Dr. Ashot Gasparian
Professor Ashot Gasparian
Department of Physics
Marteena Hall, office #301
Degree Date Institution
Ph.D. 1987 Yerevan Physics Institute, Yerevan, Republic of Armenia.
Thesis: “Measurement of the Forward Compton Cross Sections on 4He at Few GeV Energies”.
M.S. 1974 Yerevan State University, Yerevan, Republic of Armenia.
Thesis: “Development of Angular Reconstruction Algorithms for the Optical Spark Chambers”.
B.S. 1974 Yerevan State University, Yerevan, Republic of Armenia.
Experimental intermediate energy nuclear and particle physics; Precision tests of basic symmetries of QCD; Chiral symmetry breaking effects and the quark-gluon structure of the light pseudoscalar mesons; Precision measurements of the light neutral mesons (?o,?,?/) life time; Precision measurement of the proton charge radius; Monte Carlo simulations to design and optimize precision experiments in nuclear/particle physics; Development of nuclear and particle physics instrumentation and detection systems.
Positions and Academic Experience:
Position Date Institution
* Professor of Physics 2009 – present NC A&T State University, Greensboro, NC
Department of Physics
* Associate Professor 2005 – 2009 NC A&T State University, Greensboro, NC
Department of Physics
* Associate Professor 2002 – 2005 NC A&T SU, “bridge” position with Jefferson
Laboratory, Newport News, VA
* Research Professor 1997 – 2002 Hampton University, Hampton, VA,
Department of Physics
* Research Scholar 1995 – 1997 University of Kentucky, Lexington, KY,
Physics and Astronomy Department
* Visiting Scientist 1992 – 1995 Jefferson Laboratory, Newport News, VA,
* Head of the Scientific 1989 - 1995 Yerevan Physics Institute, Yerevan, Armenia,
Subdivision#122 Physics Division
* Senior Scientist, 1974 - 1995 Yerevan Physics Institute, Yerevan, Armenia,
Research Scientist Physics Division
Recent Research Proposals and Developments:
* Led the development of a new research proposal: “High Precision Measurement of the Proton Charge Radius”. Presented at JLab PAC38 in August, 2011. The proposal (PR12-11-106) received a high scientific interest from PAC38 and approved with a C2 condition to develop a windowless hydrogen gas flow target.
* Led the development of the 12 GeV experimental proposal: “A Precision Measurement of the eta Radiative Decay Width via the Primakoff Effect”. Presented at JLab PAC35 and PAC37. The proposal approved by PAC35 (E12-10-011) and reapproved by PAC37 with high scientific rating (A-) in January 2011.
* Played a leading role on the development of an experimental proposal: “An Updated High Precision Measurement of the Neutral Pion Lifetime via the Primakoff Effect”. Presented at JLab PAC33, the proposal was approved with a high scientific rating (E08-023), January 2008.
* Led the PrimEx collaboration efforts to develop the experimental research project for the Jefferson Lab “12 GeV Energy Upgrade” program: “Electromagnetic Properties of Pseudoscalar Mesons via the Primakoff Effect”. Presented at JLab PAC23, January, 2003. The proposal is included in the “Executive Summary” of the “Science Driving the 12 GeV JLab Upgrade”.
* Led the PrimEx collaboration efforts to develop the updated proposal: “A Precision Measurement of the Neutral Pion Lifetime via the Primakoff Effect”. Presented at JLab PAC22. The proposal was re-approved with highest scientific (A) rating (E02-103) in July, 2002.
Recent Conferences and Invited Talks:
* Presentation at international conference “Rutherford Centennial Conference on Nuclear Physics”, “New Results from the PrimEx Experiments”, Manchester, UK, August 8, 2011.
* Invited talk at international conference “XV International Conference on Symmetry Methods in Physics”, “High Precision Measurement of the Neutral Pion Life Time”, Yerevan, Armenia, July 26, 2011.
* Invited talk at Workshop “Search for a New Gauge Boson at JLab”, Newport News, VA, September 20-21, 2010.
* Invited talk at “8th International Conference on Electromagnetic Interactions with Nucleus and Nuclei” (EINN-2009), Milos Island, Greece, October 2, 2009.
* Invited talk at “Transverse Partonic Structure of Hadrons”, International Workshop, June 21-26, 2009, Yerevan, Armenia.
* Invited talk at “X International Workshop on Electron-Nucleus Scattering”, Marciana Marina, Italy, June, 2008.
* Invited talk at “International Workshop on High Density Nuclear Physics and QCD”, Yerevan, Armenia, October, 2008.
* Invited talk at the “The 4th Electron Ion Collider” workshop, Hampton University, Hampton, VA, USA, May 23, 2008.
* Invited talk at the APS April, 2007 meeting, “New Measurements of the Neutral Pion Lifetime as a Precision Test of Chiral Anomaly”, Jacksonville April, 2007.
* Invited talk at “XI International Conference on Calorimetry in High Energy Physics”, “High Performance PbWO4 Hybrid Calorimeter at Jefferson Lab”, Perugia, Italy, March, 2004.
* Invited talk at South-Eastern section of APS meeting: “New Generation Precision Experiments to Test Chiral Anomaly”. SESAPS-2003, Wilmington, NC US, Nov. 2003.
* Invited talk at “X International Workshop: Chiral Dynamics 2003”, “The ?o Lifetime Experiment and Future Plans at JLab”, Bonn, Germany, Sept. 2003.
* Invited talk at “10th International Conference on Calorimetry in High Energy Physics”, “High Precision PrimEx Experimental Setup”, Pasadena, CA USA, 2002.
Recent Research Grants Received:
* Principal Investigator of the research award: “Study of the Fundamental Symmetry Braking Effects via the Precision Experiments at JLab”, funded by the National Science Foundation (NSF award PHY-0855543, for the period September 2009 to August 2012, total amount $480,000), with Dr. R. Pedroni (NC A&T SU) as co-PI.
* Principal Investigator of the research award: “Precision Study of the Radiative Decay Widths of Light Pseudoscalar Mesons via the Primakoff Effect”, funded by the National Science Foundation (NSF award PHY-0600252, for the period September 2006 to August 2008, total amount $300,000), with Dr. R. Pedroni (NC A&T SU) as co-PI.
* Principal Investigator of the research award “Study of Electromagnetic Structure of Light Pseudoscalar Mesons via the Primakoff Effect”, funded by the National Science Foundation (NSF award PHY-0245407, for the period September 2003 to August 2006, total amount ~$1,000,000), with S. Danagoulian and A. Ahmidouch (NC A&T SU) as co-PI’s.
* Principal Investigator (Project Director) of the NSF sub-award No. 02-0346 to NC A&T SU with connection to NSF “COSM” PFC award (PHY-0114343) to Hampton University. Total amount ~$600.000 for the period 2002-2009 to support student’s research training.
* Principal Investigator of the NSF Major Research Instrumentation (MRI) research award: “Development of a High Resolution Detection System for the Precision Measurement of the Neutral Pion Lifetime at Jefferson Lab”, funded by NSF (award #PHY-0079840, for the period 2000 – 2004, total amount: ~$1,000,000), with D. Dale (UKy), R.. Miskimen, (UMass),
S. Danagoulian (NC A&T SU) as co-PI’s.
Other Recent Professional Experiences:
* Reviewed research proposals for the National Science Foundation.
* Panel member to review the scientific program to fund “Research Team Projects” at Republic of Chile, Santiago, Chile, September 5-9, 2011.
* Reviewed research proposals and progress reports for the Program for Science and Technology, “CONICYT”, Santiago, Chile.
I have taught the following courses at North Carolina A&T State University for about the last ten years.
Course # Title Term Year
* PHYS-225 College Physics I Fall 2005,06,07, 08,09,11
Spring 06,07,08,09,10, 11
* PHYS-406 Introduction to Modern Physics Spring 06,07,08,09,10
* PHYS-420 Quantum Mechanics-I Fall 02,06
* PHYS-422 Quantum Mechanics-II Spring 03,07
* PHYS-451 Introduction to Astrophysics Spring 2011
* PHYS-468 Nuclear/Elementary Particle Physics Fall 05,07,08,09,11
* PHYS-620 Quantum Mechanics-I Fall 02,03,04,05, 06,07,08,09,11
* PHYS-720 Quantum Mechanics-II Spring 02,03,04,05,06,08,09,10,11
* PHYS-738 Nuclear Physics Fall 05,07,08,09,11
* PHYS-770 Graduate Research Fall 03,04,05, 07,08,11
* PHYS-791 Master’s Thesis Fall 03,04,05, 06,08,09
* PHYS-792 Master’s Thesis Spring 04,05,06,08,09
Recent Research Supervision and Advising:
* Post-doctoral Research Associates:
o Zafar Ahmed (2011-present), new postdoctoral research associate, supported by the NSF grant. He is starting to work on the data analysis from the PrimEx-II experiment. He will also play an active role in the preparation of the new ???? experiment in Hall D and in the development of the proton charge radius experiment for the next few years.
o Pawel Ambrozewicz (2006-2011), postdoctoral research associate, supported by the NSF grant. Worked on the preparation, execution and initial data analysis t of the PrimEx-II experiment. He was also actively involved in the development of a new experimental proposal for the precision measurement of the ???? decay width in Hall D at JLab.
o Raphael Demirchyan (2003-05), postdoctoral research associate, supported by the NSF grant. Worked on the development, construction and execution of the ?0 life time experiment in Hall B at Jefferson Lab.
* Graduate students at NC A&T SU:
o Mbala R. Mayanga, (2009-10) First year graduate student, worked on his thesis project. From spring, 2010 moved to Ph.D. program with the Engineering College at NC A&T.
o Subhash Khanal (2009), Master of Science (M.S.), the thesis project title: “Investigation of Beam Position Reconstruction Methods for the PrimEx Experiment at Jefferson Lab”.
o Kelli Hardy (2006), Master of Science (M.S.), the thesis project title: “Monitoring the Integrity of the PrimEx Experimental Setup Using Compton Scattering”.
o Marvin Payen, (2005), Master of Science (M.S.), the thesis project title: “The Performance and Characteristics of the HYCAL Calorimeter for the ?o Life Time Measurement at JLab”.
* Undergraduate Students:
During my tenure at North Carolina A&T State University, I have supervised more than fifteen undergraduate students training in my research project at JLab.
University and Departmental Services:
At North Carolina A&T State University I have served in the following committees:
* In the Department of Physics:
Committee Participation Year
o Graduate Coordinator Chair and Coordinator 2003-05, 2011 - present
o Tenure, Reappointment Committee Member 2007 - present
o Library Liaison Chair 2005 - present
o Curriculum Committee Member 2005 – present, Chair 2007 – 09
* In the College of Arts & Sciences
o Curriculum Committee Member 2005 - present
o Academic Policy Committee Member 2005 - 07
o Colloquium Series Committee Member 2005 – 07
* At the University level:
o Reappointment, Promotion Member 2009 – 10
and Tenure (RPT) Review Committee
o Radiation Safety Committee Member 2007 - present
* American Physical Society (Member)
* JLab PrimEx collaboration, (Leader)
* JLab Hall D collaboration (Member)
* JLab Hall C collaboration (Member)
* JLab Hall A collaboration (Member)
* JLab Hall B collaboration (Limited Member
Summary of Research Interests
My primary research area is experimental nuclear and particle physics using electromagnetic probes in the few GeV energy range. Over the years, I have worked at various national and international research laboratories (Yerevan Physics Institute, Armenia, Joint Institute of Nuclear Research, Dubna, Russia, Jefferson Laboratory, Newport News, VA, USA) with a variety of detector systems and different types of beams and targets.
My current research interests are focused in the study of the fundamental symmetry braking phenomena in the theory of Quantum Chromodynamics (QCD). These effects are directly manifested in the electromagnetic properties of the light pseudoscalar mesons. In the limit of massless u, d and s quarks the classical QCD Lagrangian exhibits a SU(3)L x SU(3)R x U(1)A symmetry. In full quantum theory the U(1)A axial symmetry is explicitly broken, leading to chiral anomaly in QCD. On the other hand, the SU(3)L x SU(3)R symmetry is spontaneously broken, giving rise to eight massless pseudoscalar Goldstone bosons. The effects of SU(3) and isospin breaking by the u, d and s quark mass differences lead to important mixing effects among the light pseudoscalar mesons. Understanding the electromagnetic properties of these particles is, therefore, fundamentally important in probing the basic symmetries of QCD. One of the most interesting systems in intermediate-energy QCD is represented by the three neutral light pseudoscalar mesons, ?0, ?, and ?/. The study of the two-photon decay widths of these mesons are of fundamental importance in determining the light quark mass ratios and the mixing effects between their quantum states. These studies will provide a test of the low energy limit of QCD in a relatively clean setting, and a better understanding of the origin and dynamics of symmetry breaking effects and their mechanisms in physics.
In the past several years, I have led the scientific efforts of the initial group of physicists from different world-wide leading universities to develop an experimental proposal “A Precision Measurement of the Neutral Pion Lifetime via the Primakoff Effect”. This proposal submitted to the Jefferson Laboratory (JLab) Program Advisory Committees (PAC15 and PAC22) was approved with highest scientific rating (A). I am the spokesperson and contact-person for this experiment (JLab experiment E02-103). From the very beginning, I have led the group’s efforts to form a scientific collaboration (PrimEx at JLab) capable of developing and carrying out this experimental project. The PrimEx collaboration currently is one of the largest and productive collaborations at JLab, with its more than fifteen nationwide leading university groups and five international institutions. For this precision measurement a new state-of-the-art experimental setup needed to be developed and built in Hall B at JLab. In the year of 2000, the National Science Foundation (NSF) funded this project for $1,000,000 under the Major Research Instrumentation (MRI) grant, “Development of a High Resolution Detection System for the Precision Measurement of the Neutral Pion Lifetime at Jefferson Lab” (NSF award PHY-0079840). I was the Principal Investigator for this grant, which ended in the year of 2004.
The PrimEx collaboration, in the past several years, successfully developed, constructed and commissioned the new high precision detection system in the Hall B beam-line. The first execution of the experiment was performed during 2004 and produced a collection of rich experimental data. The collaboration succeeded in extracting the first results of the ?0 life time with a high precision from the experimental data set. The preliminary results have been reported at the APS April, 2007 meeting as an invited talk and released during the press conference organized by the American Institute of Physics (AIP). The results of this first experiment are reported in leading international conferences and workshops and have been already published in leading journals. Recently in the fall of 2010, we have performed the second stage of this experiment (PrimEx-II) with larger statistics and better accuracies in the experimental parameters. We are currently analyzing the experimental data set and anticipate extracting the pion lifetime with an unprecedented 1.5% precision level.
In the past decade the JLab administration was actively searching for leading experimental projects to support the CEBAF beam energy upgrade to 12 GeV. I have led the PrimEx collaboration efforts to develop a comprehensive experimental project to utilize this new energy domain. As a result, a proposal “Precision Measurements of the Electromagnetic Properties of Pseudoscalar Mesons at 12 GeV via the Primakoff Effect” was developed and submitted to all three High Energy Special Program Advisory Committees (PAC18, 23 and 27). With the PAC’s strong recommendations, the 12 GeV PrimEx project is included in the “Executive Summary” section of the “The Science Driving the 12 GeV Upgrade of CEBAF” as a one of the major physics programs for Jefferson Lab in the upcoming decades.
The precise experimental determination of ?0???, ???? and ?/??? radiative decay widths will lead to a direct determination of the mixing angles and quark mass ratios. One of the impacts of a precise measurement of the ???? decay width would be in the corresponding improvement in the determination of the rest of the ? partial decay widths, as these are currently determined using the ???? decay width and the corresponding branching ratios, known from other experiments. The ??3? decay is of particular importance since it is driven by the isospin breaking effect, and thus gives a model independent access to the quark mass ratio (mu – md)/ms. Therefore, the new experiment, developed by the PrimEx collaboration for the ???? precision measurement, will significantly improve the determination of the light quark mass ratios. It is important to mention that the quark masses are free input parameters in the Standard Model, and can only be determined by experiment.
For the last four years, I lead the efforts of the PrimEx collaboration to develop a new proposal for the eta-Primakoff experiment at JLab. The new proposal “A Precision Measurement of the ? Radiative Decay Width via the Primakoff Effect” was submitted to PAC35 at JLab in January of 2010. It was successfully approved initially by PAC35 and recently reapproved by PAC37 to perform a high precision experiment (with 3% total error) in Hall D using the GlueX experimental setup, which is currently being developed and constructed with the 12 GeV energy upgrade program of Jefferson Lab.
In the past few years, there is a renewed interest in particle physics to search for new “dark matter” particles in the fixed-target experiments using the intermediate energy electron accelerators. There are certain theoretical speculations that these particles, if they exist, may interact with the matter known to the Standard Model through a “kinetic mixing” mechanism and with an extremely weak interaction force. Our PrimEx experimental setup with its high resolution, fast and large geometrical acceptance together with the high intensity CEBAF electron beam is well suited to perform first generation search experiments. The first results from the Monte Carlo simulations, and draft suggestions for these possible experiments, were reported in the recent workshop “Search for a New Gauge Boson at JLab” held in September of 2010 at Jefferson Laboratory. Currently I am working with a group to develop a full research proposal for these search experiments for the next Program Advisory Committee at JLab.
The proton charge radius is one of the fundamental quantities in physics. Precision knowledge of its value is critically important for the understanding of the structure of nucleon in terms of quark and gluon degrees of freedom in the theory of strong interactions - QCD. On the other hand, the precise determination of the charge radius is very important for atomic physics to test calculations of bound-state QED and, in particular, spectroscopy of atomic hydrogen.
Very recently, in 2010, new results from two measurements of the charge radius, done by different methods, have been published in the leading journals. The first one is from new studies of muonic hydrogen performed at PSI providing a factor of ten more precise results than all previous experiments: rp = 0.84184(67) fm. The second result is from Mainz done with the traditional ep-scattering method giving rp = 0.879(8) fm and it is consistent with previous results within the experimental errors. The muonic hydrogen result is up to a seven standard deviation smaller than the average value from all other previous experiments, triggering the well-known “proton charge radius crisis” in the hadronic and atomic physics communities.
This experimental fact creates a serious discrepancy on the value of a fundamental quantity, the proton charge radius. The current situation critically requires a possible theoretical explanation and/or the performance of a new high precision and high accuracy experiment. For the last half year, I have succeeded to create a new collaboration of experts in this field from different universities and developed a new experimental proposal to address this problem in a uniquely designed new magnetic-spectrometer-free (calorimetric) ep-scattering experiment. The proposal has been successfully approved by the recent JLab’s PAC38 in August. We are currently preparing this experiment to perform it either at JLab or at MAMI, Mainz.