tracks is here (Sep 8, 2016).
Short discussion of GlueX gitHub repository structure is here.
Short research introduction for our Senior/Junior seminar is here.
Quality check on clas12 cosmic ray reconstruction from gemc simulation is here.
First look at real cosmic ray data in the SVT with millepede is here.
More on the effect of SVT region 1 shifts in simulation on the millepede results are here.
CLAS chair reports for CLAS Collaboration meeting, Jun 16-18 are here and here.
Summary slides for First Experiment Workshop are here, for June 15, 2016.
Effect of SVT region 1 shifts in simulation on the millepede results are here.
Plots for millepede mailing list are here: fig 1, fig 2, and millepede output,
Study of effect of different constraints on alignment results using simulated SVT data is here for May 22, 2016.
The senior thesis of Keegan Sherman, one of my research students, is here (April, 2016).
Gzipped tar file with EIC stuff is here (273 MByte, May 18, 2016).
Fixed a bug in the partial derivative calculation for Δx in mille. Results are here for May 16, 2016.
Update on alignment with millepede using simulated SVT data is here for May 12, 2016.
Updated research introduction is here.
Update on alignment and first pass at millepede with simulated SVT data is here for May 5, 2016.
JLab economic impact description for the 2016 Open House is is here.
Talk on measurements of the neutron magnetic form factor at JLab presented at ECT* in Trento, Italy, April 21, 2016 is here.
Summary of alignment status for Yuri Gotra is here for April 4, 2016.
Update on alignment stuff is here for Mar 24, 2016.
Report on alignment stuff is here for Mar 7, 2016.
CLAS chair reports for CLAS Collaboration meeting, Feb 23-26 are here and here.
Talk on recent progress on the CLAS12 TOF reconstruction software at the CLAS12 First Experiment Workshop is here (pdf), Feb 23, 2016.
Code management discussion for CLAS12 Software meeting is here (Feb 4, 2016).
Annual report for DOE is here (Feb 2, 2016).
Some stuff on CLAS chair is here which came out Jan 15 along with an article in the Richmond Time-Dispatch.
I spun the torus here and here (second file is big).
Sensitivity of millepede fits to constraints is here.
Software planning estimates for TOF software and track-based alignment of the SVT is here.
Listing of Physics bachelor's degrees including the University of Richmond Physics Department among those primarily undergraduate institutions with the largest number of bachelor's degrees is here from November, 2015.
First steps to understand how to use millepede for alignment of the CLAS12 SVT is here (updated).
Poster on "Future Measurements of the Nucleon Elastic Electromagnetic Form Factors at Jefferson Lab" is here and here. Presented at Electromagnetic Interactions in Nucleons and Nuclei 2015 in Paphos, Cyprus, Tuesday, Nov 3, 2015. Files for Steve Christo are here.
My research students have presented their work at the Conference Experience for Undergraduates poster session at the fall, 2015 meeting of the Division of Nuclear Physics of the American Physical Society in Sante Fe, NM. The posters are here for David Brakman, Omair Alam (pdf and pptx), and Keegan Sherman presented Oct 29, 2015.
CLAS chair reports for CLAS Collaboration meeting, Oct 20-23 are here and here.
Alignment report for the CLAS12 'First Paper' Workshop on Oct 20, 2015 is here.
A front-page article in the Richmond Times-Dispatch about the EIC is here.
More on using Regions 1-3 in cosmic ray data and first look at survey results is here. Fixed bug in ΔR.
Removing region 4 from measured cosmic ray data is here.
Simulation results and cutting off the ears is here.
First look at alignment in the CLAS12 SVT is here.
Updated research introduction is here.
Response for fifth structure function analysis is here along with supporting files wvoCalcs1.pdf, wvoCalcsWeighted2.6n.pdf, wvoCalcsWeighted2.6r.pdf.
Chair discussion slide is here.
IQS article is here.
Slide for software validation study on neutron detection efficiency is here.
One-page description of JLab impact is here.
One page description of JLab experiment to measure the magnetic form faction of the neutron is here.
Proposal submitted to the JSA/SURA Sabbatical Support Program March 2, 2015 is here.
Talk on the CLAS12 software user environment presented at the 12 GeV Software Review, Feb 10, 2015 is here in pdf and pptx.
A tar file with the latex source for the Stefan's Law lab is here.
Science policy talk presented at the University of Richmond on January 30, 2015 is here.
Enhanced sabbatical proposal submitted to the University of Richmond on December 1, 2014 is here.
Grant renewal proposal submitted to the US Department of Energy on November 24, 2014 is here. Approved April, 2015.
Talk on CLAS12 event reconstruction software development by users for the 12 GeV Software Review is here in pptx and here in pdf, presented Nov 6, 2014.
Proposal for Richmond summer fellowship is here, submitted Oct 17, 2014.
Two of my undergraduate students presented posters at the Conference Experience for Undergraduates at the fall, 2014 meeting of the Division of Nuclear Physics of the APS. Keegan Sherman's poster is here and Omair Alam's is here.
Lab manual for IQS, F2 physics is here, September 22, 2014.
CLAS-NOTE 2014-008 updating the description of the geometry of the electromagnetic calorimeter (EC) in CLAS12 is here, September 17, 2014.
CLAS-NOTE 2014-007 describing the QUEEG event generator to simulate quasielastic scattering off nucleons in deuterium is here, September 5, 2014.
University of Richmond, full-year, sabbatical proposal is here, September 1, 2014.
Proposal to provide travel funds for JLab users to visit Washington, DC on Nuclear Physics Day on Capitol Hill is here and here.
Invited talk on measuring the elastic electromagnetic form factors during the 12 GeV era at JLab presented at the "Sixth Workshop on Hadron Physics and Opportunities in the US" (Lanzhou, China) is here.
CLAS-NOTE 2014-003 on the Time-of-Flight reconstruction software adapted from Alex Colvill's masters thesis is here, May 1, 2014.
One-pager for Nuclear Physics Day in Washington, DC April 28, 2014 is here.
One of my research students, Liam Murray, presented his senior seminar talk on Feb, 26. His talk is here (pdf) and here (pptx).
Alex Colvill worked with me toward his master's degree at the University of Surrey. His thesis is here. (February, 2014).
Annual report submitted to DOE is here. (February 4, 2014).
Talk on the measuring the elastic electromagnetic form factors during the 12 GeV era at JLab presented at the "Workshop on High-Energy Physics in the LHC Era" (Valparaiso, Chile) is here (Dec 17, 2013).
Talk on the CLAS12 user environment for the 12 GeV Software Review (Nov 25, 2013) is here in pptx and here in pdf.
Slides prepared for the panel discussion of MOOCs at the annual meeting of the Southeastern Section of the American Physical Society (SESAPS) are here (Nov 22, 2013).
My student, Alex Colvill, who is obtaining an M.Phys degree from the University of Surrey in the UK presented a poster at the same meeting (SESAPS, Nov 22, 2013).
Samples of discovery-based, introductory physics laboratories are here and here in PostScript format (fall, 2013).
Two of my students presented posters of their research at the Fall, 2013 Meeting of the Division of Nuclear Physics of the APS. Liam Murray's poster is here and Justin Ruger's is here (Oct 24, 2013).
A visit by Paul Stevenson from Surrey on Sep 9, 2013 to our group at JLab is described here on the Blog of the Isotopes.
Updated research introduction is here.
Midterm report for Alex Colvill is here.
Briefing materials for the 2013, DOE comparative panel review are here. The talk is here, (June 13, 2013).
Second response to fifth structure function review is here, March 24, 2013.
Summary of progress on the CLAS21 reconstruction code for the forward time-of-flight (FTOF) detector here (May 30, 2013).
Annual report submitted to DOE is here. (February 27, 2013).
First response to fifth structure function review is here, submitted Feb 18, 2013.
Final report to the NSF on the development of the Nuclear Physics/Cosmology computing cluster is here, submitted Nov 30, 2012.
Two of my students presented posters of their research at the Fall, 2012 Meeting of the Division of Nuclear Physics of the APS. Liam Murray's poster is here and Keegan Sherman's is here.
An article in the university newspaper (the Collegian) is here (Sep 6, 2012).
Talk presented at the Nuclear Physics Working Group Meeting, October 12, 2012 is here along with a summary.
Slides for IQS discussion are here.
Submitted version of the fifth structure function analysis note is here.
Summary of GMn experiment for NSAC review is here.
Supplemental proposal to DOE to fund a joint University of Richmond/University of Surrey masters student for one year to work on JLab physics is here. Approved July, 2012.
Presentation on CLAS12 computing requirement including the slides, calculations (updated 10/30/13), and the write-up. The final report is here.
Slide on project for software review in June on Quasielastic neutron detection efficiency for SRP meeting is here, March 9, 2012.
Talk entitled Putting the Genie Back in the Bottle: The Science of Nuclear Non-Proliferation presented at the University of Virginia Physics Department is here, January 20, 2012.
Talk entitled Hunting for Quarks presented at the University of Virginia chapter of the Society of Physics Students is here, January 20, 2012.
Slides for gemc meeting are here, December 13, 2011.
Draft Memorandum of Understanding between the Jefferson Science Associates and the University of Richmond for work at Jeffferson Lab is here, November 21, 2011.
Grant renewal proposal submitted to the US Department of Energy on November 17, 2011 is here.
One of my students presented a poster at the fall, 2011 Conference Experience for Undergraduates at the Division of Nuclear Physics meeting in East Lansing, MI Oct 27, 2011. Chris Musalo's poster is here.
Talk on CLAS12 Software Planning presented at the Oct, 2011 CLAS Collaboration meeting is here, Oct 13, 2011.
Annual report on the NSF Major Research Instrumentation grant is here, October 10, 2011.
Invited talk entitled Future Measurements of Elastic Electromagnetic Form Factors at Jefferson Lab presented at PINAN11 in Marrakech, Morocco September 26, 2011.
Draft of the CLAS-NOTE on the implementation of the electromagnetic calorimeter in the CLAS12 physics-based simulation gemc is here, September 9, 2011. The final version is here.
Draft of the CLAS-NOTE on the simulated neutron detection efficiency in the CLAS12 FTOF is here, October 1, 2011. The final version is here.
Report from the INT program "Gluons and the quark sea at high energies: distributions, polarization, tomography" is here, August 5, 2011.
JLab pizza seminar entitled Putting the Genie Back in the Bottle: The Science of Nuclear Non-Proliferation presented June 29, 2011.
Presentation to local elementary and middle school science teachers on nuclear physics at is here, June 27, 2011.
Discussion of 12 GeV IT Readiness Review is here, June 21, 2011.
Draft of the analysis note is here, May 30, 2011.
Presentation for the CLAS12 Software Group on the CLAS12 Information Technology Readiness Review, Jefferson Lab, May 20, 2011.
The senior seminar for one of my research students Mark Moog on the Neutron Detection Efficiency of the CLAS12 Detector is here, April, 2011.
Invited talk entitled Putting the Genie Back in the Bottle: The Science of Nuclear Non-Proliferation presented at the University of Richmond, April 13, 2011.
Invited talk entitled Putting the Genie Back in the Bottle: The Science of Nuclear Non-Proliferation presented at Catholic University, April 6, 2011.
Talk on the fifth structure function of the deuteron presented at the March, 2011 CLAS Collaboration meeting is here along with a summary. (March 10, 2011).
Annual report submitted to DOE is here. (February 18, 2011).
Combined research introduction on nuclear physics, non-proliferation, and science careers presented at the University of Richmond, Nov. 10, 2010 is here with a University report here.
Three of my students presented posters at the fall, 2010 Conference Experience for Undergraduates at the Division of Nuclear Physics meeting in Santa Fe, NM on Nov 4, 2010. Here are the posters for Mark, Chris, and Josh.
Paper presented on the CLAS12 Reconstruction and Analysis Framework (CLARA) by Vardan Gyurjyan at CLHEP, October, 2010 is here.
Presentation on Bose-Einstein Correlations at the Electron-Ion Collider, Institute for Nuclear Theory, University of Washington, Seattle, Washington, October 12, 2010 is here.
Talk entitled Few-Body Physics with CLAS presented at the 21st European Conference on Few-Body Problems in Physics, Salamanca, Spain, Aug 30, 2010. The proceedings are here.
Report on the CLAS12 Software Workshop presented at the CLAS Collaboration Meeting on June 17, 2010 is here.
Presentation on Simulation Results for CLAS12 From gemc at the CLAS12 Software Workshop, May 25, 2010. The introduction to the Workshop is here and the talks are here.
Invited talk entitled Measuring the Magnetic Form Factor of the Neutron in CLAS12, presented at the Workshop on Exclusive Reactions at High Momentum Transfer, Jefferson Lab, May 19, 2010. The proceedings are here.
Slides announcing the 2010 CLAS12 Software Workshop.
Calina Copos did her senior seminar research on her work with me on simulations of the D(e,e'p)n reaction here.
Invited talk entitled Putting the Genie Back in the Bottle: The Science of Nuclear Non-Proliferation, presented at the Joint Meeting of the New England Section and the New York State Section of the American Physical Society, Modern Nuclear Applications, Union College, April 24, 2010.
Report to the CLAS Collaboration on the Nuclear Physics Working Group meeting held March 19, 2010 is here.
Report to the CLAS Collaboration on the CLAS12 Software session is here, plenary session, March 18, 2010.
We are organizing the CLAS12 Software Workshop to be held at the University of Richmond on May 25-26. The slide is here and the website is here.
Presentation on recent progress implementing the electromagnetic calorimeter (EC) in the CLAS12 Geant4 simulation (gemc) is here, presented March 17, 2010.
Annual report submitted to DOE is here. (February 15, 2010).
Materials for the Physics Department review, January 26, 2010 are here.
Update talk on the approved CLAS12 experiment to measure the magnetic form factor of the neutron, Jan 28, 2010. Thirty days of beamtime and A- rating, January 29, 2010.
Update on the approved CLAS12 experiment to measure the magnetic form factor of the neutron. Submitted Jan 5, 2010.
Letter-of-Intent submitted to PAC35 to measure the polarized EMC effect in CLAS12. Submitted Dec 15, 2009.
Letter-of-Intent submitted to PAC35 to develop a low-momentum, recoil detector to study QCD and the internal structure of hadrons immersed in the nuclear medium. Submitted Dec 15, 2009.
Proposal to measure the neutron magnetic form factor in Hall A. Submitted Dec 15, 2009.
Nuclear Physics Working Group Report presented at the plenary session of the CLAS Collaboration meeting November 21, 2009 is here (pdf) and here (ppt).
Talk on recent software developments for the CLAS12 simulation gemc including adding the EC is here.
Invited talk (short version here) prepared for the Women in Science and Technology Workshop at JLab, Nov 17, 2009.
In October, 2009 three of my students presented posters at the meeting of the Division of Nuclear Physics of the American Physical Society. The meeting was in Kona, Hawaii and here is Calina's poster, Matt's and Mark's.
Contributed talk on GMn presented at the Mini-Symposium on Electromagnetic Form Factors - from the Nucleon to Nuclei I, Fall DNP, October 14, 2009.
Proposal to the JSA/SURA Initiatives fund to hold a CLAS12 software workshop in May, 2010 is here (PDF) and here (doc version) (August 17, 2009). Approved October, 2009.
Nuclear Physics Working Group report for the June, 2009 CLAS Collaboration meeting is here in PDF and PPT formats (June 13, 2009).
Talk entitled 'Nuclear Physics and National Security' presented at Franklin and Marshall College, June 6, 2009 is here.
Talk entitled 'Precise Measurement of the Neutron Magnetic Form Factor' presented to the Physics Division at Argonne National Laboratory, June 1, 2009 is here.
The G_Mⁿ paper is out here and the arXiv version is here. Jeff's thesis is here.
Presentations on nuclear physics and science policy and on the future physics program at JLab as part of the University of Richmond short course on Nuclear Physics and Society.
Nuclear Physics Working Group Report presented at the plenary session of the CLAS Collaboration meeting February 28, 2009 is here (pdf) and here (ppt).
Full-year sabbatical proposal to analyze the low-Q² G_Mⁿ data and work on CLAS12 software sent to JSA/SURA is here (Feb 12, 2009).
One-page summary of GMn for DOE is here (Feb 3, 2009).
Computing cluster proposal submitted to the NSF Major Research Instrumentation program is here (January 23, 2009); approved September, 2009.
Beam time proposal to JLab PAC34 to measure the neutron magnetic form factor in Hall A at Q² up 18 GeV² is here. Submitted Dec 15, 2008.
Enhanced sabbatical proposal is here. Submitted Dec 4, 2008.
Renewal proposal submitted to the US Department of Energy's Nuclear Physics Program on November 20, 2008 is here.
Research introduction presented in the Gottwald auditorium November 18, 2008 is here and here.
Preprint of paper on our measurement of the magnetic form factor of the neutron is here.
Nuclear Physics Working Group Report presented at the plenary session of the CLAS Collaboration meeting November 1, 2008 is here.
Posters presented at the fall, 2008 meeting of the Division of Nuclear Physics of the APS in Oakland, CA by Mark Moog and Matt Jordan.
The CLAS Analysis Note 2008-103 entitled A high precision measurement of the neutron magnetic form factor using the CLAS detector was approved October 1, 2008.
Poster presented at the Gordon Conference on Photonuclear Reactions in Tilton, New Hampshire, August 10-15, 2008 is here and some pictures.
Nuclear Physics Working Group Report presented at the plenary session of the CLAS Collaboration meeting May 31, 2008 is here.
Update on the analysis of the G_Mⁿ measurement using the ratio method in CLAS presented in the plenary session of the CLAS Collaboration meeting May 29, 2008 is here.
Kirill Dergachev's Senior thesis was on "CLAS 12 Simulation Analysis and Optimization".
Invited talk 'Review of QCD Processes in Nuclear matter at Jefferson Lab' presented at the XVI Workshop on Deep Inelastic Scattering and Related Subjects' in London, England along with a summary and the proceedings. (April 8, 2008).
Annual report submitted to DOE is here. (February 13, 2008).
Computing cluster proposal submitted to the NSF Major Research Instrumentation program is here. (January 23, 2008).
Kuri Gill is one of my students graduating this year (2008) who worked with me on simulations of the CLAS detector for our analysis of deuteron electrodisintegration.
Slides for a panel on academic careers at the headquarters of the American Association for the Advancement of Science, December 6, 2007 are here.
Nuclear Physics Working Group Report presented at the plenary session of the CLAS Collaboration meeting Nov 2, 2007 is here.
Talk on homeland security presented to the Brandermill/Midlothian/Wood Lake Lion's Club, November 8, 2007 is here.
Short research introduction given at Richmond on October 30, 2007 and another presentation for Con Beausang's nuclear physics course on October 23, 2007.
Invited talk given as part of the Conference Experience for Undergraduates program at the fall, 2007 meeting of the Division of Nuclear Physics of the APS is here along with some pictures.
Student poster by Kirill Dergachev presented at the fall, 2007 DNP meeting is here.
Talk on Nuclear Physics at the University of Richmond presented at the American School of Madagascar, September 12, 2007, Antananarivo, Madagascar.
Talk on Measuring Form Factors and Structure Functions with CLAS presented to HEPMAD07, September 11, 2007 in Antananarivo, Madagascar. The proceedings are here.
Talk on the proposal entitled Measurement of the Neutron Magnetic Form Factor at High Q2 Using the Ratio Method on Deuterium presented to JLab PAC32, August 7, 2007.
Beam time proposal entitled Measurement of the Neutron Magnetic Form Factor at High Q2 Using the Ratio Method on Deuterium submitted to the JLab PAC as part of the 12-GeV Upgrade program, June 20, 2007. Approved August 8, 2007.
Talk on the beam time proposal entitled Measurement of the Neutron Magnetic Form Factor at High Q2 Using the Ratio Method on Deuterium, plenary session, CLAS Collaboration meeting June 12, 2007.
Nuclear Physics Working Group Report presented at the plenary session of the CLAS Collaboration meeting June 14, 2007 is here.
Invited talk entitled A High-Precision Measurement of G_Mⁿ with CLAS presented at the Workshop on Exclusive Reactions at High Momentum Transfer (JLab, May 21-24, 2007). The proceedings is here.
The Hall-B, 12-GeV Upgrade Workshop was held at JLab May 14-15, 2007. I gave an overview of the CLAS12 reconstruction progress and the software report.
One of my students, Kristen Greenholt, was a Physics/Political Science double major. I was on the review committee for her Political Science thesis here. See below for her physics thesis.
Proposal submitted to the National Science Foundation's program on Explosives and Related Threats on May 2, 2007 is here.
Two of my research students, Kristen Greenholt and Rusty Burrell, are graduating this year (2007). Their senior theses were written on their work with me on hadronic fiducial cuts and simulations of the D(e,e'p)n reaction.
The CLAS12 tracking system was reviewed in Feb, 2007 here.
Proposal submitted to the National Science Foundation's Major Research Instrumentation Program on January 25, 2007 is here.
Talk on homeland security presented to the 5400 Club at the Jewish Community Center, January 15, 2007 is here.
Renewal proposal submitted to the US Department of Energy's Nuclear Physics Program on November 13, 2006 is here.
Contributed talk at the fall, 2006 DNP meeting is here along with two posters presented by my students Kristen Greenholt and Rusty Burrell and Kuri Gill.
Proposal submitted to the National Science Foundation Nuclear Physics Program is here submitted September 27, 2006.
Proposal submitted to the Defense Universities Research Instrumentation Program, Army Research Office, is here with the budget justification here.
Letter of intent to measure the magnetic form factor of the neutron submitted July 7, 2006 to the JLab PAC30 is here.
Proposal to measure quark propagation and fragmentation in cold nuclear matter submitted July 7, 2006 to the JLab PAC30 is here.
Progress report on measurements of the fifth structure function of the deuteron presented at the Nuclear Physics Working Group meeting during the CLAS Collaboration meeting March 3, 2006.
CLAS technical report (CLAS-Note 2005-022)entitled 'Radiative Corrections for Deuteron Electrodisintegration' can be found here.
Two of my students presented posters at the Fall, 2005 DNP meeting of the American Physical Society in Maui, Hawaii. Kristen Greenholt's poster is here and Rusty Burrell's is here.
Nuclear Physics Working Group report presented at the plenary session of the CLAS Collaboration meeting June 18, 2005.
Progress report on the fifth structure function of the deuteron presented at the Nuclear Physics Working Group meeting during the CLAS Collaboration meeting June 17, 2005.
Science policy talk given to the Physics Department at Virginia Commonwealth University, April 22, 2005.
Two of my students presented posters at the April, 2005 meeting of the American Physical Society in Tampa, Florida. Kristen Greenholt's poster is here and Rusty Burrell's is here.
Progress report is here on electrodisintegration of the deuteron presented at the Nuclear Physics Working Group meeting during the CLAS Collaboration meeting Feb 25, 2005.
Grant renewal proposal for the US Department of Energy is here submitted November 22, 2004.
Science policy talk given to the Physics Department at Idaho State University, October 5, 2004.
Presentation to a joint Math/Physics seminar at the University of Richmond, September 22, 2004.
Short presentation to the University of Richmond Interdisciplinary Science Seminar Series, September 22, 2004.
Webpage describing the radiative corrections used for the E5 running period at JLab along with copies of the code is here. A talk from the June, 2004 CLAS Collaboration meeting is here.
CLAS Approved Analysis presentation at the plenary session of the CLAS Collaboration Meeting, November 13, 2003. The written version is here.
Measurement of Polarized Structure Function sigma(LT') for p(e(vec),e'p)pi0 from single pi0 electroproduction in the Delta resonance region, K. Joo, et al. (The CLAS Collaboration), Physical Review C, Rapid Communications, 68, 032201 (2003).
Study of the Delta(1232) using single and double polarization asymmetries, A. Biselli, et al. (The CLAS Collaboration), Physical Review C 68, 035202 (2003).
Public lecture on weapons of mass destruction presented as part of Union College's Perspectives at the Nott Memorial series, October 15, 2003.
Science policy seminar presented at the Union College Department of Physics, October 15, 2003.
Nuclear Physics seminar presented at the University of Richmond Department of Physics, September 29, 2003.
We have developed our own laboratory manual for introductory physics at the University of Richmond. Somes samples of the material are here for the fall and spring semesters in PostScript format.
Presentation to the Multihadron Working Group during the CLAS Collaboration Meeting, July 25, 2003.
Observation of Nuclear Scaling in the A(e,e') Reaction at x_Bjorken > 1, K.Egiyan, et al. (The CLAS Collaboration), Physical Review C 68, 014313, (2003).
Our collaboration at JLab (CLAS) has discovered a new form of matter containing five quarks instead of the usual two or three. It's called the pentaquark.
A link to the recent work of the American Physics Society's Task Force on Countering Terrorism including a short piece I wrote about `Swarm Intelligence'.
When is nothing really something? Find out here.
Measurement of ep -> e'p π⁺ π^- and baryon resonance analysis, Physical Review Letters 91 022002, (2003), M. Ripani, et al. (The CLAS Collaboration) - The cross section for the reaction ep ® e' p π⁺ π^- was measured in the resonance region for 1.4 < W < 2.1 GeV and 0.5 < Q² < 1.5 GeV²/c², using the CLAS detector at Jefferson Laboratory.Data shows resonant structures not visible in previous experiments. The comparison of our data to a phenomenological prediction using available information on N^* and Δ states shows an evident discrepancy. A better description of the data is obtained either by a sizable change of the properties of the P₁₃(1720) resonance or by introducing a new baryon state, not reported in published analyses.
Measurement of Inclusive Spin Structure Fuctions of the Deuteron with CLAS, J. Yun, et al. (The CLAS Collaboration), The Physical Review C, 67, 055204 (2003) - We report the results of a new measurement of the spin structure functions of the deuteron in the region of moderate momentum transfer (Q² = 0.27 - 1.3 (GeV²)) and final hadronic state mass in the resonance region (W = 1.08 - 2.0 GeV). We scattered a 2.5 GeV polarized continuous electron beam at Jefferson Lab off a dynamically polarized cryogenic solid state target (¹⁵ND₃) and detected the scattered electrons with the CEBAF Large Acceptance Spectrometer (CLAS). From our data, we extract the longitudinal double spin asymmetry A_|| and the spin structure function g₁^d. Our data are generally in good agreement with existing data from SLAC where they overlap, and they represent a substantial improvement in statistical precision. We compare our results with expectations for resonance asymmetries and extrapolated deep inelastic scaling results. Finally, we evaluate the first moment of the structure function g₁^d and study its approach to both the deep inelastic limit and large Q² and to the Gerasimov-Drell-Hearn sum rule at the real photon limit (Q² ® 0). We find that the first moment varies rapidly in the Q² range of our experiment and crosses zero around Q² ~ 0.65 (GeV/c)², indicating the dominance of the Δ resonance at these momentum transfers.
The CEBAF Large Acceptance Spectrometer, Nuclear Instruments and Methods 503/3, 513 (2003), B. Mecking, et al., A collaboration of 34 institutions has assembled the CEBAF Large Accceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. A program of about 60 experiments will use this detector to study structures and interactions of mesons, nucleons, and nuclei using polarized and unpolarized electron and photon probes. A six-coil toroidal super-conducting magnet provides the magnetic field necessary to determine the momenta of charged particles as they are tracked using drift chambers. Cherenkov counters, time-of-flight scintillators and electromagnetic calorimeters provide particle identification. Fast triggering and high data acquisition rates allow operation at luminocities of 10³⁴/cm²/s.
First Measurement of Transferred Polarization in the Exclusive e(pol)p -> e'K+Lambda(pol) Reaction, D. Carman, et al. The CLAS Collaboration Physical Review Letters 90, 131804 (2003). The first measurements of the transferred polarization for the exclusive e(pol)p -> e'K+Lambda(pol) reaction have been performed in Hall B at the Thomas Jefferson National Accelerator Facility using the CLAS spectrometer. A 2.567 GeV electron beam was used to measure the hyperon polarization over a range of Q2 from 0.3 to 1.5 (GeV/c)2, W from 1.6 to 2.15 GeV, and over the full center-of-mass angular range of the K+ meson. Comparison with predictions of hadrodynamic models indicates strong sensitivity to the underlying resonance contributions. Contrary to the expectations of the widely used 3P0 model of open-flavor hadron strong decays, our data suggest that the intermediate state s-sbar quark pair is produced with spins anti-aligned.
This is a compressed PostScript file from my CLAS Collaboration talk on out-of-plane measurements of deuteron electrodisintegration (Feb 28, 2003).
A Complete Measurement of the F2 Proton Structure Function in the Resonance Region and the Evaluation of the Moments, M. Osipenko, et al. (The CLAS Collaboration), Physical Review D 67, 092001 (2003). We measured the inclusive electron-proton cross section in the nucleon resonance region (W < 2.5 GeV) at momentum transfers Q^2 below 4.5 (GeV/c)^2 with the CLAS detector. The large acceptance of CLAS allowed for the first time the measurement of the cross section in a simultaneously wide, two-dimennsional range of Q^2 and x, making it possible to perform an integration of the data at fixed Q^2 over the whole significant x-interval. From these data, we extracted the F2 structure function and studied the Q^2 evolution of its moments, Mn(Q^2), in order to estimate higher twist contributions. The statistical and systematic uncertainties of th JLAB data allow a precise extraction of the higher twists and therefore accurate theoretical predictions of the latter are now called for to allow a meaningful comparison.
This is a brochure (in pdf format) for a pair of recent talks at the Science Museum of Virginia along with the talks (1,2).
An essay about my experiences as a AAAS Defense Policy Fellow is here.
Photoproduction of the omega meson on the proton at large mementum transfer by Marco Battaglieri, et al., (the CLAS Collaboration), Physical Review Letters 90, 022002 (2003). The differential cross section, d sigma/dt, for omega meson exclusive photoproduction on the proton above the resonance region (2.6 < W < 2.9 GeV) was measured up to a momentum transfer -t = 5 GeV^2 using the CLAS detector at Jefferson Laboratory. The omega channel was identified by detecting proton and pi+ in the final state and using missing mass technique. While the low momentum transfer region shows the typical diffreation pattern expected from Pomeron and Reggion-exchange, at large -t the differential cross section has a flat behavior. This feature can be explanied introducing quark interchange processes, beside the QCD-inspired two-gluon exchange.
I was recently a member of the Task Force on Countering Terrorism of the American Physics Society described here and here.
eta photoproduction on the proton for photon energies from 0.75 to 1.95 GeV M. Dugger, et al., (The CLAS Collaboration) Phys. Rev. Lett. 89, 222002 (2002) Differential cross sections for the reaction gamma p -> eta p have been measured with a tagged photon beam for incident photon energies from 0.75 to 1.95 GeV. Mesons were identified through missing mass reconstruction using kinematical information for the protons scattered in the production process. The data provide the first extensive angular distribution measurements for the process above W = 1.75 GeV. Comparison with preliminary results from a constituent quark model support the suggestion that a third S11 resonance with mass ~1.8 GeV couples to the (eta N) channel.
We have developed our own laboratory manual for introductory physics at the University of Richmond. Somes samples of the material are here for the fall and spring semesters in PostScript format.
First Measurement of the Double Spin Asymmetry in e(pol)p(pol) -> e'pi+n in the Resonance Region, . DeVita, et al. (The CLAS Collaboration), Phys. Rev. Lett. 88, 082001 (2002) The first measurement of the double spin asymmetry for exclusive single pi+ electroproduction from protons has been performed in Hall-B at the Thomas Jefferson National Accelerator Facility using CLAS. A 2.6-GeV polarized electron beam was incident on a polarized solid NH3 target. The double spin asymmetry Aep was measured in the resonance region for a range of momentum transfer squared, 0.35 < Q2 < 1.5 GeV2, and for a range of pi+ center-of-mass polar angle, 0.25 < cos(thetacm) < 1. Comparison with predictions of phenomenological models shows strong sensitivity to resonance contributions. Helicity-1/2 transitions are found to be dominant in the second and third resonance regions. The measured asymmetry is consistant with a faster rise with Q2 of the helicity asymmetry A1 for the F15(1680) resonance than expected from the analysis of the unpolarized data.
Two articles about my work in DTRA are in the newsletter of the American Association for the Advancement of Science here and in the journal Nature.
"Loose Nukes: Fissile Material Security in Russia", colloquium presented at the Institute for Nuclear and Particle Physics, Ohio University, Athens, OH, April 3, 2002.
Successful proposal to the Major Research Instrumentation (MRI) program at the National Science Foundation for a supercomputing cluster.
Observation of exclusive deeply virtual Compton scattering in polarized electron beam asymmetry measurements Physical Review Letters 87, 182002 (2001) S. Stepanyan et al. (The CLAS Collaboration) We report the first results of the beam spin asymmetry measured in the reaction e + p -> e + p + gamma at a beam energy of 4.25 GeV. A large asymmetry with a sin(phi) modulation is observed, as predicted for the interference term of Deeply Virtual Compton Scattering and the Bethe-Heitler process. The amplitude of this modulation is alpha = 0.202 +/- 0.028. In leading-order and leading-twist pQCD, the alpha is directly proportional to the imaginary part of the DVCS amplitude.
"Science in the Public Interest: The AAAS Science and Engineering Fellowships", Conference on Science for the Public Good, Virginia Commonwealth University, Richmond, VA, June 1, 2001 (ps format).
Using Nuclear Materials to Prevent Nuclear Proliferation - Study performed during 1999-2000 as a Defense Policy Fellow for the American Association for the Advancement of Science, Science and Global Security, 9, 81 (2001). A Word version of the paper is here, a PDF version is here, and a one-page summary of the work is here.
Electroproduction of the Lambda(1520) Hyperon , Physical Review, C64, 044601 (2001). S. Barrow et al (The CLAS Collaboration) Abstract: The reaction ep --> e' K+ Lambda(1520) with Lambda(1520) --> p' K- was studied at electron beam energies of 4.05, 4.25, and 4.46 GeV, using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The cos(theta_K+), phi_K+, Q^2, and W dependencies of Lambda(1520) electroproduction are presented for the kinematic region 0.9 < Q^2 < 2.4 GeV^2 and 1.95 < W < 2.65 GeV. Also, the Q^2 dependence of the Lambda(1520) decay angular distribution is presented for the first time. The cos(theta_K+) angular distributions suggest t-channel diagrams dominate the production process. Fits to the Lambda(1520) t-channel helicity frame decay angular distributions indicate the m_z = +- 1/2 parentage accounts for about 60% of the total yield, which suggests this reaction has a significant contribution from t-channel processes with either K+ or longitudinal coupling to an exchanged K*. The Q^2 dependence of the Lambda(1520) production cross section is the same as that observed for Lambda(1116) photo- and electroproduction.
Exclusive electroproduction of phi mesons at 4.2 GeV. Physical Review C 63, 065205-1 (2001). K. Lukashin, et al (The CLAS Collaboration) We studied the exclusive reaction e p --> e' p' phi using the phi --> K^+ K^- decay mode. The data were collected using a 4.2 GeV incident electron beam and the CLAS detector at Jefferson Lab. Our experiment covers the range in Q^2 from 0.7 to 2.2 GeV^2, and W from 2.0 to 2.6 GeV. Taken together with all previous data, we find a consistent picture of phi production on the proton. Our measurement shows the expected decrease of the t-slope with the vector meson formation time c Delta tau below 2 fm. At = 0.6 fm, we measure b_phi = 2.27 +- 0.42 GeV^-2. The cross section dependence on W as W^{0.2+-0.1} at Q^2 = 1.3 GeV^2 was determined by comparison with phi production at HERA after correcting for threshold effects. This is the same dependence as observed in photoproduction.
The ep --> e'p(eta) reaction at and above the S11(1535) baryon resonance , Physical Review Letters 86, 1702 (2001). R. Thompson, et al (The CLAS Collaboration) New cross sections for the reaction ep-->e'p(eta) are reported for the total center of mass energy W = 1.5 - 1.86 GeV and invariant momentum transfer Q^2 = 0.25 - 1.5 (GeV/c)^2. This large kinematic range allows extraction of important new information about response functions, photocouplings, and (eta)N coupling at W ~ 1.7 GeV; this is shown to come from interference between S and P waves and can be interpreted in terms of known resonances. Improved values are derived for the photon coupling amplitude for the S11(1535) resonance.
Seminar talk, fall, 2000 and others 1, 2, 3, 3b (ps format)
Photoproduction of phi(1020) Mesons on the Proton at Large Momentum Transfer. Physical Review Letters 85, 4682 (2000). - E. Anciant, et al (The CLAS Collaboration), The cross-section for phi meson photoproduction on the proton has been measured for the first time up to a four-momentum transfer t = -4 GeV^2, using the CLAS detector at at Thomas Jefferson National Accelerator Facility. At low four-momentum transfer, the differential cross section is well-described by Pomeron exchange. At large four-momentum transfer, above -t = 1.8 GeV^2, the data support a model where the Pomeron is resolved into its simplest component, two gluons, which may couple to any quark in the proton and in the phi.
The CLAS Drift Chamber System, NIM A449 (2000) 81. , M.D. Mestayer, D.S. Carman, B. Asavapibhop, F.J. Barbosa, P. Bonneau, S.B. Christo, G.E. Dodge, T. Dooling, W.S. Duncan, S.A. Dytman, R. Feuerbach, G.P. Gilfoyle, V. Gyurjyan, K.H. Hicks, R.S. Hicks, C.E. Hyde-Wright, G. Jacobs, A. Klein, F.J. Klein, M.V. Kossov, S.E. Kuhn, R.A. Magahiz, R.W. Major, C. Martin, T. McGuckin, J. McNabb, R.A. Miskimen, J.A. Mueller, B.B. Niczyporuk, J. O'Meara, L.M. Qin, B.A. Raue, J. Robb, F. Roudot, R.A. Schumacher, D.J. Tedeschi, R.A. Thompson, D. Tilles, W. Tuzel. VanSyoc, M.F. Vineyard, L.B. Weinstein, G.R. Wilkin, A. Yegneswaran, J. Yun, Experimental Hall B at Jefferson Laboratory houses the CEBAF Large Acceptance Spectrometer, the magnetic field of which is produced by a superconducting toroid. The six coils of this toroid divide the detector azimuthally into six sectors, each of which contains three large multi-layer drift chambers for tracking charged particles produced from a fixed target on the toroidal axis. Within the 18 drift chambers are a total of 35,148 individually instrumented hexagonal drift cells. The novel geometry of these chambers provides for good tracking resolution and efficiency, along with large acceptance. The design and construction challenges posed by these large-scale detectors are described, and detailed results are presented from in-beam measurements.
Archiving in Physics - Instructions for backing up data on some of the Physics Department computers.
Simulations of lambda(1520) Electroproduction - Initial stages of an undergraduate project to test the new computer cluster in the University of Richmond Physics Department. The results will be used to generate the acceptance for the CLAS for electrodproduction of the lambda(1520) baryon measured during the e1 running period.
Elastic Peak Monitoring for the CLAS - Presentation by Dave Vermette at the XIV Meeting of the International Society of Physics Students held in Helsinki, Finland in August, 1999. The abstract is here.
Time Histories Status - Update of time histories project presented at the June, 1999 CLAS Collaboration meeting. It is also available as a compressed (with gzip) postscript file here.
Time Histories - Project to make the results of online recsis analysis automatically available on the web during experiments at Jefferson Laboratory (January, 1999).
Measuring/Monitoring Tmax and Tmin. Talk presented at the CLAS tracking workshop, November, 1998.
A New Teaching Approach to Quantum Mechanical Tunneling. Paper presented at the 1998 Conference on Computational Physics in Granada, Spain. A copy of the transparencies is here.
Online version of RECSIS
Proposal to the NSF Instrumentation and laboratory Improvement program to obtain video technology for introductory phyiscs is here. Approved spring, 1995.
CEBAF
The CEBAF Large Acceptance Spectrometer (CLAS)
Electroproduction of the f₀(975) Scalar Meson (Experiment 89-043)
Effects of Discrete Ionization in the CLAS Drift Chambers (ps format)
Spatial Resolution of the Nose Cone Prototype Drift Chamber (ps format)
Data Definitions for the CLAS Drift Chambers (ps format)
Drift Velocity Calibration of the CLAS (ps format)
3-2 contacts

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