Events at Physics |
Events During the Week of April 19th through April 26th, 2026
Monday, April 20th, 2026
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Effects of magnetic geometry and neutrals in gyrokinetic simulations of magnetized boundary plasmas
- Time: 12:00 pm - 1:00 pm
- Place: Engineering Hall - 1227
- Speaker: Dr. Tess Bernard, General Atomics
- Abstract: Successful fusion pilot plant (FPP) design hinges upon the ability to predict and control exhaust conditions to maximize the lifetime of plasma-facing components. This work describes a pathway toward high-fidelity, first-principles simulations with predictive capabilities for plasma particle fueling and detachment. It presents the coupling of a continuum full-f gyrokinetic turbulence model with atomic neutral models, using the Gkeyll code. To investigate how neutral interactions and plasma shaping fundamentally affect edge turbulent transport, we carry out simulations of DIII-D inner-wall-limited (IWL) plasmas. We specifically consider negative triangularity (NT) plasmas, which exhibit robust confinement properties without the presence of disruptive edge localized modes (ELMs). Results demonstrate good agreement with experimental data, with neutral interactions providing important particle fueling and heat loss channels. Our analysis reveals key differences in the shear flow and turbulent fluctuations that contribute to improved confinement properties in NT.
- Host: Stephanie J. Diem
- Theory Seminar (High Energy/Cosmology)
- A data-driven prediction for the primordial deuterium abundance
- Time: 1:00 pm - 2:30 pm
- Place: Chamberlin 5280
- Speaker: Hongwan Liu, Boston U.
- Abstract: The primordial deuterium abundance D/H from Big Bang Nucleosynthesis (BBN) is one of the most powerful probes of ΛCDM cosmology and its extensions. I will present a novel, fully data-driven method for predicting D/H using Gaussian processes, validated with Monte Carlo tests that confirm negligible bias and accurate coverage of the resulting uncertainties. Applying the same Monte Carlo framework to polynomial fitting methods commonly used in the literature, we find that these systematically overestimate D/H. Assuming baryon abundances from CMB measurements, our predictions are approximately 2σ discrepant with observations of the primordial D/H. Event recording:
- Host: Joshua Foster
- Graduate Program Event
- A search for dark matter recoiling from the standard model Higgs boson using the CMS experiment
- Time: 1:00 pm - 3:00 pm
- Place: Chamberlin 3290 (NOTE UPDATED LOCATION)
- Speaker: Shivani Lomte
- Abstract: Astrophysical evidence supports the existence of dark matter based on its gravitational interaction. Astrophysical evidence also points to that dark matter interacts at most very weakly with the standard model particles. The only purely weakly interacting particles in the standard model are neutrinos, which have too low a mass to be the dark matter candidates. Therefore, there is compelling motivation for physics beyond the standard model which contains weakly interacting massive particles. Many beyond the standard model theories predict the existence of dark matter particle candidates that can be produced and detected at high energy colliders, driving experimental searches at the CERN LHC. This thesis presents a search for dark matter particles produced in association with a Higgs boson in proton-proton collisions at 13 TeV. The data, collected with the CMS detector at the LHC, correspond to an integrated luminosity of 101 /fb. Higgs decay to a bottom quark-antiquark pair is reconstructed to identify events of interest. The analysis is performed in exclusive categories targeting both Lorentz-boosted (merged) and resolved b-pair topologies, covering a wide range of Higgs boson transverse momentum. This analysis looks for statistically significant deviations from the standard model predictions, either enhancements in specific kinematic regions or a bump in the b-pair invariant mass distribution. The observed data agree with the standard model background predictions. Constraints are placed on dark matter models predicting new particles or interactions, such as those in the simplified frameworks of baryonic-Z' and 2HDM+a. A statistical combination is made with a previous search using data collected in 2016 and corresponding to an integrated luminosity of 35.9 /fb. Upper limits at 95% confidence level are set on the production cross section for these models. These results improve upon the previously existing LHC limits owing to the larger integrated luminosity and improved identification of h-->bb decay. Potential improvements from an ongoing CMS search using the Run-3 data are discussed, along with the future prospects at a high energy muon collider.
- Host: Sridhara Dasu
Tuesday, April 21st, 2026
- No events scheduled
Wednesday, April 22nd, 2026
- Board of Visitors Meeting
- Time: 8:00 am - 5:00 pm
- Place: B343 Sterling
- Speaker: Various
- Host: Kevin Black
Thursday, April 23rd, 2026
- R. G. Herb Condensed Matter Seminar
- Superconducting control for scaled quantum systems, and strongly-coupled two-level defects
- Time: 10:00 am - 6:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Brad Christensen, Northrop Grumman
- Abstract: Northrop Grumman has developed Reciprocal Quantum Logic (RQL), an extremely energy efficient superconducting logic family. We will describe how we use it to perform microwave-free universal control of superconducting dual-rail qubits. We will then discuss how we characterize and mitigate a source of infidelity: strongly-coupled two-level systems located in and near the junction.
- Host: Robert McDermott
- Astronomy Colloquium
- The Virtual Planetary Laboratory and the Search for Signs of Life on Exoplanets
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Victoria Meadows, Senior Research Scientist, SETI Institute
- Abstract: The Virtual Planetary Laboratory is a massively interdisciplinary research group that has been working since 2001 to put a strong scientific foundation under the search for signs of life on exoplanets. This exciting quest was identified as a high priority in both the Astro2020 and planetary science decadal reviews, and it is a key science driver for NASA’s next flagship space telescope, the Habitable Worlds Observatory. To search for life on an exoplanet we must look for potentially-detectable global impacts of life on its planetary environment, such as atmospheric gases released by metabolic processes. However, these biosignatures must be interpreted in the context of their planetary environment, to rule out planetary processes such as volcanism and photochemistry that may enhance, destroy or mimic a targeted biosignature. Consequently, to determine if a biosignature is more or less likely to be due to life, a broad range of information on planetary and stellar properties and processes must also be acquired. Depending on wavelength range, size, and whether ground- or space-based, different telescopes will be capable of advancing the search for life in different ways, ultimately providing synergistic pieces of a much larger puzzle. In this talk I will describe the potential capabilities for biosignature searches using high-resolution spectroscopy with ground-based telescopes and low resolution spectroscopy with JWST, and I will place these opportunities in the context of what might be possible with space-based telescopes over the next two decades.
- Host: Joint colloquium with WiCOR
Friday, April 24th, 2026
- Black and Brown in Physics
- BBiP Arab-American + APIDA Heritage Month Event
- Time: 1:00 pm - 2:00 pm
- Place: Chamberlin 2135
- Abstract: The Black and Brown in Physics (BBiP) student organization would like to invite you to our next Heritage Month Event (in honor of April being Arab American Heritage month, and May being Asian Pacific Islander Desi American Heritage / APIDA month) on Friday April 24th at 1 PM in Chamberlin 2135. This time we have the privilege of inviting Faizah Siddique (BBiP’s very own secretary!) to give a 20-minute talk about Bangladeshi history, culture, and heritage followed by some time for Q&As. In addition to the talk, we will also have a short presentation highlighting the contributions that Arab physicists have made to the scientific community. We will also spend some time toward the end to talk about our upcoming executive member elections and give folks some time to apply/self-nominate themselves for a BBiP executive position for the next 2026-27 academic year (if you are interested in doing so), and maybe also play a fun singing game!
We will be broadcasting the talk over Zoom (see below for link) for those unable to make it to the event in-person.
Zoom Link:
We will be catering lunch from Kanto Fiesta (Filipino food), and Taza (Mediterranean food). We kindly ask that if you are planning on attending the lunch in-person that you stay for the talks as well. Our speakers put a lot of thought and time into making their presentations, and it’s important that we honor that by attending both parts of the event. - Host: Black and Brown in Physics (BBiP)
- Physics Department Colloquium
- The attosecond-Ångstrom frontier at x-ray free-electron lasers
- Time: 3:30 pm - 4:30 pm
- Place: Chamberlin 2241
- Speaker: Linda Young, ANL
- Abstract: The recent advent of x-ray free-electron lasers (XFELs) enables researchers to watch matter move on the natural time and length scales of electronic and atomic motion. Not only are freeze-frame snapshots with sub-femtosecond exposure times possible, these accelerator-based x-ray laser sources provide coherent radiation of sufficient intensity to perform nonlinear spectroscopy with x-rays. Within this context I will discuss two recent projects from our group, the realization of super-resolution stimulated x-ray Raman spectroscopy and attosecond-pump/attosecond-probe spectroscopy of liquid water, and some opportunities for future studies to understand x-ray interactions with matter.
- Host: Uwe Bergmann