LBNL Physics Division Research Progress Meetings

Speaker: Gianpaolo Carosi (LLNL) - Title: Tuning into Dark Matter with the ADMX experiment
2025-11-06 16:00 - 17:00 UTC
Research Progress Meeting
Date: November 6, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Gianpaolo Carosi (LLNL)
Title: Tuning into Dark Matter with the ADMX experiment
Abstract: The primordial axion remains one of the best solutions to both dark matter and the strong-CP problem (or why the neutron doesn’t have a measurable electric-dipole moment). The Axion Dark Matter Experiment (ADMX), which started at Lawrence Livermore National Laboratory in the mid-1990s, is the DOE Flagship search for these particles in the micro-eV mass range. The experiment uses tunable resonant cavities in a large static magnetic field to enhance the conversion of dark matter axions to detectable microwaves in the GHz range. Quantum-limited amplifiers based on superconducting Josephson Junction circuits are critical to allow the search to be sensitive enough to rapidly scan the frequencies where the axion may exist. Here I will describe the detection strategy of ADMX, the progress made so far and outline the potential next phase of the experiment dubbed ADMX-Extended Frequency Range (ADMX-EFR). I will also discuss LLNL’s involvement in the nascent BREAD broadband axion search.
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]
Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Xiaochen Ni (University of Washington) - Title: Development of TopmetalSe: CMOS/aSe Hybrid Detectors for Neutrino Physics
2025-11-20 16:00 - 17:00
Research Progress Meeting
Date: November 20, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Xiaochen Ni (University of Washington)
Title: Development of TopmetalSe: CMOS/aSe Hybrid Detectors for Neutrino Physics
Abstract: The Selena experiment couples an amorphous selenium (aSe) ionization target to a complementary metal–oxide–semiconductor (CMOS) pixel array as an imaging detector for next-generation neutrino physics. Hybrid a-Se/CMOS detectors provide a unique combination of high-Z stopping power, direct charge conversion, and fine-pitch pixel imaging. These properties enable precise reconstruction of ionization tracks with excellent spatial resolution, allowing for low-background measurements with advanced event classification. In this talk, I will present Selena’s capabilities for a neutrinoless double-beta decay search and share the ongoing detector R&D, including the design, fabrication, and characterization of its first prototype pixel array, TopmetalSe, produced in the SkyWater 130 nm open-source CMOS process.
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]
Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Mun Jung Jung (University of Chicago) - Title: Quasielastic–like Interactions of Muon Neutrinos in SBND
2025-11-25 16:00 - 17:00
Research Progress Meeting
Date: November 25, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Mun Jung Jung (University of Chicago)
Title: Quasielastic–like Interactions of Muon Neutrinos in SBND
Abstract: The Short-Baseline Near Detector (SBND), the near detector of the Short-Baseline Neutrino (SBN) program at Fermilab, has completed a successful Run 1, delivering an unprecedented dataset of neutrino-argon interactions. One of the first targets for SBND is the muon neutrino charged-current quasielastic–like channel, the dominant exclusive topology in SBN and a sensitive probe of nuclear effects. In this talk, I’ll present progress toward the first SBND physics results and discuss how the quasielastic-like channel can be studied to test interaction models and lay the foundation for the broader neutrino-nucleus interaction and oscillation physics program at SBND and SBN.
Join Zoom Meeting
https://lbnl.zoom.us/j/95679892182?pwd=[REDACTED]
Meeting ID: 956 7989 2182
Passcode: [REDACTED]

Speaker: Josef Sorenson (University of New Mexico) - Title: Rare B Meson Decays and Precision Timing for Future Colliders
2025-12-02 16:00 - 17:00
Research Progress Meeting
Date: December 2, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Josef Sorenson (University of New Mexico)
Title: Rare B Meson Decays and Precision Timing for Future Colliders
Abstract: Flavor Changing Neutral Currents (FCNCs) are suppressed in the Standard Model (SM). Approximately one in ten billion neutral B mesons decays into pairs of oppositely charged muons. This suppression, combined with the precise theoretical SM predictions, makes this decay a promising channel to search for New Physics. I will present progress towards the latest measurement of the decay of B mesons to muon pairs using the ATLAS Run 2 dataset. The High-Luminosity Large Hadron Collider (HL-LHC) provides an excellent opportunity for measuring this channel, with an expected 3000 fb-1 of p-p collision data. I will present R&D towards precision timing sensors and electronics to deal with the adverse radiation and pileup environments in the HL-LHC and future colliders.
Join Zoom Meeting
https://lbnl.zoom.us/j/95679892182?pwd=[REDACTED]
Meeting ID: 956 7989 2182
Passcode: [REDACTED]

Speaker: Brinden Carlson (University of Florida) - Title: Machine Learning Reconstruction Enhancing SBND's Neutrino Physics Program
2025-12-04 16:00 - 17:00
Research Progress Meeting
Date: December 4, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Brinden Carlson (University of Florida)
Title: Machine Learning Reconstruction Enhancing SBND’s Neutrino Physics Program
Abstract: The Short-Baseline Near Detector (SBND) is a 100-ton Liquid Argon Time Projection Chamber (LArTPC) neutrino detector in the Booster Neutrino Beam at Fermilab, part of the Short-Baseline Neutrino program. I will present my work developing and deploying SPINE, an end-to-end machine learning reconstruction algorithm for neutrino events in LArTPCs. SPINE provides high-quality particle identification and interaction clustering, enabling precision neutrino-argon cross-section measurements and high-quality neutrino selections for oscillation analyses. I will demonstrate SPINE’s impact through a muon neutrino charged current inclusive selection, comparing traditional reconstruction methods to the SPINE-based approach, and discuss how this reconstruction capability supports the SBN program’s physics goals for both cross-section measurements and oscillation analyses.
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]
Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Kehang Bai (University of Oregon) - Title: Exploring the Dark Sector with Low-Mass, Long-Lived Dark Photons and the ATLAS Silicon Tracker
2025-12-09 16:00 - 17:00
Research Progress Meeting
Date: December 9, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Kehang Bai (University of Oregon)
Title: Exploring the Dark Sector with Low-Mass, Long-Lived Dark Photons and the ATLAS Silicon Tracker
Abstract: The rich phenomenology of dark sector models offers exciting opportunities for discovering new physics at the Large Hadron Collider. In this talk, I will present the first ATLAS search for low-mass, long-lived dark photons with displaced vertices in the silicon tracker. This novel signature expands sensitivity to regions of parameter space beyond conventional resonance searches. I will highlight the experimental challenges of searching for long-lived particles in the low-mass regime and emphasize the importance of detailed detector understanding. Finally, I will discuss key aspects of the ATLAS Inner Tracker upgrade for the upcoming high-luminosity era of the Large Hadron Collider.
Join Zoom Meeting
https://lbnl.zoom.us/j/95679892182?pwd=[REDACTED]
Meeting ID: 956 7989 2182
Passcode: [REDACTED]

Speaker: Alexis Mulski (Harvard) - Title: Looking for Unusual Ionization in High-Momentum Particles with the ATLAS Detector at the LHC
2025-12-11 16:00 - 17:00
Research Progress Meeting
Date: December 11, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Alexis Mulski, Harvard University
Title: Looking for Unusual Ionization in High-Momentum Particles with the ATLAS Detector at the LHC
Abstract: What if we could measure the mass of every high momentum charged particle in the ATLAS detector? This talk details the tools in development to make that a reality for tracks associated with a large ionization energy loss (dE/dx). I will place particular emphasis on a new dE/dx measurement from gaseous drift tubes in the ATLAS Muon Spectrometer, born from a detailed understanding of detector hardware and readout electronics. I will present this measurement alongside other Muon-Spectrometer-based tools that aid us in the hunt for long-lived massive and/or di-charged particles, including dedicated reconstruction techniques. I will also discuss the progress of the New Small Wheel upgrade of the ATLAS Muon Spectrometer, and outline the commissioning of the MicroMegas detector trigger in view of the upcoming High-Luminosity LHC era.
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]
Meeting ID: 988 5432 2464

Passcode: [REDACTED]
