LBNL Physics Division Research Progress Meetings

Speaker: Brenda Frye (University of Arizona) - Title: Measuring the Hubble-Lemaitre Constant with James Webb Space Telescope Observations of the Lensed Supernova H0pe
2024-06-13 16:00 - 17:00 UTC
Research Progress Meeting
Date: June 13, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Brenda Frye (University of Arizona)
Title: Measuring the Hubble-Lemaitre Constant with James Webb Space Telescope Observations of the Lensed Supernova H0pe
Abstract: A review of cluster lensing in the first two years of James Webb Space Telescope (JWST) observations is presented, focussing on the JWST Guaranteed Time Observations (GTO) program the Prime Extragalactic Areas for Reionization and Lensing Science (PEARLS). These observations range from the spectacle of JWST “first light” images of the distant universe to dense galaxy cluster fields that uncovered unprecedented numbers of giant arcs and image multiplicities. A point-source was discovered in the PEARLS image of the galaxy cluster field PLCK G165.7+67.0 (G165) that is bright and appears in three different locations as a result of strong lensing. Additional JWST observations confirmed this source to be a normal Type Ia supernova (SN) at a redshift of 1.783 that we call “SN H0pe,” making it one of the highest redshift standard candles. In a blinded approach, seven independent lens models were constructed, and time delays between the images were measured in two ways, off of: (1) the light curve, and (2) model fits to the spectra of each of the three SN images. During the unblinding event, a value for H0 was inferred by rescaling the lens-model predicted time delays to match the measured time delays. This is only the second measurement of H0 by the method of a multiply-imaged supernova, and the first by a standard candle. G165 has one of the highest rates of star formation summed up over the background lensed sources, making continued monitoring potentially rewarding for the discovery of additional SNe.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: David Miller (University of Chicago) - Title: Black Boxes or Interpretable Models? Applications of Machine Learning, Symmetries, and Domain Knowledge to High-Dimensional Problems in Particle Physics.
2024-06-18 16:00 - 17:00
Research Progress Meeting
Date: June 18, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: David Miller (University of Chicago)
Title: Black Boxes or Interpretable Models? Applications of Machine Learning, Symmetries, and Domain Knowledge to High-Dimensional Problems in Particle Physics.
Abstract: The world of artificial intelligence (AI) and machine learning (ML) has undergone what some scientists refer to as the “3rd Age of AI” due to the confluence of developments in Algorithms, Computing Resources, and Big Data. Particle Physics has benefitted from, and in many ways strengthened and advanced, progress in AI/ML for decades due to its proliferation of enormous data sets, complex instrumentation, and enormous computing infrastructure. However, there exist both known and unknown deficiencies in our ability to explain “why” some AI/ML models yield a certain result. In this talk, I will discuss some of the context and applications of AI/ML in experimental particle physics. I will then focus on a few projects ongoing in my group that we believe target important problems relevant to the use of machine learning, symmetries, and domain knowledge in particle physics.

Join Zoom Meeting
https://lbnl.zoom.us/j/95679892182?pwd=[REDACTED]
Meeting ID: 956 7989 2182
Passcode: [REDACTED]

Speaker: Max Swiatlowski (TRIUMF) - Title: The LHC’s Next Frontier: Searching for Pairs of Higgs Bosons to Understand the Standard Model and Beyond
2024-07-11 16:00 - 17:00
Research Progress Meeting
Date: July 11, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Max Swiatlowski (TRIUMF)
Title: The LHC’s Next Frontier: Searching for Pairs of Higgs Bosons to Understand the Standard Model and Beyond

Abstract: The discovery of the Higgs boson at the Large Hadron Collider completed the Standard Model, but many fundamental open questions in particle physics remain. One question is particularly simple: how could the Big Bang produce the matter-dominated universe we observe without anti-matter, which should have been produced in equal parts? As the LHC produces collisions faster than ever before, the huge datasets the ATLAS experiment is collecting can provide answers to this question, and others, by enabling the measurement of the extremely rare production of pairs of Higgs bosons. Though difficult to observe, these signatures can directly measure the shape of the Higgs potential: deviations from the Standard Model’s expectations could allow us to understand not just the history of the early universe that created the matter/anti-matter asymmetry, but questions like the future stability of the universe. This talk will focus on the challenges to detecting Higgs boson pairs, and how to interpret them to understand the true shape of the Higgs potential and consequences for physics beyond the Standard Model. The latest results from the ATLAS experiment will be presented, and prospects for future measurements at the High-Luminosity LHC and next-generation colliders will be discussed.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Elliot Reynolds (LBNL) - Title: Probing the associated production of the Higgs boson and charm quarks at ATLAS
2024-08-29 16:00 - 17:00
Research Progress Meeting
Date: August 29, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Elliot Reynolds (LBNL)
Title: Probing the associated production of the Higgs boson and charm quarks at ATLAS

Abstract: One of the most extraordinary discoveries about the universe is that the more of it we explain, the simpler the explanations become. The Standard Model (SM) of particle physics is the culmination of this journey, and explains most of our day-to-day world with just a handful of particles. We know, however, that the SM is incomplete, and because aspects of it still seem arbitrary, we suspect a deeper theory may lie beneath. One of the clearest examples of this is the masses of the fermions, which span many orders of magnitude, seem to have largely arbitrary values, and fall into a clear hierarchy, yet none of these facts are explained in the SM. To understand these things, we should explore how the masses of the fermions arise, which is thought to be due to their interactions with the Higgs boson. Measuring these interactions is therefore a major priority at the Large Hadron Collider, where they have already been measured for the third-generation fermions, and almost for the muon. These measurements remain elusive for the first- and second-generation quarks, though the charm quark is likely our best opportunity to remedy this. Measuring the interactions between the Higgs boson and the charm quark is proving highly challenging, however, and new methods will be needed. This talk presents the first inclusive search for the associated production of the Higgs boson and charm quarks, which uses the ATLAS detector. The search represents an unconventional avenue to probe their interaction strength, and introduces a new Higgs boson production measurement. This work also represents the first usage of Gaussian process regression for direct background estimation in a particle physics data analysis.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Simone Pagan Griso (LBNL) - Title: How a 10 TeV muon collider could be in the particle-physics future
2024-10-03 16:00 - 17:00
Research Progress Meeting
Date: October 3, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Simone Pagan Griso (LBNL)
Title: How a 10 TeV muon collider could be in the particle-physics future

Abstract: A Muon Collider offers the potential for a scalable path towards the next generation of high-energy frontier particle colliders. A 10 TeV center-of-mass collider would allow us to study the Standard Model of particle physics in regimes qualitatively different from what we have been able to explore so far.
At the same time, the short life-time of the muon poses non-trivial technical challenges on both the accelerator and detector design. The last P5 report recognized the high-gain possible from such a machine and refers to that as “the muon shot”.
While studies towards a muon collider have been done for decades, at various degrees of emphasis, the feasibility studies towards a 10 TeV machine have ramped up and caught more and more attention in the last few years, fueled also by the current technology possibilities and the state of the field.
The compact design also offers the possibility of hosting such a collider on the Fermilab site, which has contributed to increase more and more domestic interest as well.
A recent workshop held at Fermilab also started the discussion of forming a US-based Muon Collider organization,in cooperation with the international Muon Collider Collaboration.
In this seminar I will take the occasion of this recent workshop to give to the local crowd a quick overview of the physics case and the state of the design for the accelerator complex and detectors for such a collider, focusing on the technical opportunities and challenges ahead to make this dream-project a reality.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Ibles Olcina Samblas (LBNL) - Title: New constraints on WIMP dark matter from the LUX-ZEPLIN (LZ) experiment
2024-10-10 16:00 - 17:00
Research Progress Meeting
Date: October 10, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Ibles Olcina Samblas (LBNL)
Title: New constraints on WIMP dark matter from the LUX-ZEPLIN (LZ) experiment
Abstract: Dark matter detection experiments based on liquid xenon time projection chambers (TPC) have been steadily increasing in sensitivity to the weakly interacting massive particle (WIMP) over the past two decades. The LUX-ZEPLIN (LZ) experiment, employing a two-phase xenon TPC containing 7 tonnes of liquid xenon, leads the way. Recently, the collaboration released new results from a combined analysis using data from the 2022 and 2024 science campaigns, amounting to an exposure of 4.2 tonne-years. No evidence for an excess over expected backgrounds was found across all the test WIMP masses. The resulting limit on the spin-independent WIMP-nucleon cross section is world-leading for masses above 9 GeV/c2, surpassing previous best limits by about a factor of four. In this talk, I will describe the new LZ results—including a new technique to actively tag background electronic recoils from Pb-214 beta decays, the observation of charge-suppressed two-neutrino double electron capture events from Xe-124 decays, and the bias mitigation technique called “salting”—and briefly discuss what is on the horizon for the liquid xenon TPC community.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Julien Carron (UNIGE) - Title: Delensing the Cosmic Microwave Background
2024-10-22 16:00 - 17:00
Research Progress Meeting
Date: October 22, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Julien Carron (UNIGE)
Title: Delensing the Cosmic Microwave Background
Abstract: Gravitational lensing of the Cosmic Microwave Background is a very valuable cosmological signal, detected at very high significance by several experiments. At the same time, it has also become an hindrance to some important science goals of CMB experiments, most notably for best constraints on a primordial background of gravitational waves. After reviewing current lensing estimation techniques and recent results, I’ll discuss how removal of the lensing signal (`delensing’) typically helps measuring small parameters that affects the CMB polarization. Very sensitive experiments must rely on novel more powerful algorithms to optimally extract or remove the lensing signal: I will present the approach developed in our group in Geneva, together with its forecast performance for upcoming experiments, notably CMB-S4.
Join Zoom Meeting
https://lbnl.zoom.us/j/95679892182?pwd=[REDACTED]
Meeting ID: 956 7989 2182
Passcode: [REDACTED]

Speaker: Kaja Rotermund (LBNL) - Title: LuSEE-Night – the Dark Ages from the Far Side of the Moon
2024-10-24 16:00 - 17:00
Research Progress Meeting
Date: October 24, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Kaja Rotermund, LBNL
Title: LuSEE-Night – the Dark Ages from the Far Side of the Moon
Abstract: The “Dark Ages” refers to the cosmic era between the last scattering of the cosmic microwave background and “Cosmic Dawn,” the time when the first stars and galaxies formed. Only cold, non-luminous hydrogen gas existed during the Dark Ages, which emits at 21 cm (f = 1420 MHz). Through the expansion of the universe, this signal has been redshifted to low radio frequencies that are inaccessible from earth due to distortions of our ionosphere and significant terrestrial radio-frequency interference. This era is therefore largely unexplored and remains one of the least constrained frontiers of modern cosmology. LuSEE-Night is a project that aims to make sensitive measurements across two decades in frequency space from the radio-quiet far side of the moon. In doing so, LuSEE-Night will determine the feasibility of conducting radio-frequency astronomy from the lunar surface and acts as a pathfinder for larger missions in the future.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Vinicius Mikuni (LBNL) - Title: OmniLearn: A Method to Simultaneously Facilitate All Jet Physics Tasks
2024-10-31 16:00 - 17:00
Research Progress Meeting
Date: October 31, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Vinicius Mikuni (LBNL)
Title: OmniLearn: A Method to Simultaneously Facilitate All Jet Physics Tasks
Abstract: Machine learning has become an essential tool in the study of jets, collimated sprays of particles emerging from strong force interactions. Due to their complex, high-dimensional nature, jets can be explored holistically by neural networks in ways that are not possible manually. However, innovations in all areas of jet physics are proceeding in parallel. We show that specially constructed machine learning models trained for a specific jet classification task can improve the accuracy, precision, or speed of all other jet physics tasks. This is demonstrated by training on a particular multiclass generation and classification task and then using the learned representation for different generation and classification tasks, for datasets with a different (full) detector simulation, for jets from a different collision system (pp versus ep), for generative models, for likelihood ratio estimation, and for anomaly detection. Our OmniLearn approach is thus a foundation model and is made publicly available for use in any area where state-of-the-art precision is required for analyses involving jets and their substructure.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Elisabetta Manca (UCLA) - Title: High-precision measurement of the W boson mass at CMS
2024-11-05 16:00 - 17:00
Research Progress Meeting
Date: November 5, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Elisabetta Manca (UCLA)
Title: High-precision measurement of the W boson mass at CMS
Abstract: The W boson mass is measured using proton-proton collision data at corresponding to an integrated luminosity of 16.8 inverse fb recorded during 2016 by the CMS experiment. The W boson mass is obtained from a fit of the two-dimensional pT-η distribution in a sample of W→μν decays, categorized by charge, yielding one of the most precise measurements of the W mass to date.

Join Zoom Meeting
https://lbnl.zoom.us/j/95679892182?pwd=[REDACTED]
Meeting ID: 956 7989 2182
Passcode: [REDACTED]

Speaker: Taylor Hoyt (LBNL) - Title: Toward a Precision Cosmology Measurement of the Hubble Constant
2024-11-07 16:00 - 17:00
Research Progress Meeting
Date: November 7, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Taylor Hoyt (LBNL)
Title: Toward a Precision Cosmology Measurement of the Hubble Constant
Abstract: The local value of the Hubble constant (H0) derived from a Cepheid calibration of nearby supernovae (SNe) continues to disagree with values derived from a Lambda(or w)CDM interpretation of large scale cosmological datasets from, e.g., Planck or DESI. The Cepheid-SN and high-z values of H0 consistently come in close to 73 and 68 km/s/Mpc, respectively, with a latest claim that the Hubble tension has surpassed 5 sigma significance. At the same time, a calibration of the SNe based on the Tip of the Red Giant Branch (TRGB) distance indicator suggests significantly less of a tension, consistently returning values near 69.5 km/s/Mpc. This persistent local Hubble Tension indicates that classical H0 experiments have not yet reached the level of accuracy required of a “precision cosmology” measurement.
To this end, I will discuss ongoing efforts aimed at evaluating, and ultimately reducing, the amount that underestimated systematic errors could contribute to SN-derived H0 measurements and subsequently bias the evidence for or against the Hubble Tension. These efforts include: new, higher signal-to-noise distance measurements from JWST, investigations into the differing treatment of nearby SNe, and the calibration of a new methodology for SN distance measurement twice as precise and accurate as the canonical approach. These paths together will ensure a more complete understanding of the Hubble Tension, its significance (e.g., H0 tails), and will prove crucial in ushering the accuracy of local H0 measurements into the regime of precision cosmology.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Claire Lamman (Harvard) - Title: Untangling the Cosmic Web: Correlations between small-scale clustering and large-scale structure
2024-11-12 16:00 - 17:00
Research Progress Meeting
Date: November 12, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Claire Lamman (Harvard)
Title: Untangling the Cosmic Web: Correlations between small-scale clustering and large-scale structure
Abstract: Gravitational forces from the largest structures in the Universe leave a detectable imprint on galaxies and their local environment. I will present a new approach to tracing the tidal field using these correlations: the intrinsic alignment of small groups of galaxies, or “multipelts”. Multiplets mostly consist of 2-4 galaxies within 1 Mpc/h of each other, and we measure their orientations relative to the galaxy-traced tidal field. Using spectroscopic redshfits from the DESI Y1 survey, we detect intrinsic alignment out to projected separations of 100 Mpc/h and beyond redshift 1. We find a simillar signal regardless of galaxy luminosity or color, which could make multiplet alignment a useful tool for mapping the direction of the tidal field and any cosmological effects which impact it. Our detection demonstrates that galaxy clustering in the non-linear regime of structure formation preserves an interpretable memory of the large-scale tidal field.

Join Zoom Meeting
https://lbnl.zoom.us/j/95679892182?pwd=[REDACTED]
Meeting ID: 956 7989 2182
Passcode: [REDACTED]

Speaker: Gillian Kopp (Princeton University) - Title: Enabling Novel Long-Lived Particle Searches through 5D Calorimetry in the CMS Experiment
2024-11-21 16:00 - 17:00
Research Progress Meeting
Date: November 21, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Gillian Kopp (Princeton University)
Title: Enabling Novel Long-Lived Particle Searches through 5D Calorimetry in the CMS Experiment
Abstract: The Compact Muon Solenoid (CMS) experiment records proton-proton collisions from the LHC to measure properties of the Standard Model and search for new physics. Recently, long-lived particles have emerged as a compelling direction in which to search for physics beyond the Standard Model. As these searches are typically limited by the event selection, implementing dedicated long-lived particle (LLP) triggers provides an excellent avenue to expand experimental coverage into this challenging parameter space. A novel hardware-level LLP trigger has been developed and implemented in the CMS experiment for Run 3 (2022-2026), exploiting the recent hadron calorimeter (HCAL) upgrade. The hardware- and firmware-based trigger algorithm identifies delayed jets, resulting from the decay of massive LLPs, and displaced jets, resulting from LLPs that decay inside the HCAL. This approach significantly increases sensitivity to LLP signatures with soft hadronic final states, including exotic decays of the Higgs boson. I review the trigger implementation, calibration, and performance, showing results from recent HCAL timing scans that produce artificially delayed jets. The data collected with the new triggers provides a first look at the capabilities to capture softer events and expand the phase space accessible in LLP searches.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Simon Koch (Oxford) - Title: Measurements with ATLAS, Measurements of ATLAS: A search for leptoquarks in a final state with two tau leptons, and material measurements of the ITk Pixel detector
2024-12-03 16:00 - 17:00
Research Progress Meeting
Date: December 3, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Simon Koch (Oxford)
Title: Measurements with ATLAS, Measurements of ATLAS: A search for leptoquarks in a final state with two tau leptons, and material measurements of the ITk Pixel detector
Abstract: The ATLAS detector at the LHC has enjoyed great success so far, spanning both new discoveries and precision measurements, and tests of a vast array of theoretical models. This seminar will begin with an introduction to the ATLAS high-mass Drell-Yan di-tau measurement and in particular the search for leptoquarks in this decay channel, including the analysis design and expected results. The search was originally motivated by hints toward lepton-flavour-universality violating behaviour at LHCb, and the leptoquark models explored couple the lepton and quark sectors of the standard model via a new vector or scalar boson. This also introduces unique properties and challenges to the analysis, such as the impact of negative interference with the standard model cross-section.
The future should bring an even greater physics reach thanks to the larger datasets that will be made possible by the High-Luminosity LHC and the ATLAS Inner Tracker (ITk) upgrade. The tracking and vertexing performance of the ITk is critical for future analyses, and hence factors influencing detector performance must be validated so they can be correctly implemented in our Monte-Carlo simulations. One important aspect is the material content of the detector, which has a substantial impact on b-tagging and vertexing resolution due to multiple scattering and hadronic interactions, and is generally only verified using detector data post-commissioning. The second part of this seminar will explore a series of testbeam measurements utilising multiple scattering of low-energy positrons to measure 2D maps of the fractional radiation length x/X₀ of detector components to sub-mm resolution during the R&D phase. A measurement of an ITkPix quad module will be presented, and an outlook will be given on the feasibility of measuring large areas quickly and efficiently with such a technique.
Join Zoom Meeting
https://lbnl.zoom.us/j/95679892182?pwd=[REDACTED]
Meeting ID: 956 7989 2182
Passcode: [REDACTED]

Speaker: Cole Kampa (Northwestern U.) - Title: From Muon CLFV to Collider EFT: Advances in New Physics Searches
2024-12-05 16:00 - 17:00
Research Progress Meeting
Date: December 5, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Cole Kampa (Northwestern U.)
Title: From Muon CLFV to Collider EFT: Advances in New Physics Searches
Abstract: Mu2e, the muon-to-electron conversion experiment at Fermilab, will search for Charged Lepton Flavor Violation (CLFV) – an accidental symmetry forbidden in the Standard Model (SM) of particle physics. Observing CLFV would provide unambiguous evidence of New Physics (NP) beyond the SM. I will briefly outline the experimental design and methodology of Mu2e, emphasizing ongoing efforts to ensure robust physics results. Notably, the introduction of an unbinned maximum likelihood fit has improved the expected sensitivity to Rμe, the muon-to-electron conversion rate, by up to 20%. On the apparatus side, a key component of the experiment is the tracking detector, which reconstructs electron trajectories in a uniform magnetic field. Studies of numerical calculations of the field suggest the calculations should predict the field with 1e-3 level accuracy. However, a 1e-4 level accuracy is required to distinguish signal electrons from the dominant muon decay-in-orbit (DIO) background. To meet this challenge, a custom field mapping apparatus is being developed. The measured field data will be modeled using a novel approach that combines least-squares fitting with a scalar physics-informed neural network (PINN), achieving a modeling fidelity significantly better than the 1e-4 accuracy requirement. I will conclude the CLFV discussion with an overview of two next-generation experiments: Mu2e-II and the Advanced Muon Facility (AMF).

The energy frontier offers a complementary path to NP discovery. Although direct searches at the Large Hadron Collider (LHC) have yet to yield definitive signs of NP, many efforts now focus on model agnostic approaches such as Effective Field Theory (EFT). Recently, the Compact Muon Solenoid (CMS) collaboration observed SM triboson (VVV) production. Building on this milestone, an ongoing CMS analysis employs an EFT framework to constrain heavy NP given the observed rate of VVV. I will conclude by discussing the statistical combination of the various final states being explored in this analysis.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Tyler Horoho (U. of Virginia) - Title: Searching for sub-GeV Dark Matter with the NOvA Near Detector and Measuring the Performance of the Mu2e Cosmic Ray Veto
2024-12-10 16:00 - 17:00
Research Progress Meeting
Date: December 10, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Tyler Horoho (U. of Virginia)
Title: Searching for sub-GeV Dark Matter with the NOvA Near Detector and Measuring the Performance of the Mu2e Cosmic Ray Veto
Abstract: The constituents of dark matter are still unknown, and the viable possibilities span a very large mass range. Specific scenarios for the origin of dark matter sharpen the focus to within about an MeV to 100 TeV. Most of the stable constituents of known matter have masses in this lower range, and a thermal origin for dark matter works in a simple and predictive manner. If there is a non-gravitational interaction between dark matter and ordinary matter, as there must be in the case of a thermal origin, then there is necessarily a production mechanism in accelerator-based experiments. NOvA is a high luminosity long-baseline neutrino oscillation experiment at Fermilab that is capable of searching for signatures of dark matter re-scattering with electrons in its near detector after production in the NuMI target. In this talk, I present an analysis to search for an excess of single electron events in the NOvA near detector consistent with the presence of dark matter-electron scattering and show the expected sensitivity of NOvA to sub-GeV dark matter. I will also discuss a future search for sub-GeV dark matter with the Light Dark Matter eXperiment (LDMX), a planned electron-beam fixed-target missing-momentum search for dark matter at SLAC.
The Mu2e experiment at Fermilab will search for charged-lepton flavor violation through the neutrino-less conversion of a muon to an electron in the presence of a nucleus, a sensitive probe for new physics. Mu2e aims to have single-event sensitivity four orders of magnitude beyond current experimental limits. This sensitivity will require less than one expected background event, which will only be possible with sufficient background vetoing. The largest source of background comes from cosmic-rays, which can produce electrons indistinguishable from a conversion electron signature. To mitigate this, Mu2e will use a cosmic ray veto (CRV), which must exceed a veto efficiency of 99.99% to meet Mu2e’s sensitivity goals. I will present performance studies on the CRV detector components.
Join Zoom Meeting
https://lbnl.zoom.us/j/95679892182?pwd=[REDACTED]
Meeting ID: 956 7989 2182
Passcode: [REDACTED]

Speaker: Shion Kubota (Harvard) - Title: Studying neutrinos in high definition with LAr
2024-12-12 16:00 - 17:00
Research Progress Meeting
Date: December 12, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Shion Kubota (Harvard)
Title: Studying neutrinos in high definition with LAr
Abstract: This talk explores recent advancements in neutrino physics, with a focus on innovative detector technologies developed for the Deep Underground Neutrino Experiment (DUNE). It delves into the use of Liquid Argon Time Projection Chambers (LArTPCs), discussing the challenges associated with the Anode Plane Assembly’s (APA) quality control and how the Digital Wire Analyzer (DWA) has improved the efficiency of wire tension testing. Additionally, the presentation introduces the Q-Pix readout architecture, a promising approach to pixelated detection that streamlines data handling and enhances studies of supernova neutrinos. Simulation results highlight Q-Pix’s potential to improve event reconstruction, extend detection capabilities, and reduce data demands, offering exciting possibilities for future kiloton-scale neutrino experiments.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Sparshita Dey (Oxford) - Title: Chasing Shadows: Illuminating the Path from LZ to the Next Generation Dual-Phase Xe TPC Observatory for Dark Matter
2024-12-17 16:00 - 17:00
Research Progress Meeting
Date: December 17, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Sparshita Dey (Oxford)
Title: Chasing Shadows: Illuminating the Path from LZ to the Next Generation Dual-Phase Xe TPC Observatory for Dark Matter
Abstract: The nature of dark matter remains one of the most significant unsolved challenges in modern physics. Liquid xenon time projection chambers (LXe-TPCs) have emerged as a powerful tool in the search for WIMP dark matter candidates (Weakly Interacting Massive Particles), particularly in the GeV/c2 range. The XENON-LUX-ZEPLIN-DARWIN (XLZD) collaboration embodies the collective knowledge & expertise of generations of LXe-TPC-based experiments, combining three current world-leading experimental and R&D efforts operating at sub-10-tonne Xe target masses. This talk will present the case for XLZD’s next-generation dual phase xenon observatory for dark matter and neutrino physics, with the capability to explore the WIMP parameter space down to the so-called neutrino fog, a background-limited region where neutrino and WIMP signatures look very similar. A discussion of the lessons learned from the operation & analysis chain for the LUX-ZEPLIN experiment will feature, to motivate the design approach for this detector, as well as an overview of novel detector design concepts and exciting current R&D experiments which may both improve sensitivities to low-mass dark matter models and revolutionise the current dark matter direct detection landscape.
Join Zoom Meeting
https://lbnl.zoom.us/j/95679892182?pwd=[REDACTED]
Meeting ID: 956 7989 2182
Passcode: [REDACTED]

Speaker: Ryan Gibbons (UC Berkeley) - Title: Searching for Dark Matter with LZ and Future LZ Upgrades
2024-12-19 16:00 - 17:00
Research Progress Meeting
Date: December 19, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Ryan Gibbons (UC Berkeley)
Title: Searching for Dark Matter with LZ and Future LZ Upgrades
Abstract: Direct detection of particle dark matter remains an outstanding opportunity in understanding the nature of the universe, and for discovery of physics beyond the Standard Model. I will discuss the LUX-ZEPLIN (LZ) experiment’s world-leading WIMP dark matter searches as well as a novel search for neutrinoless double beta decay. In addition, I will present three avenues of instrumentation work at LBNL for potential upgrades to the LZ experiment: a solid xenon TPC (crystaLiZe), light element doping of xenon (HydroX), and mitigation of instrument backgrounds to enable sub-GeV dark matter searches.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Lloyd Knox (UC Davis) - Title: A Polarized Look at the Hubble Constant Problem
2025-01-16 16:00 - 17:00
Research Progress Meeting
Date: January 16, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Lloyd Knox (UC Davis)
Title: A Polarized Look at the Hubble Constant Problem
Abstract: The standard cosmological model has met with enormous empirical success over the past two decades. Continued testing of the model is highly warranted as it relies on additional components beyond the standard model of particle physics: the cold dark matter, the cosmological constant, and some mechanism for generating initial density perturbations. Additional motivation comes from a number of empirical suggestions of deficiencies in the model, with the most statistically significant among these a mismatch between different methods for determining the current rate of the expansion of space (the Hubble constant). In this talk I will present our use of cosmic microwave background (CMB) polarization data from the third generation camera on the South Pole Telescope (SPT-3G) to provide stringent tests of the standard cosmological model and determine the Hubble constant with a standard error of 1.2% using CMB polarization data alone.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Nicole Yunger Halpern (NIST + QuICS + University of Maryland) - Title: Quantum thermodynamics for lattice gauge theories
2025-01-23 16:00 - 17:00
Research Progress Meeting
Date: January 23, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Nicole Yunger Halpern (NIST + QuICS + University of Maryland)
Title: Quantum thermodynamics for lattice gauge theories
Abstract: A key objective in nuclear and high-energy physics is to describe nonequilibrium dynamics of matter, e.g., in the early universe and in particle colliders, starting from the Standard Model. Classical-computing methods, via the framework of lattice gauge theory, have experienced limited success in this mission. Quantum simulation of lattice gauge theories holds promise for overcoming computational limitations. Because of local constraints (Gauss’s laws), lattice gauge theories have an intricate Hilbert-space structure. This structure complicates the definition of thermodynamic properties of systems coupled to reservoirs during equilibrium and nonequilibrium processes. We show how to define thermodynamic quantities such as work and heat using strong-coupling thermodynamics, a framework that has recently burgeoned within the field of quantum thermodynamics. Our definitions suit instantaneous quenches, simple nonequilibrium processes undertaken in quantum simulators. To illustrate our framework, we compute the work and heat exchanged during a quench in a Z2 lattice gauge theory coupled to matter in 1+1 dimensions. The thermodynamic quantities, as functions of the quench parameter, evidence an expected phase transition.
Reference: Davoudi, Jarzynski, Mueller, Oruganti, Powers, and NYH, Phys. Rev. Lett. 133, 250402 (2024). https://journals.aps.org/prl/abstract/10.1103/ PhysRevLett.133.250402
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Krishna Rajagopal (MIT) - Title: Novel Probes of the Primordial Liquid
2025-02-13 16:00 - 17:00
Research Progress Meeting
Date: February 13, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Krishna Rajagopal (MIT)
Title: Novel Probes of the Primordial Liquid
Abstract: Heavy ion collisions reproduce droplets of the trillions-of-degrees-hot liquid that filled the microseconds-old universe, conventionally called quark-gluon plasma (QGP) but better thought of as hot quark soup. Over the past twenty years, data obtained via recreating this primordial fluid have shown that it is the most liquid liquid in the universe, making it the first complex matter to form as well as the source of all protons and neutrons. After a look at what we have learned about the formation and properties of this original liquid from heavy ion collisions, I will focus on the road ahead, in particular on new probes being developed to answer questions like: How does a strongly coupled liquid emerge, given that what you will see if you can probe QGP with high resolution is weakly coupled quarks and gluons? How can we use jets to see the inner workings of QGP and answer this question? And how does the droplet of QGP ripple after it has been probed by a passing jet?
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Aishik Ghosh (UCI), Title: Overcoming challenges of quantum interference in Higgs physics with high-dimensional statistics
2025-02-20 16:00 - 17:00 | 50A-5132 Sessler-Join Zoom
Abstract: Quantum interference between signal and background Feynman diagrams produce non-linear effects that challenge core assumptions going into the statistical analysis methodology in particle physics. I show that for such cases, no single observable can capture all the relevant information needed to perform optimal inference of theory parameters from data collected in our experiments. The optimal data analysis strategy is to perform statistical inference directly on high-dimensional data, without relying on summary histograms. Neural Simulation-Based Inference (NSBI) is a class of techniques that naturally handle high dimensional data, avoiding the need to design low-dimensional summary histograms. We design a general purpose statistical framework in the ATLAS experiment that enables the application of NSBI to full-scale physics analyses, leading to a second publication of the Higgs width measurement on Run2 data, significantly outperforming the previous measurement punished by the experiment on the same data.
Tea and cookies will be served from 3:45 – 4:00 pm in the Sessler conference room.
If you’d like to meet with the speaker, please send your request to Liz Worthy.
Join Zoom Meeting https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]
Meeting ID: 988 5432 2464
Passcode: [REDACTED]

Speaker: Atsushi J. Nishizawa (Gifu Shotoku Gakuen University) - Title: Subaru HSC medium band filter survey and photometric redshift of galaxies
2025-02-25 16:00 - 17:00
Research Progress Meeting
Date: February 25, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Atsushi J. Nishizawa (Gifu Shotoku Gakuen University)
Title: Subaru HSC medium band filter survey and photometric redshift of galaxies
Abstract: Photometric redshift (photo-z) is a well-known technique for measuring the redshift of galaxies using imaging observations. The most challenging aspect of photo-z estimation is that the available information is quite limited, as most imaging surveys utilize broad-band filters, resulting in relatively low wavelength resolution. Traditionally, photo-z is measured by fitting model galaxy spectral energy distributions (SEDs) to the observed fluxes and determining the optimal redshift for each galaxy. An alternative approach is to estimate redshifts using machine learning methods, which can learn complex relationships between observables and redshift.
However, significant improvement in photo-z accuracy is unlikely without incorporating additional information. One possible avenue is to extend the wavelength coverage, while another is to improve the wavelength resolution. We are currently developing medium-band filters to be installed on the Hyper-Suprime Cam at the prime focus of the Subaru Telescope. These medium-band filters will offer moderate spectral resolution and high spatial resolution, providing a substantial amount of additional information. We are preparing to conduct a medium-band filter survey in the coming semesters. In this talk, we will introduce several science cases in collaboration with Euclid, the Roman Space Telescope, DESI-II, and the Subaru Prime Focus Spectrograph (PFS).
Join Zoom Meeting
https://lbnl.zoom.us/j/95679892182?pwd=[REDACTED]
Meeting ID: 956 7989 2182
Passcode: [REDACTED]

Speaker: Ryan Bouabid (Duke) - Title: COHERENT: Using Small Recoils to Look for Big Discoveries
2025-02-27 16:00 - 17:00
Research Progress Meeting
Date: February 27, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Ryan Bouabid (Duke)
Title: COHERENT: Using Small Recoils to Look for Big Discoveries
Abstract: The COHERENT collaboration is pioneering the study of Coherent Elastic Neutrino-Nucleus Scattering (CEvNS), a process only recently observed. Using the Spallation Neutron Source at Oak Ridge National Laboratory, COHERENT has deployed a suite of detectors using diverse technologies and targets. This talk will provide an overview of the collaboration’s experimental efforts and status. Beyond the initial measurements of CEvNS, COHERENT’s results have opened new avenues of discovery potential.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Isobel Ojalvo (Princeton) - Title: Real-time Anomaly Detection at the CMS Experiment
2025-03-13 16:00 - 17:00
Research Progress Meeting
Date: March 13, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Isobel Ojalvo (Princeton)
Title: Real-time Anomaly Detection at the CMS Experiment
Abstract: During Run-3 at the LHC, the search for new physics has significantly expanded. Development of advanced algorithms for the Level-1 trigger, encompassing techniques such as Long-Lived Particles, Data Scouting, and Muon showers to ensure broad data selection at the CMS experiment. Here, we introduce CICADA (Calorimeter Image Convolutional Anomaly Detection Algorithm), a state-of-the-art, fully autonomous AI algorithm engineered to process LHC event data in real-time and trigger on anomalous topologies. Operating directly on the rawest recorded data – the calorimeter energy deposits – CICADA demonstrates sensitivity to Standard Model processes. It unveils potential for Beyond the Standard Model Physics, including the exploration of previously untapped phase space at the LHC. We will also delve into future prospects for triggering at the CMS experiment during the HL-LHC era.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Andrei Cuceu (LBNL) - Title: DESI DR2 results: Measurements of Baryon Acoustic Oscillations and Cosmological Constraints
2025-03-19 15:00 - 16:00
Research Progress Meeting
Date: March 19, 2025
Time: 3:00- 4:00 pm
Location: B50 Auditorium [In-Person and HYBRID]
Speaker: Andrei Cuceu (LBNL)
Title: DESI DR2 results: Measurements of Baryon Acoustic Oscillations and Cosmological Constraints
Abstract: The Dark Energy Spectroscopic Instrument (DESI) is conducting a 5-year redshift survey of 40 million extra-galactic sources over 14,000 square degrees of the northern sky. One of its primary goals is to measure the cosmic expansion history across a wide range of redshifts using baryon acoustic oscillations (BAO). The first DESI results, released in 2024, were based on the first year of data and showed intriguing hints that dark energy may not be described by a cosmological constant. On March 19th we will announce a new set of BAO measurements which are based on the first three years of DESI data. We will also present the cosmological implications of these measurements alone and in combination with cosmic microwave background, supernovae, and weak lensing experiments. These include constraints on the expansion rate of the Universe, the nature of dark energy, and the sum of the neutrino masses.
Join Zoom Meeting
https://lbnl.zoom.us/j/91957913705?pwd=[REDACTED]
Meeting ID: 919 5791 3705
Passcode: [REDACTED]

Speaker: Dean Robinson (LBNL) - Title: New Theory Tools for the Next Generation of Precision Flavor
2025-03-20 16:00 - 17:00
Research Progress Meeting
Date: March 20, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Dean Robinson (LBNL)
Title: New Theory Tools for the Next Generation of Precision Flavor
Abstract: The interpretation of upcoming precision flavor data will require a suite of higher-order calculations and theory descriptions for heavy flavor hadronic processes. We’ll discuss new developments and insights in heavy quark effective theory, that show promise to enable the next generation of precision semileptonic measurements and the interpretation and/or resolution of longstanding anomalies. We’ll also discuss status and plans for the Hammer software library, that is now used across the semileptonic experimental program.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Daniela Köck (University of Oregon) - Title: Exploring Electroweak Paths Beyond the Standard Model with ATLAS
2025-03-27 16:00 - 17:00
Research Progress Meeting
Date: March 27, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Daniela Köck (University of Oregon)
Title: Exploring Electroweak Paths Beyond the Standard Model with ATLAS
Abstract: Phenomenological observations such as dark matter in the universe have long hinted at physics beyond the Standard Model of Particle Physics. The Large-Hadron-Collider (LHC) at CERN has unprecedented capabilities to narrow down on models beyond the Standard Model. Hunting for supersymmetric particles has been a part of the search program since the start of the LHC. Even with these extensive explorations, some well-motivated unexplored parameter spaces only now start to become accessible.
This presentation will give an overview of the current status of searches for supersymmetry produced in electroweak interactions with the ATLAS detector. It will give an overview of the search programme carried out throughout Run-2 of the LHC, discuss a few recent highlights and motivate the necessity of future searches for electroweak supersymmetry.
Join Zoom Meeting
https://lbnl.zoom.us/j/98854322464?pwd=[REDACTED]

Meeting ID: 988 5432 2464

Passcode: [REDACTED]

Speaker: Harry Teplitz (Caltech/IPAC) - Title: Euclid: an ESA Mission with NASA Involvement to Study the Dark Universe
2025-04-08 16:00 - 17:00
Research Progress Meeting
Date: April 8, 2025
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Harry Teplitz (Caltech/IPAC)
Title: Euclid: an ESA Mission with NASA Involvement to Study the Dark Universe
Abstract: Euclid is a European Space Agency mission with NASA involvement to study the geometry and nature of the dark universe. It is optimized for two of the primary probes of dark energy: weak gravitational lensing and galaxy clustering. Euclid launched on 1 July 2023 on a SpaceX Falcon 9 from Cape Canaveral. During its 6 year primary mission, Euclid will survey over 13,000 sq.deg. of extragalactic sky and obtain optical images (530-920nm band), near-infrared images (Y,J,H) and slitless near-infrared grism spectra (1206nm-1892nm, R~480). All Euclid data will be made public to the world community after a proprietary period. Euclid’s first large data set of over 60 square degrees was released on March 19, 2025 (Quick Release 1 or Q1), and the first year of data (about 2000 square degrees) will be released in 2026. I will give an overview of Euclid’s science goals, observing status, and the Q1 data and results.

Join Zoom Meeting
https://lbnl.zoom.us/j/95679892182?pwd=[REDACTED]
Meeting ID: 956 7989 2182
Passcode: [REDACTED]
