Synopsis or brief article reporting on research or teaching highlights taking place within the department.

UConn Physics showing strong at the 2023 APS March Meeting

This year, international conferences have begun to come back into their pre-pandemic form. For the American Physical Society’s annual March Meeting, it was bigger than ever with over 12,000 participants in the world’s largest meeting ever devoted to physics. UConn showed strong as graduate students, postdoctoral fellows, research scientists, and faculty researchers attended the meeting in Las Vegas March 5-10 and showcased their newest results. The team rolled in deep and gave diverse presentations to an international audience on many topics in condensed matter physics, ranging from high-fidelity electronic structure calculations and material modeling, synthesis and characterization of new materials with competing states, advances in industrial science related to advanced manufacturing, synchrotron-based investigations of correlated materials, nanoscale magnetic imaging studies, the development of new cryogenic instrumentation, twistronic effects, vortices in topological materials and circuit-based quantum information science. See you next year!

From left to right: Jacob Pfund, Bochao Xu, Joshua Bedard, Ilya Sochnikov, Gayanath Fernando, Jacob Franklin, Jason Hancock, Donal Sheets, Kaitlin Lyszak
Not pictured: Krishna Joshi, Guang Chen (MSE), Jorge Chavez, Priya Sharma, Alexander Balatsky, Pavel Volkov.

The Milky Way Laboratory Contributes to Art Exhibit at the University of Hartford

Prof. Cara Battersby’s researcMilky Way Lab at UHart Art Exhibith group, the Milky Way Laboratory, was invited to collaborate with Genevieve de Leon, the 2022-23 Koopman Distinguished Chair in the Painting Department at the University of Hartford, for an exhibition focused on the intersection between the Maya calendrical cycles and scientific studies of the cosmos.

From the Milky Way Laboratory, H Perry Hatchfield, Jennifer Wallace, Dani Lipman, and Samantha Brunker contributed scientific figures that are displayed as part of the exhibition.  These figures demonstrate the ongoing research focused on understanding the universe around us through the use of data and scientific analysis.  These figures balance well with Genevieve de Leon’s original, large-scale paintings of constellations in the Maya Zodiac which were created in a methodical, focused way similar to how large-sky surveys are observed.  Genevieve has studied Maya timekeeping extensively, and, through this exhibit, focuses on the intersection of various systems of knowledge.

Additionally, the exhibition includes multimedia work made by indigenous artists in the Native Youth Arts Collective and students at the Hartford Art School which focus on personal connections with the night sky.

Milky Way Lab at UHart Art Exhibit - Orion

Milky Way Lab at UHart Art Exhibit - GalleryMW Lab UHart Art Exhibit - group2

The exhibit, “To Order the Days/Para Ordenar Los Días”, is located in the Donald and Linda Silpe Gallery at the University of Hartford, and will be available from February 23, 2023, to March 25, 2023.

More information can be found at:


Post written by Dr. Samantha Brunker

Prof. Jonathan Trump interviewed by The Conversation about JWST Discoveries

The Conversation interviewed Prof. Jonathan Trump about his recent work with the James Webb Space Telescope (JWST), with an article and podcast interview available at this link. The interview includes discussion of Prof. Trump’s recent journal paper that used spectroscopic observations from JWST to understand the chemical enrichment of galaxies in the early Universe.

Super BigBite Spectrometer Era Begins in Hall A at Jefferson Lab

The first two experiments using the newly constructed collection of apparatus known as the Super BigBite Spectrometer were completed from Oct. 2021-Feb. 2022 in Jefferson Lab’s Experimental Hall A. Data were collected that will determine the neutron’s magnetic form factor (GMN) in a previously unexplored regime of momentum transfer Q2 up to 13.6 (GeV/c)2 with unprecedented precision. Form factor measurements at these energies are sensitive to the structure of the neutron at the sub-femtometer scale, and can resolve features of the neutron’s charge and current distributions at length scales approximately 20 times smaller than the size of a proton. These two completed experiments were the first in a family of precision studies of proton and neutron form factors at high momentum transfer using the SBS apparatus that will occupy the floor of Hall A through 2024. Professor Andrew Puckett’s group plays a leading role in the SBS collaboration (and the group is looking for several new graduate students to work on this exciting and high-impact program!).

Precision high momentum-transfer nucleon form factor measurements are extremely technically challenging, requiring several major innovations in detector technology and high-performance data acquisition and analysis. The GMN set of experiments achieved the first large-scale deployment and operation of Gas Electron Multiplier (GEMs) detectors in the high-luminosity, high-radiation, high-background-rate environment in Hall A. The GEMs were used in this set of experiments for tracking high-energy electrons through the BigBite Spectrometer, which was designed for detecting, tracking, and identifying scattered electrons with large angular and momentum acceptance at high luminosity. Given the large channel count and the high occupancy of the BigBite GEMs (approximately 42,000 readout strips with up to 30-40% of these firing in every triggered event), the SBS GMN run produced 2 petabytes of raw data (or typically about 1 GB/s during beam-on conditions). This is roughly 5 times as much raw data produced in four months of beam time in Hall A as the previous 25 years of Hall A running combined. Charged particle tracking in this extreme high-background environment is also extremely challenging, and UConn developed the software infrastructure and algorithms to do so with high performance and efficiency. The UConn group was one of the most actively involved in the preparation and execution of the experiment, developed the Monte Carlo simulation, event reconstruction and data analysis software, and is now leading the analysis of the collected data using Jefferson Lab’s scientific computing facilities. Two UConn Ph.D. students, Provakar Datta and Sebastian Seeds, will write their doctoral dissertations on the analysis of the SBS GMN dataset.

Projected Q2 coverage and precision of actually collected SBS GMN data
Fig. 1: Projected Q^2 points and expected precision of the data for the neutron’s magnetic form factor obtained from the SBS GMN run during Oct.-Feb., 2021-2022

Figure 1 shows the collected Q^2 points for the extraction of GMN and the projected accuracy based on the data obtained, compared to existing data, selected theoretical models, and the projected Q2 coverage and precision of a measurement in Hall B with similar physics goals, but with larger systematic uncertainties from qualitatively different sources. The measurement of neutron form factors in the SBS-GMN experiment is based on the so-called “Ratio Method”, in which quasi-elastic electron-neutron and electron-proton scattering are measured simultaneously in scattering on a deuterium target (a deuterium nucleus is a weakly bound state of a single proton and a single neutron). By simultaneously detecting electron-neutron and electron-proton coincidence events in elastic kinematics, the ratio of electron-neutron and electron-proton scattering cross sections is determined with very small uncertainties. Combined with the existing knowledge of the electron-proton scattering cross section, the free neutron cross section can be extracted rather precisely.

To carry out this measurement, the SBS Collaboration constructed a large-acceptance Hadron Calorimeter (HCAL) consisting of large modules of many alternating layers of iron and plastic scintillator, which detects both protons and neutrons in the momentum range of these measurements with very high (and nearly identical) efficiencies, leading to much smaller systematic uncertainties compared to previous measurements of this type. Scattered electrons are detected in the BigBite spectrometer, and the scattering angles and momentum of the electron, as well as the location of the interaction vertex, are reconstructed from the precisely measured tracks of ionization they leave in the BigBite GEMs. Under the assumption of elastic scattering on quasi-free protons or neutrons, the scattered neutron or proton must carry all the energy and momentum transferred from the electron in the hard collision, allowing us to predict the location where the protons or neutrons should be detected in HCAL. To identify whether the scattering occurred on a proton or neutron, the scattered protons are given a small vertical deflection by the SBS dipole magnet so that they are well separated from the scattered neutrons by the time they are detected in HCAL.

Figure 2: Difference between the vertical coordinate of the particle detected by the SBS hadron calorimeter and its predicted position from the measured electron kinematics in BigBite, assuming (quasi-) elastic scattering.

Figure 2 shows a comparison between real data from the SBS-GMN experiment obtained at Q2 = 3 GeV2 and the Monte Carlo simulation of the experiment, which includes the full details of the detector geometry and response, and the physics of quasi-elastic scattering of electrons by bound protons and neutrons in the liquid deuterium target, showing the clear separation between protons and neutrons based on magnetic deflection of the protons before they are detected by the SBS Hadron Calorimeter (HCAL), and the low level of background (at this Q2) from processes other than quasi-elastic scattering, demonstrating a very good understanding of the detector at such an early stage of the analysis.


The example event distributions shown below were obtained at an incident electron beam energy of 6 GeV and Q2 = 4.5 GeV2:

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Figure 2 (above) shows the invariant mass distributions for reconstructed electrons in BigBite, from the hydrogen (left) and deuterium (right) targets, before and after applying cuts on the angle between the reconstructed momentum transfer direction and the reconstructed scattering angle of the nucleon (proton or neutron) detected in the SBS hadron calorimeter (HCAL). The hydrogen distribution shows a clear peak at the proton mass corresponding to elastic scattering, and the angular correlation cut removes most of the inelastic background, while keeping most of the events in the elastic proton peak. The deuterium distribution is “smeared” by the Fermi momentum of the bound nucleons in deuterium, and the distributions of events passing the angular correlation cut under the hypothesis that the detected nucleon is a proton (red) or neutron (blue) illustrate the relatively clean selection of quasi-elastic scattering and rejection of most inelastic events using the SBS dipole magnet and hadron calorimeter.

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Figure 3 (above) illustrates the method for nucleon charge identification using the SBS dipole magnet and the SBS hadron calorimeter. The plot shows the difference in vertical position between the detected nucleon at HCAL and the expected position predicted from the reconstructed electron kinematics assuming elastic (or quasi-elastic) scattering. The distributions are shown for hydrogen and deuterium targets for three different SBS magnetic field settings (magnet off, 70% of maximum field, 100% of maximum field). The hydrogen distributions show a single peak corresponding to elastic electron-proton scattering, that moves as the SBS magnetic deflection is varied. The deuterium distribution with field off shows a single nucleon (proton plus neutron) peak, smeared by Fermi motion. The deuterium distributions with SBS field on show a clear separation into proton (deflected) and neutron (undeflected) peaks, with protons undergoing the same average deflection as seen with the hydrogen target.

Prof. Jonathan Trump Interviews about the James Webb Space Telescope

The James Webb Space Telescope released its first science observations on July 12 with much fanfare and excitement across the globe. UConn Physics Professor Jonathan Trump is part of the Cosmic Evolution Early Release Science collaboration that was awarded some of the first observations on the transformative new space telescope.

Prof. Trump was interviewed by several local media outlets, including NPR CT, WILI AM, and the Waterbury Republican-American, about the new James Webb Space Telescope observations and his research goals for the telescope. UConn Today also featured a story about the early JWST observations and scientific findings produced by Prof. Trump’s research collaboration.

Nobel Prize Winner, Professor Donna Strickland , Katzenstein Distinguished Lecturer

The University of Connecticut, Department of Physics, is proud to announce that on September 23, 2022, Professor Donna Strickland of the Department of Physics and Astronomy at the University of Waterloo will be presenting the 2020 Distinguished Katzenstein Lecture. Prof. D. Strickland Prof. Strickland is one of the recipients of the 2018 Nobel Prize in Physics for developing chirped pulse amplification with Gérard Mourou, her PhD supervisor. They published this Nobel-winning research in 1985 when Strickland was a PhD student at the University of Rochester in New York State. Together they paved the way for the most intense laser pulses ever created. The research has several applications today in industry and medicine, including the cutting of a patient’s cornea in laser eye surgery and the machining of small glass parts for use in cell phones.

Prof. Strickland earned a Bachelor in Engineering from McMaster University and a PhD in optics from the University of Rochester. She was a research associate at the National Research Council Canada, a physicist at Lawrence Livermore National Laboratory, and a member of technical staff at Princeton University. In 1997, she joined the University of Waterloo, where her ultrafast laser group develops high-intensity laser systems for nonlinear optics investigations. She is a recipient of a Sloan Research Fellowship, the Ontario Premier’s Research Excellence Award, and a Cottrell Scholar Award. She received the Rochester Distinguished Scholar Award and the Eastman Medal from the University of Rochester.

Prof. Strickland served as the president of the Optical Society (OSA) in 2013 and is a fellow of OSA, the Royal Society of Canada, and SPIE (International Society for Optics and Photonics). She is an honorary fellow of the Canadian Academy of Engineering and the Institute of Physics. She received the Golden Plate Award from the Academy of Achievement, is in the International Women’s Forum Hall of Fame, and holds numerous honorary doctorates.

Prof. Cara Battersby Awarded an NSF CAREER grant

Cara Battersby CAREER AwardProfessor Cara Battersby has been awarded an NSF CAREER grant! “The Faculty Early Career Development (CAREER) Program is a Foundation-wide activity that offers the National Science Foundation’s most prestigious awards in support of early-career faculty who have the potential to serve as academic role models in research and education and to lead advances in the mission of their department or organization.

Prof. Battersby’s CAREER Award is entitled “CAREER: Shining STARs Amidst the Turbulence” and is an ambitious project to complete the first-ever systematic study of turbulence in an extreme environment, the center of our galaxy. Turbulence is poorly understood yet plays a pivotal role in the setting the Initial Mass Function (IMF), which underpins all of modern astrophysics. The results from this research will be brought into under-resourced high school classrooms through lesson plans jointly developed by K-12 teachers and undergraduate students from traditionally under-represented groups. Battersby aims to recruit and retain students from under-represented groups in STEM through a new mentorship program UConn-STARs.

Plates that Helped Map the Universe, Now at UConn

UConn is now home to tools that have played an instrumental role in mapping the universe — 10 large aluminum plates used as part of the Sloan Digital Sky Survey (SDSS). Measuring 32 inches across, one-eighth of an inch thick, and with thousands of tiny holes drilled in them, these plates may not be the type of instruments most people would initially picture; however, they have helped answer important questions about the universe.

Jonathan Trump, associate professor of physics, helped design the final round of plate observations for SDSS, which observed over three million objects in the sky, including stars, galaxies, and supermassive black holes from a telescope in New Mexico.

For more information, see the full UConn Today story here. This story was also featured in May edition of Connecticut Magazine (page 32).

Two Physicists are in Project Daedalus that Focuses on Materials for Aerospace in New $4.7 Million Contract

UConn’s collaboration with the Department of Defense Air Force Research Laboratory (AFRL) is launching a new project. It is titled Multiscale Modeling and Characterization of Metamaterials, Functional Ceramics and Photonics. This is a $4.7 M contract with $1M for Physics. The project’s goal is to explore and advance the understanding of electronic, photonic, magnetic, and multiferroic materials, with future applications in the aerospace industry. Two experimental condensed matter physicists Dr. Menka Jain and Dr. Ilya Sochnikov will contribute to the understanding of magnetic and multiferroic materials. The project supports 4 graduate Research Assistants in the Physics Department and is a unique life-transformative and career-building opportunity for them.

For more information, see UConn Today article

Professor Puckett’s Group Prepares New Measurements of “femtoscopic” Neutron Structure at Jefferson Lab

UConn group on the floor of Hall A
The UConn group on the floor of Hall A during the SBS installation. From left to right: Postdoctoral Research Associate Dr. Eric Fuchey, Professor Andrew Puckett, and Graduate Research Assistants Provakar Datta and Sebastian Seeds. Click the image for a slideshow of additional installation photos and for more details about the experiment.

Professor Andrew Puckett’s research group is currently leading, as part of a collaboration of approximately 100 scientists from approximately 30 US and international institutions, the installation in Jefferson Lab’s Experimental Hall A of the first of a series of planned experiments known as the Super BigBite Spectrometer (SBS) Program, with beam to Hall A tentatively scheduled to begin in early September of 2021. Jefferson Lab, located in Newport News, Virginia, is a national user facility operated by the US Department of Energy, and is the world’s premiere laboratory for imaging the subatomic (and subnuclear) quark-gluon structure of protons, neutrons, and nuclei using its continuous, polarized electron beam. In addition to Professor Puckett, the UConn researchers involved in this effort are Postdoctoral Research Associate Eric Fuchey, and Graduate Research Assistants Provakar Datta and Sebastian Seeds. The first set of experiments in the SBS program, slated to run during Fall 2021, is focused on the measurement of neutron electromagnetic form factors at very large values of the momentum transfer Q2, which essentially probe the spatial distributions of electric charge and magnetism inside the neutron at very small distance scales of order 0.05-0.1 fm (1 fm = one femtometer = 10-15 m = 0.000 000 000 000 001 m), approximately 10-20 times smaller than the size of the proton and approximately 1 million times smaller than the size of a typical atom.

Electrons from Jefferson Lab’s Continuous Electron Beam Accelerator Facility (CEBAF), with energies of up to 10 GeV (=10 billion electron-volts), will scatter elastically from protons and neutrons in a liquid deuterium target in Hall A. Scattered electrons will be detected in the BigBite Spectrometer, located on the left side of the beam, while the high-energy protons and neutrons recoiling from the “hard” collisions with the beam electrons will be detected in the SBS by the newly constructed Hadron Calorimeter (HCAL), located on the right side of the beam. The SBS dipole magnet will provide a small vertical deflection of the scattered protons, which allows HCAL to distinguish them from scattered neutrons, which are undeflected by the magnetic field, but produce otherwise identical signals in HCAL.

The first group of SBS experiments, collectively known as the “GMN run group”, will answer several important questions about the “femtoscopic” structure of the neutron, including:

  • What is the behavior of the neutron’s magnetic form factor at large momentum transfers? The SBS experiment will dramatically expand the Q2 reach of neutron magnetic form factor data compared to all previously existing measurements, from approximately 4 –> 14 (GeV/c)2. See original experiment proposal here.
  • How is the charge and magnetism of the proton shared among its “up” and “down” quark constituents as a function of Q2? The proton magnetic form factor has been measured over a much wider range of Q2 than the neutron, and combined proton and neutron measurements can be used to disentangle the contributions of “up” and “down” quarks (and diquark correlations) to the proton’s structure, under the assumption of charge symmetry of the strong interactions (see, e.g., https://inspirehep.net/literature/1812076)
  • How important and/or significant is the contribution of two-photon-exchange to elastic electron-neutron scattering? The first SBS experiment group will perform measurements of the electric/magnetic form factor ratio for the neutron using two different techniques known as “Rosenbluth Separation” and “Polarization Transfer”, at a Q2 where these two techniques have shown significant disagreement for the proton. Both measurements will be the first of their kind for the neutron at such large Q2 values (see, e.g., Polarization Transfer Proposal and Rosenbluth Separation Proposal)

The GMN run group will start in early September and run through the fall of 2021. The broader SBS program will continue in Hall A through at least 2023, and will drastically improve our understanding of the femtoscopic quark-gluon structure of protons, neutrons, and atomic nuclei. Professor Puckett’s research in the SBS and Hall A Collaborations is supported by the US Department of Energy, Office of Science, Office of Nuclear Physics. Stay tuned!