Events During the Week of March 1st through March 8th, 2026
Sunday, March 1st, 2026
- Graduate Program Event
- Ice Skating Social
- Time: 1:30 pm - 3:00 pm
- Place: Bakke Recreation and Wellbeing Center: Sub-Zero Ice Rink (1976 Observatory Drive | Madison, WI 53706)
- Abstract: The Physics Department will be hosting an ice skating social on Sunday, March 1, 1:30pm-3:00pm at the Sub-Zero Ice Rink in Bakke Recreation & Wellbeing Center.
- Host: Alice Kwok
Monday, March 2nd, 2026
- Plasma Physics (Physics/ECE/NE 922) Seminar
- The Case for Using Liquid Lithium for Low Recycling Fusion Reactor Operations and Why the Sun Works!
- Time: 12:00 pm - 1:00 pm
- Place: Engineering Hall 1227
- Speaker: Dr. Daniel Andruczyk, University of Illinois at Urbanan-Champaign
- Abstract: Why does the Sun work? This is an important and nuanced question and the answer potentially tells us how we need to run a fusion reactor. But in doing so it exposes one of the main issues in fusion. To truly achieve a steady state working fusion power plant there is a major hurdle that needs to be overcome, plasma material interactions (PMI). The materials used to build these devices are extremely important. Traditionally solid materials (tungsten, molybdenum, carbon, etc.) have been used but encounter many issues when exposed to the high heat fluxes in the divertor region, which can reach 40 MWm-2 or more in some cases. Interactions with energetic ions, neutrals and neutrons can cause surface morphology changes (DPA, transmutation, fuzz, bubbles, blisters), ejection of material into the plasma, recycling of cold neutral gas back into the plasma and fuel depletion through implantation into the material. It turns out there may be a solution, liquid metals, and in particular liquid lithium (Li), which offer several solutions to many of the issues solid materials face. There are still technological challenges using liquid Li, and these are all under investigation and development. This talk will focus on PMI challenges and how Li can solve many of these issues. Why does the Sun work? … the answer to come!
- Host: Stephanie Diem
- Theory Seminar (High Energy/Cosmology)
- BSM Light Mediator Opportunities from On-Going SM Experiments
- Time: 1:00 pm - 2:30 pm
- Place: Chamberlin 5280
- Speaker: Isaac R. Wang, Fermilab
- Abstract: Light mediators are a type of well-motivated particles. Their masses and couplings can vary in different theories. In this talk, I investigate several new experiments mainly motivated by SM that are sensitive to BSM light mediators, with the example of dark photon and neutrino self-interaction mediator. We found that the MUonE, Hyper-K, IceCube, and GRAND experiments are sensitive to these mediators in a wide range of parameter space.
- Host: Joshua Foster
Tuesday, March 3rd, 2026
- No events scheduled
Wednesday, March 4th, 2026
- Thesis Defense
- Hunting heavy di-Higgs resonances in bbtautau final states and commissioning of GPUs for the CMS High-Level Trigger.
- Time: 1:00 pm - 3:00 pm
- Place: Chamberlin 5280
- Speaker: Ganesh Parida
- Abstract: This dissertation presents a search for massive, narrow-width resonances decaying to pairs of Higgs bosons in the bb̄ττ final state, where one Higgs boson decays into a pair of bottom quarks and the other into a pair of tau leptons (X → HH → bb̄ττ). Such resonances are predicted by beyond-the-standard-model theories, which aim to address the shortcomings of our current understanding of fundamental particles and their interactions. The search uses proton–proton collision data at a center-of-mass energy of 13 TeV recorded by the Compact Muon Solenoid (CMS) experiment during 2016–2018, corresponding to an integrated luminosity of 138 fb⁻¹, and targets resonances in the mass range of 1–4.5 TeV. The analysis uses a single large jet to reconstruct the H → bb̄ decay, while the H → ττ decay products can either be contained within a single large jet or appear as two isolated tau leptons. The reconstruction and identification of physics objects are enhanced using advanced machine learning techniques, including a graph convolutional neural network for merged bb̄ jets and a convolutional neural network specifically designed for this search to identify merged ττ decays. Upper limits at the 95% confidence level are set on the production cross section for resonant HH production in the mass range considered, with this analysis providing the most sensitive limits to date on X → HH → bb̄ττ decays for masses above 1.4 TeV. The second component of the thesis describes the commissioning and validation of graphics processing unit (GPU)-based reconstruction at the CMS high-level trigger for Run 3 data-taking. To address increasing computational demands arising from higher instantaneous luminosity and greater event complexity, reconstruction algorithms for the hadron calorimeter, electromagnetic calorimeter, and pixel tracker were offloaded to GPUs to take advantage of parallel processing wherever feasible. Dedicated physics validation was required to ensure that the GPU-offloaded algorithms produce physics results consistent with the central processing unit (CPU)-based reconstruction. The final trigger configuration seamlessly utilizes GPU hardware when available while maintaining backward compatibility with CPU-only configuration, establishing a foundation for meeting the computational challenges of the high-luminosity LHC era.
- Host: Tulika Bose
Thursday, March 5th, 2026
- R. G. Herb Condensed Matter Seminar
- Dynamical breaking of inversion symmetry, strong second harmonic generation, and ferroelectricity with nonlinear phonons
- Time: 10:00 am - 11:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Egor Kiselev , MPIPKS
- Abstract: I will show how crystalline inversion symmetry can be dynamically broken by optical phonons with generic, hardening Kerr-like non-linearities. The symmetry-broken state is reached through a dynamical phase transition that can be accessed by driving close to half the phonon resonance. After going through an instability, the system settles to a steady state with inversion-symmetry breaking phonon trajectories and strong second harmonic generation. The time averaged positions of the atoms are displaced relative to equilibrium, resulting in a rectification of the driving signal. This leads to a dynamical dipolar, ferroelectric response that shows features like hysteresis and memory effects, known from equilibrium ferroelectrics.
- Host: Elio König
- Astronomy Colloquium
- TBD
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Director Julianne Dalcanton, Flatiron Institute/CCA
- Abstract: TBD
- Host: Michael Maseda
Friday, March 6th, 2026
- Physics Department Colloquium
- Title to be announced
- Time: 3:30 pm - 4:30 pm
- Place: Chamberlin 2241
- Speaker: David B. Kaplan, University of Washington
- Host: Daniel Chung