Events at Physics |
Events During the Week of October 18th through October 25th, 2026
Monday, October 19th, 2026
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Title to be announced
- Time: 12:00 pm - 1:00 pm
- Place: 2241 Chamberlin Hall
- Speaker: Auna Moser, General Atomics
- Host: Vladimir Zhdankin
Tuesday, October 20th, 2026
- Graduate Program Event
- Search for new physics in events with top quark pairs and missing transverse momentum with the CMS Experiment
- Time: 3:00 pm - 5:00 pm
- Place: Chamberlin 5280
- Speaker: Ameya Thete
- Abstract: This talk presents an ongoing model-independent search for beyond-the-Standard Model (BSM) physics in events with a top quark pair and missing transverse momentum, where the top quark pair is reconstructed in fully hadronic final states with multiple jets. The search is performed in proton-proton collision data recorded by the CMS Experiment at a centre-of-mass energy of 13.6 TeV during Run 3 of the Large Hadron Collider. Only the resolved topology is considered, in which the decay products of each top quark can be reconstructed as separate jets. Anomalous events are identified with a multivariate score built from state-of-the-art anomaly detection methods, which avoids assuming a specific signal hypothesis. Major backgrounds like QCD multijet production are estimated with data-driven techniques to model the Standard Model expectation accurately. A plan is presented to interpret the results across a broad range of BSM scenarios, including simplified dark matter models and exotic invisible decays of the Higgs boson.
- Host: Tulika Bose
Wednesday, October 21st, 2026
- Preliminary Exam
- Probing Element Specific Ultrafast Carrier and Spin Dynamics in Quantum and Magnetic Materials using X-FAST Instrument
- Time: 11:00 am - 1:00 pm
- Place: Chamberlin 5280
- Speaker: Aakankshya Mishra
- Abstract: Emerging quantum and magnetic materials host strongly coupled electronic, spin, and lattice degrees of freedom that can evolve on femtosecond timescales, making their nonequilibrium behavior important for understanding and ultimately controlling material properties relevant to future information and quantum technologies. This work uses X-ray Femtosecond Absorption Spectroscopy Tabletop (X-FAST), a laboratory-based extreme-ultraviolet (XUV) transient absorption instrument, to investigate these ultrafast processes with element specificity. X-FAST employs high-harmonic generation (HHG) to produce femtosecond XUV pulses that probe element-specific core-to-valence transitions following excitation by an ultrafast optical pump. This preliminary examination will introduce the motivation for studying emerging quantum and magnetic materials, the fundamentals and development of HHG-based tabletop XUV sources, and the experimental methodology and optimization of the X-FAST instrument. The capabilities of X-FAST will be demonstrated through measurements of 2H-MoTe₂ as a benchmark system and through studies of MnPtGa, where element-specific transient absorption provides insight into photoinduced carrier redistribution and its connection to the material’s magnetic electronic structure. In addition, the development and integration of a cryogenic sample environment will extend X-FAST toward temperature-dependent measurements, enabling the separation of electronic, magnetic, and lattice contributions and the investigation of phase-dependent ultrafast dynamics. Finally, future directions will focus on expanding the range of quantum and magnetic materials studied with X-FAST and advancing the instrument toward a versatile platform for probing and understanding nonequilibrium material behavior across ultrafast timescales and variable temperatures.
- Host: Uwe Bergmann
- Theory Seminar (High Energy/Cosmology)
- Entanglement Limits on Coherent Enhancement
- Time: 1:00 pm - 2:30 pm
- Place: Chamberlin 5280
- Speaker: Zach Bogorad, Fermilab
- Abstract: Coherent enhancement is a powerful mechanism for improving the sensitivity of a wide range of detectors, but its practical use is often limited by the difficulty of preparing the required quantum states. In this talk, I will show that this difficulty has a fundamental origin: coherent enhancement is quantitatively constrained by entanglement. I will present general bounds on how the strength of coherent effects can scale with system size, as a function of the single-mode entanglement entropy of the detector. These bounds smoothly interpolate between the incoherent and fully coherent regimes, and apply both to parameter-estimation problems and to scattering processes. I will discuss these results from two complementary perspectives: First, they appear as bounds on the quantum Fisher information of many-body states, which translate directly into limits on parameter sensitivity via the quantum Cramér–Rao bound. Second, they can be interpreted as limits on a class of scattering cross sections, leading to predictions for how minimum detectable interaction strengths scale with target size. Together, these results provide a unified view of coherent enhancement in metrology and scattering experiments, and motivate the development of new techniques for generating entangled detector states.
- Host: Josh Foster
Thursday, October 22nd, 2026
- R. G. Herb Condensed Matter Seminar
- Update on UTe2
- Time: 10:00 am
- Place: 5310 Chamberlin Hall
- Speaker: Daniel Shaffer , APS
- Host: Alex Levchenko
- Astronomy Colloquium
- Probing Cosmic Plasmas from Sub-AU to Gigaparsec Scales
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Stella Ocker, Brinson Prize Postdoctoral Fellow, California Institute of Technology
- Abstract: Most of the ordinary matter in the universe takes the form of diffuse ionized gas, or plasma. Characterizing the full distribution of this plasma is critical to understanding how the universe forms its main structures. In this talk, I will discuss recent breakthroughs in our efforts to resolve the distribution of cosmic plasmas across a vast range of spatial scales, primarily based on observations of pulsars and fast radio bursts (FRBs). These observations are distinct in that they trace plasma densities on galactic and intergalactic scales, as well as sub-au plasma fluctuations. I will present the NE2025 Galactic electron density model, and demonstrate how an up-to-date understanding of the Milky Way’s turbulent ionized gas distribution will reveal extremely diffuse plasmas around and between galaxies, as well as enabling a sharp-eyed view of FRBs’ local environments. Implications for key surveys of the late 2020's, including the Schmidt Observatory System's Deep Synoptic Array, will be discussed
- Host: Snezana Stanimirovic
Friday, October 23rd, 2026
- Physics Department Colloquium
- Title to be announced
- Time: 3:30 pm - 4:30 pm
- Place: Chamberlin 2241 -
- Host: Alex Levchenko