Colloquium Schedule Fall 2026
Monday, August 24, 2026
Speaker: Jason Alicea (California Institute of Technology)
Title: Measurement-altered quantum matter
Abstract: In the study of quantum matter, measurements have traditionally been viewed as a means of learning about a system. Measurements can, nevertheless, play a more active role — generating novel quantum phenomena that may be difficult or impossible to realize in measurement-free settings. As an interesting example, I will discuss how measurements can dramatically alter universal properties of quantum systems tuned to a phase transition. I will also highlight a path to experimental realization in analog quantum simulators based on Rydberg atom arrays. Finally, I will describe how these ideas inform optimization of quantum teleportation protocols against imperfections — establishing a long-term quantum science application of “measurement-altered quantum criticality.
Host: Adarsh Patri
Monday, August 31, 2026
Speakers: Graduate Student Presentations by Addison Arcuri, Henry Howard, Nazmus Sayadat Ifat, Joshua Miller, Mayank Pal, Kajal Rabari, Suman Shrestha, Joseph Torsiello (Temple University)
Title: Third Physics Department Research Symposium / Individual titles are shown below
Abstract: Individual abstracts are shown below
Host: Martha Constantinou
Presentation 1:
Møller Polarimetry Improvements for the MOLLER Experiment at Jefferson Lab
Arcuri, Addison; Graduate Student
Advisor: Jim Napolitano
Abstract: The upcoming MOLLER Experiment at Thomas Jefferson National Accelerator Facility will determine the weak mixing angle through measurement of the parity-violating asymmetry (A_PV) in longitudinally polarized Møller scattering. Our error goal is 0.8 ppb on an ≈ 33 ppb asymmetry, for a fractional uncertainty of 2.4% (2.1% statistical and 1.1% systematic). One of the largest systematic uncertainties is the 0.4% allotted for polarimetry.
Meeting this strict requirement necessitates improvements to the Møller polarimeter. Dedicated studies of the existing data acquisition system (DAQ) have resulted in improved accidental coincidence and dead time corrections. A new and more rigorous model for accidentals was developed, and a measurement of dead time constants yielded values approximately twice those previously reported. In addition, a new FADC-based DAQ is under development, requiring new analysis tools and DAQ studies of its own.
Presentation 2:
Predicting Water XAS Using a Minimal Set of Descriptors
Howard, Henry; Graduate Student
Advisor: Xifan Wu
Abstract: Oxygen K-edge X-ray absorption spectroscopy (XAS) is an experimental probe of local structure, with liquid water and its amorphous and crystalline ices giving markedly different spectra. From calculated spectra, we show that two descriptors, a soft hydrogen-bond count plus a graph-theory measure of connectivity, order the phases structurally. Conditioning a generative adversarial autoencoder on these two descriptors reproduces the ensemble-averaged spectra. Our model extrapolates to Ice VIII, held out from training, reproducing its spectrum qualitatively even though Ice VIII sits at the maximum of one descriptor (fully hydrogen-bonded) and the minimum of the other (disconnected), a combination absent from our training data. This suggests the model learned two coordinates that govern the XAS lineshape.
Presentation 3:
Progress on STT Digitization and Time-to-Distance Calibration for the MUSE Experiment
Ifat, Nazmus Sayadat; Graduate Student
Advisor: Nikos Sparveris
Abstract: The MUon Scattering Experiment (MUSE) at the Paul Scherrer Institute (PSI) is designed to simultaneously measure elastic electron-proton and muon-proton scattering at low momentum transfer, probing the proton radius puzzle through a direct test of lepton universality. A key element of the MUSE detector is the Straw Tube Tracker (STT), which reconstructs charged particle trajectories after scattering from the liquid hydrogen target.
Calibrating the STT and understanding its performance is critical to achieving the design resolution required for precision cross-section measurement and radius extraction.
This talk presents progress on two complementary aspects of the STT analysis pipeline. STT digitization studies improve the MUSE Geant4 simulation by modeling detector response more realistically at the signal and hit level. In parallel, time-to-distance (TTD) calibration determines the relationship between drift time and drift distance within each straw to improve position reconstruction. Together, these efforts validate the STT reconstruction chain and reduce tracking-related systematic uncertainties.
This work has been supported by the US Department of Energy Office of Science, Office of Nuclear Physics under Contract No. DE-SC0016577. The MUSE experiment is supported by the Department of Energy, NSF, PSI, and the US-Israel Binational Science Foundation.
Presentation 4:
Vector PDF Mellin Moments of the Pion and Kaon PDF from Lattice QCD
Miller, Joshua; Graduate Student
Advisor: Martha Constantinou
Abstract: Utilizing non-local operators of a boosted hadron have allowed us to extract the x-dependence of parton distribution functions (PDFs) through methods such as short distance factorization (SDF). Within PDFs is information on fundamental hadronic properties, such as the fraction of the hadron momentum carried by quarks, which is stored in the Mellin moments. From SDF, we extract these moments, which are used to reconstruct the PDF. We study the pion and kaon, as they are the lightest hadron and SU(3) symmetry counterpart, respectively. By studying both hadrons, we compare the up and strange quark contributions, study SU(3) symmetry breaking, as well as PDF reconstruction. In this work, we extract moments up to NNLO accuracy and utilize DGLAP evolution to study systematics associated with perturbative matching. We utilize an Nf = 2+1+1 ensemble of twisted mass fermions with a clover improvement at a pion mass of 260 MeV.
Presentation 5:
Measurement of W+/W- cross-sections and their ratio
Pal, Mayank; Graduate Student
Advisor: Bernd Surrow
Abstract The W production in unpolarized pp collisions is sensitive to the sea quark distributions. The charge sign of the W boson tagged by the decay lepton provides natural separation between the sea dbar and ubar quark distributions. By taking the cross-section ratio, σ(pp → W+ X)/σ(pp → W− X), the sea quark distributions and their ratio, dbar/ubar, can be measured. Here I will present my results for unpolarized pp → W± X cross sections and cross-section ratios via leptonic decay channels W → eν at a center of mass energy of √ s = 508 GeV using 2022 data from STAR at an integrated luminosity of 400 pb⁻¹.
Presentation 6:
Probing Lipid Membrane Phase Transitions with Second-Harmonic Light Scattering
Rabari, Kajal; Graduate Student
Advisor: Dr. Hai-Lung Dai
Abstract: Lipid membranes undergo temperature-dependent structural changes that strongly influence their physical properties. Here, we use second-harmonic scattering (SHS), a nonlinear optical technique sensitive to molecular ordering at interfaces, to probe the gel-to-fluid phase transition of dimyristoylphosphatidylcholine (DMPC) lipid membranes. Temperature-dependent SHS measurements are used to monitor changes in the membrane's molecular organization as it undergoes its phase transition. By analyzing the SHS response across the transition region, we characterize the temperature dependence of membrane ordering and identify signatures associated with changes in lipid packing and dynamics. This approach provides an optical perspective on membrane phase behavior and demonstrates how nonlinear optical measurements can be used to investigate thermally driven changes in soft condensed matter systems. The results also provide a foundation for studying how membrane composition and additives such as cholesterol modify lipid phase transitions and membrane properties.
Presentation 7:
Studies of Nuclear SIDIS Observables with CLAS12 at Jefferson Lab
Shrestha, Suman; Graduate Student
Advisor: Nikos Sparveris
Abstract: Semi-Inclusive Deep Inelastic Scattering (SIDIS) process enables a study of the three dimensional structure of nucleons through transverse momentum-dependent parton distribution (TMDs). Extending SIDIS measurements to nuclear targets provides an opportunity to investigate nuclear effects on parton dynamics and hadronization. This work is based on the data collected by the CLAS Collaboration at Jefferson Lab in Fall 2023. The measurement has been performed with various targets including liquid deuterium, and solid carbon, copper, and tin targets. In this talk, we will present preliminary studies of nuclear SIDIS observables with a focus on π+ production. This work has been supported by the US Department of Energy Office of Science, Office of Nuclear Physics under Contract No. DE-SC0016577.
Presentation 8:
Pion and kaon x-dependent GPDs from Lattice QCD
Torsiello, Joseph; Graduate Student
Advisor: Martha Constantinou
Abstract: We present a calculation of the x dependence of unpolarized quark GPDs for the pion and kaon on an Nf=2+1+1 ensemble of maximally twisted-mass fermions with a clover term, with lattice volume 32³ × 64, lattice spacing a=0.0934 fm, and pion mass m_π=260 MeV. The matrix elements contain boosted hadrons coupled to nonlocal operators and are computed for momentum boosts up to 2 GeV and momentum-transfer square up to about 2.5 GeV². The data are analyzed using both the large-momentum effective theory and short-distance factorization frameworks, providing complementary information. We investigate the dependence of the results on the hadron momentum, momentum transfer, and reconstruction procedure.
Monday, September 7, 2026 - Labor Day
Monday, September 14, 2026
Speaker: Jim Napolitano (Temple University)
Title: The MOLLER Experiment: High Energy Physics at Low Energies
Abstract: Nature violates parity symmetry. Discovered almost 70 years ago, this phenomenon implies that the universe is “left-handed.” Although we have a very successful theory, the Standard Model of Particle Physics, which agrees with scores of experimental tests, it includes parity violation in an ad hoc way. There are hints that the Standard Model should break down at very high energies, restoring parity symmetry. There are viable conjectures for how that might come about, and much of High Energy Physics tries to reach the energy scales where this breakdown might occur.
This talk describes a different approach, trading very high-energy interactions for extremely precise measurements at lower energies. The MOLLER experiment at Jefferson Lab will measure parity violation in electron-electron scattering for which the Standard Model makes a precise prediction. Disagreement between experiment and theory at this level would indicate “new physics” at energies beyond the reach of current high-energy collider facilities. After introducing the key concepts, I will describe the challenges of making this ultra-precise measurement and the timeline for executing the experiment.
Host: Colloquium Committee
Monday, September 21, 2026
Speaker: Will Detmold (MIT)
Title: The Secret Life of Quarks
Abstract: In this talk, I will explore the fascinating world of quarks and gluons and how their dynamics define the structure of hadrons such as the proton and all matter that is built from them.
Host: Andreas Metz
Monday, September 28, 2026
Speaker: Bill Zajc (Columbia University)
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Host: Jim Napolitano
Monday, October 5, 2026
Speaker: Long Lu (MIT)
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Host: Adarsh Patri
Monday, October 12, 2026
Speaker: Aaron Sternbach (The University of Maryland, College Park)
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Host: Alex Gray
Monday, October 19, 2026
Speaker: Xiaoshan Xu (University of Nebraska-Lincoln)
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Host: Xifan Wu
Monday, October 26, 2026
Speaker: Ryan Dahn (Physics Today, College Park, MD)
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Host: Jim Napolitano
Monday, November 2, 2026
Speaker: Yuri Kovchegov (The Ohio State University)
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Host: Farid Salazar
Monday, November 9, 2026
Speaker: Reshmi Mukherjee (Columbia University)
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Host: Priyadarshini Bangale
Monday, November 16, 2026
Speaker: Zhongbo Kang (University of California, Los Angeles)
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Host: Farid Salazar
Monday, November 23, 2026 - Thanksgiving Break
Monday, November 30, 2026
Speaker: Ryan J. Szukalo (Princeton University and University of Calgary)
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Host: Xifan Wu
Monday, December 7, 2026
Speaker: Bingqing Cheng (University of California, Berkeley)
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Host: Xifan Wu