LBNL Physics Division Research Progress Meetings

Speaker: Emily Perry (UCL) - Title: Towards the discovery of galactic dark matter: the LZ experiment and beyond
2023-12-19 16:00 - 17:00 UTC
Research Progress Meeting
Date: December 19, 2023
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Emily Perry (UCL)
Title: Towards the discovery of galactic dark matter: the LZ experiment and beyond

Abstract:
The discovery of the nature of dark matter is internationally recognised as one of the highest priorities in science. Its discovery would bring forward a new era in physics and astronomy, simultaneously solving the near 100 year old missing mass problem and delivering the first evidence of physics Beyond the Standard Model (BSM). Dual phase xenon (Xe) time projection chambers (TPCs) have been dominating the search for dark matter for the past 10 years. Now not only targeting WIMPs of mass > 3 GeV/c2, but due to their scalability and advanced technologies, boast world leading sensitivity to other BSM-physics and rare or exotic neutrino physics.
The LUX ZEPLIN (LZ) dark experiment operates at the Sanford Underground Research Facility in South Dakota and is the most sensitive and largest of all Xe TPCs ever constructed. In its first science run of only 60-livedays the experiment has set the world-leading constraints on the existence of WIMPs down to a mass of 9 GeV/c2. This seminar will highlight some of the key work that has led to this result with focus on some of my specific contributions. Giving an exciting glimpse of what the future holds for LZ, I will present the innovative work that is being done on the ramp up to the next science results. I will also discuss both the short and long term future of LZ and the path to an historic dark matter discovery.

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Speaker: Joseph Bramante (Queen's University) - Title: Back to the Future With High Mass Dark Matter
2024-01-18 16:00 - 17:00
Research Progress Meeting
Date: January 18, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Joseph Bramante (Queen’s University)
Title: Back to the Future With High Mass Dark Matter
Abstract: A number of theories predict that dark matter is a supermassive particle or composite state. Discovering dark matter in this high mass regime requires different approaches. I will survey recent developments, including composite dark matter that produces unique signatures in underground experiments, dark matter detectable through its fusion of nuclei in Antarctic ice, and halo substructures heating neutron stars. I will also survey certain experiments from the 80s and 90s, which still provide the best sensitivity to many varieties of high mass dark matter.
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Meeting ID: 988 5432 2464

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Speaker: Philip Harris (MIT) - Title: You can observe a lot by just watching (new AI strategies for the LHC and beyond)
2024-01-25 08:00 - 17:00
Research Progress Meeting
Date: January 25, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Philip Harris (MIT)
Title: You can observe a lot by just watching (new AI strategies for the LHC and beyond)
Abstract: With large amounts of data, a Higgs boson discovery, and world-leading constraints on an enormous amount of parameters and interactions, the Large Hadron Collider has been a phenomenal tool. However, it has reached the middle of life and is going through a mid-life crisis. We venture in a new direction to show how AI approaches are allowing us to do new, unprecedented physics measurements, leading to a mysterious deviation in Higgs boson production at high momentum. Moreover, we show a new result built on contrastive learning and semi-supervised learning strategies where, through physics-motivated choices, we teach an AI to visualize many physics processes simultaneously, allowing it to solve a variety of downstream tasks in one algorithm. The implications are far-reaching, including a world-leading Higgs boson identification and new sensitive approaches in AI-based anomaly detection. Finally, we show a dedicated path for the broad adoption of AI into all aspects of data processing at the Large Hadron Collider and other experiments, including LIGO, that are leading to faster, better, unprecedented results; the kind of results we believe can revitalize an aging accelerator.
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Speaker: Mariel Pettee (LBNL) - Title: Towards a Foundation Model for Fundamental Physics
2024-02-01 16:00 - 17:00
Research Progress Meeting
Date: February 1, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Mariel Pettee (LBNL)
Title: Towards a Foundation Model for Fundamental Physics
Abstract: The launch of ChatGPT in November 2022 ignited an ongoing worldwide conversation about the possible impacts of Large Language Models (LLMs) on the way we work. There is little doubt that LLMs will significantly influence many people’s jobs: one prominent study estimated that about 20% of the US workforce could soon see about 50% of their daily tasks influenced by these models. As scientists, however, the changes in our workflows since the advent of this technology have been relatively minor.
Will this still be the case in 10 years? Could an analogous paradigm shift arise from a foundation model trained on a large amount of scientific data, transforming the way we conduct our research? If so, what can we learn from the development of other foundation models, including LLMs, in their evolution from specialists to (quasi-)generalists? In this talk, I will present some recent work representing very early potential steps towards a foundation model of fundamental physics as well as perspectives on how we should strive to shape such a model to reflect our highest priorities as scientists.
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Speaker: Lindley Winslow (MIT) - Title: The Search for GUT-Scale Axions: Really Big Magnets and Quantum Sensing
2024-02-06 16:00 - 17:00
Research Progress Meeting
Date: February 6, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Lindley Winslow (MIT)
Title: The Search for GUT-Scale Axions: Really Big Magnets and Quantum Sensing

Abstract:
The particle nature of dark matter remains one of the great open questions in physics. There is a broad category of candidates whose mass is so light that they behave more as waves than as particles. The most well-known is the axion, which has had a renaissance as a dark matter candidate as theoretical studies have improved our understanding of axion cosmology and advances in quantum sensing and cryogenics have opened new opportunities for detection. In this talk, I will focus on the search for GUT-Scale axions, the DMRadio Program and the results from the ABRACADABRA demonstrators. If time permits, I will also discuss our other R&D efforts that span from searching for primordial black holes to coupling quantum dots to SNSPDs.

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Speaker: William Coulton (Cambridge) - Title: Novel cosmological tests with precision CMB measurements
2024-02-15 16:00 - 17:00
Research Progress Meeting
Date: February 15, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: William Coulton (Cambridge)
Title: Novel cosmological tests with precision CMB measurements
Abstract: High resolution cosmic microwave background (CMB) experiments provide views of the Universe both at redshift ~1100, when the primary CMB was produced, as well as an integrated view of the Universe between then and now, through CMB secondary anisotropies. In this talk, I will show that CMB secondary anisotropies contain a wealth of cosmological information and are becoming leading cosmological probes. I will present recent measurements from the Atacama Cosmology Telescope collaboration that have mapped out several of these effects. I will then highlight some challenges for these measurements with upcoming CMB experiments, and some unique opportunities, such as tests of the fundamental properties of our Universe.
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Speaker: Clara Verges (Harvard) - Title: A new era for cosmology with current and next-generation CMB experiments
2024-02-20 16:00 - 17:00
Research Progress Meeting
Date: February 20, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Clara Verges (Harvard)
Title: A new era for cosmology with current and next-generation CMB experiments
Abstract:
Cosmology has experienced a considerable surge in the past thirty years, and is now well established as a precision science. While the standard cosmological model provides an effective description of the observed Universe, many fundamental questions remain unresolved. From shedding light on the very first fractions of seconds after the Big Bang to looking for exotic physics, the Cosmic Microwave Background continues to be a unique probe for fundamental physics. The next generation of CMB polarisation observatories, embodied by CMB-Stage 4 for ground observations, will explore this window into the Universe in an unprecedented way, enabling breakthrough science. I will review how current experiments such as the BICEP/Keck telescopes pave the way for this next stage, by developing efficient technologies and observing strategies, and by sharpening constraints on theoretical models. I will then discuss the scientific and technological challenges that the CMB community must meet to ensure the success of future experiments.

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Speaker: Zhen Liu (University of Minnesota) - Title: The Next Leap: Physics Landscape of Future Colliders
2024-02-22 16:00 - 17:00
Research Progress Meeting
Date: February 22, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Zhen Liu (University of Minnesota)
Title: The Next Leap: Physics Landscape of Future Colliders
Abstract: The future direction of High Energy Physics (HEP) is a critical topic, especially considering the large scale and extensive preparation required for upcoming projects. We are at a point filled with opportunities for HEP, featuring a variety of promising paths that highlight its potential for major discoveries. As the introductory talk in our series on future colliders, this presentation aims to examine the potential of these future projects in a clear and comparative manner. I will overview the current landscape and the expected progress in high-energy physics experiments, spotlighting recent initiatives that have resulted in significant achievements in particle physics. The goal of this talk is to outline the broad possibilities that lie ahead for HEP, stressing the importance of innovative approaches necessary to advance this exciting area of science.
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Speaker: Brendan Crill (Jet Propulsion Laboratory) - Title: Sensitivity limits to cosmological constraints on early Universe physics: lessons from Planck for future measurements
2024-02-27 16:00 - 17:00
Research Progress Meeting
Date: February 27, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Brendan Crill (Jet Propulsion Laboratory)
Title: Sensitivity limits to cosmological constraints on early Universe physics: lessons from Planck for future measurements
Abstract:
The past several decades have seen enormous breakthroughs in the understanding of fundamental physics of the Universe through observations of the cosmic microwave background (CMB) and large scale structure. A synergy of rapid advances in technology, data analysis capabilities, and theory has led to an abundance of measurements, which in turn has seen the success of the Lambda-CDM model seeded by early-Universe inflation. This theory explains observations very few free parameters has emerged at explaining the observed structure of the universe.
Further refinements to this model and further characterization of observables in the CMB are a high priority for a deeper understanding of the nature of the physics of inflation and the evolution of structure across cosmic time. This will come about through measurements of non-Gaussianity, lensing, and the imprint of tensor modes in large-scale CMB polarization among other observables.
To achieve these refinements, projects have focused on improvements in raw sensitivity via new and more powerful detectors arrays with vastly more elements.
However, the success of earlier measurements has only come about through understanding and correction of systematic errors, understanding astrophysical foregrounds: more powerful instruments with better sensitivity are likely to uncover new challenges.
Here I describe lessons learned from the Planck mission at handling unforeseen instrumental and observational challenges and discuss prospects for fulfilling the sensitivity promise offered by large-scale structure projects such as SPHEREx and future CMB measurements.

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Speaker: Petra Merkel (Fermilab) - Title: Detectors for Future Colliders
2024-02-29 16:00 - 17:00
Research Progress Meeting
Date: February 29, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Petra Merkel (Fermilab)
Title: Detectors for Future Colliders
Abstract: I will present detector capabilities that need to be developed in order to address physics requirements at future collider experiments. In addition to laying out common detector technologies that will be useful at various collider experiments, I will also summarize differences and special requirements at the different collider options. Furthermore, I will give a brief overview of the state of the art of the R&D in some of the most crucial areas where technology development is needed in detector instrumentation.
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Speaker: Roy Aleksan (CEA-Saclay) - Title: Status of the Future Circular Collider (FCC)
2024-03-05 16:00 - 17:00
Research Progress Meeting
Date: March 5, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Roy Aleksan (CEA-Saclay)
Title: Status of the Future Circular Collider (FCC)
Abstract:
While the LHC is continuing its outstanding program, one needs to decide what the next large accelerator project in particle physics will be. There is a general global consensus that an e+e- collider is the next priority. In accordance with the 2020 European Strategy Update, the technical and financial feasibility of a circular high energy hadron collider at CERN with a centre-of-mass energy of at least 100 TeV and with an electron-positron Higgs and electroweak factory as a possible first stage has been launched in Europe. In the present talk, we shall discuss the status of this endeavor including the physics motivation, the corresponding technical implications for the detectors as well as the status of the study of the accelerator complex with special emphasis on the e+e- collider.

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Speaker: Cameron Geddes (LBL Accelerator Division) - Title: Accelerators for Future Colliders
2024-03-07 16:00 - 17:00
Research Progress Meeting
Date: March 7, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Cameron Geddes (LBL Accelerator Division)
Title: Accelerators for Future Colliders
Abstract: Particle physics motivates next generations of colliders ranging from a fraction of a TeV for precision Higgs physics to the 10 TeV parton Center of Mass (pCM) scale for both broad new physics and deep characterization of the Higgs sector. Designs for Higgs factory colliders are being formalized with the aim of a project late in the decade. The 10 TeV pCm range will place radical new demands on accelerator capability, efficiency, and cost. At the same time, accelerator science is advancing rapidly with a set of new technologies under development that make it feasible to address this frontier. These technologies, including high field magnets for proton machines, muon colliders incorporating cooling, and high gradient linear wakefield lepton colliders all require development in order to allow us to make a confident, informed decision on the path forward. These colliders, a combination of general and targeted R&D, and interactions with the detector and particle physics community to develop them will be discussed.
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Speaker: Colin Hill (Columbia) - Title: Uncovering Physics Beyond the Standard Model in the Cosmic Microwave Background
2024-03-12 16:00 - 17:00
Research Progress Meeting
Date: March 12, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Colin Hill (Columbia)
Title: Uncovering Physics Beyond the Standard Model in the Cosmic Microwave Background
Abstract:
The cosmic microwave background (CMB) anisotropy remains the cleanest, most powerful probe of fundamental physics in the cosmos. Measurements of the small-scale CMB temperature and polarization fields are set to undergo transformative improvements in the coming decade, culminating in the CMB-S4 experiment, which will open new windows into physics beyond the standard models (BSM) of particle physics and cosmology. I will first discuss my ongoing work in the Atacama Cosmology Telescope collaboration focused on cosmological parameter constraints from high-resolution CMB power spectra, with a particular emphasis on constraining BSM physics operating just prior to recombination, including new relativistic particles and new pseudo-scalar fields. I will describe high-precision end-to-end tests of our entire analysis pipeline on realistic, non-Gaussian sky simulations containing all relevant Galactic and extragalactic foregrounds, tightly coupled to a detailed instrument model. I will then turn to novel searches for BSM physics in CMB secondary anisotropies, as could be imprinted by the screening of CMB photons by massive dark photons or axion-like particles. I will show the first results of searches for these signals in CMB data, enabled by my group’s state-of-the-art needlet internal linear combination code. Finally, I will discuss new analysis methodologies for more optimally cleaning non-Gaussian foregrounds in CMB maps, with applications to both primordial B-mode searches and small-scale secondary anisotropy measurements. I will conclude with a look ahead to the prospects for BSM physics from the Simons Observatory and CMB-S4.

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Speaker: Matthias Hohenberger (LLNL) - Title: Demonstrating fusion ignition in the laboratory for the first time
2024-03-14 16:00 - 17:00
Research Progress Meeting
Date: March 14, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Matthias Hohenberger (LLNL)
Title: Demonstrating fusion ignition in the laboratory for the first time
Abstract: At approximately 1 am on December 5th, 2022, a fusion experiment at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory achieved, for the first time, a target gain exceeding 1. By imploding a small capsule containing deuterium-tritium fuel with 2.05 MJ of laser light, the resulting fusion reactions released a total energy of 3.15 MJ of nuclear fusion yield, thus exceeding the initial input energy. This was the first time for a laboratory experiment to meet the 1997 definition by the National Academy of Sciences of fusion ignition, an accomplishment six decades in the making. It is the result of focused work by a multi-lab team and required significant advances in high-energy-density physics, as well as laser, target, and diagnostics capabilities. This talk will discuss this momentous result, the steps that went into achieving it, and the implications of this achievement for Inertial Fusion Energy.
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Speaker: Christian Reichardt (Melbourne) - Title: Observing the oldest light in the Universe from the South Pole: Gravitational waves, Neutrinos and more!
2024-03-19 16:00 - 17:00
Research Progress Meeting
Date: March 19, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Christian Reichardt (Melbourne)
Title: Observing the oldest light in the Universe from the South Pole: Gravitational waves, Neutrinos and more!
Abstract:
The cosmic microwave background (CMB) radiation is the oldest light we can see. Since it bears the imprint of the universe just after the Big Bang (at a mere 0.003% of the universe’s age today), observations of the CMB are a crucial tool in our quest to understand how the Universe began and what its future holds. The South Pole is one of the best sites on Earth for these observations, and is the home of the South Pole Telescope (as well as CMB-S4 in the future). In this talk, I will present the latest CMB power spectra measurements from the SPT-3G instrument on the South Pole Telescope, and the resulting constraints on cosmology.

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Speaker: Tom Shutt (SLAC) - Title: GammaTPC: A novel next generation Compton telescope
2024-03-21 16:00 - 17:00
Research Progress Meeting
Date: March 21, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Tom Shutt (SLAC)
Title: GammaTPC: A novel next generation Compton telescope
Abstract: I will talk about GammaTPC, a new instrument concept for measuring astrophysical gamma rays in the MeV energy range. This part of the sky is a largely unexplored mostly due to the difficulty of measuring MeV photons, but the potential payoff is large, particularly in the upcoming era of multi-messenger transient astrophysics. GammaTPC attacks this difficulty using liquid argon time projection chamber (TPC) technology, which appears to have important advantages over several other techniques that are being pursued. A core part GammaTPC is GAMPix, a new charge readout scheme that enables fine grained readout over large area at very low power, and has other potential applications including neutrino physics. There are a few other amusing challenges to fielding a liquid noble TPC in low Earth orbit.
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Speaker: Raphael Flauger (UC San Diego) - Title: Deciphering the Beginning
2024-03-26 16:00 - 17:00
Research Progress Meeting
Date: March 26, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Raphael Flauger (UC San Diego)
Title: Deciphering the Beginning
Abstract:
The cosmic microwave background (CMB) contains a wealth of information about cosmology as well as high-energy physics. It tells us about the composition and geometry of the universe, the properties of neutrinos, dark matter, and even the conditions in our universe long before the cosmic microwave background was emitted. After a brief introduction, I will discuss what we may hope to learn about the very early universe from upcoming CMB experiments that search for the imprint of primordial gravitational waves. One of the key challenges of this endeavor is the polarized emission from our galaxy. I will discuss our recent efforts to model and better understand the emission with the help of MHD simulations.

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Speaker: Chiara Salemi (SLAC) - Title: Seeing the invisible: the search for axion dark matter
2024-03-28 16:00 - 17:00
Research Progress Meeting
Date: March 28, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Chiara Salemi (SLAC)
Title: Seeing the invisible: the search for axion dark matter
Abstract: The presence of dark matter provides some of the most persuasive evidence for the existence of physics beyond the Standard Model. One compelling dark matter candidate is the axion, a light boson that was originally postulated as a solution to another outstanding issue, the strong CP problem in QCD. This talk covers two experimental programs to search for axion dark matter with advanced quantum sensors: DMRadio and BREAD. DMRadio searches for low-mass (long-wavelength) axions using a lumped-element detection method, while BREAD searches for relatively high-mass (short-wavelength) axions using a reflector. I will discuss the status and upcoming plans for these two programs, with a focus on the quantum sensors that enable these kinds of searches.
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Speaker: Boryana Hadzhiyska (UC Berkeley) - Title: Solving big-scale problems with small-scale models in the era of CMB-S4
2024-04-02 16:00 - 17:00
Research Progress Meeting
Date: April 2, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Boryana Hadzhiyska (UC Berkeley)
Title: Solving big-scale problems with small-scale models in the era of CMB-S4
Abstract: In this talk, I will focus on some of the new opportunities and new challenges that CMB-S4, the next-generation cosmic microwave background (CMB) experiment, presents, and I will offer a viable path forward to meeting and exceeding the goals we have set up for it. The CMB has played a huge role in shaping our understanding of the history, evolution and contents of our Universe. From our observations of the CMB, we have attained a good grasp of about 13.8 billion years of cosmic history, but our direct and indirect observations are limited to a much smaller range in energy scale, which leaves unresolved some of the biggest puzzles such as the mechanism that seeded the primordial fluctuations and the nature of the dark sector. I will discuss how we can leverage observations of the CMB to learn about these much earlier periods of cosmic history and also, how the CMB provides complementary probes of the lower-redshift universe. On large scales, the B-mode polarization signal can reveal the origin of primordial fluctuations, whereas the small-scale signal holds information about the presence of non-standard light relics and the sum of the neutrino masses. However, measuring the primordial signal is a non-trivial task, as on its way to us, the signal has picked up contributions from lensing and astrophysical sources, known as foregrounds. The best way to design accurate approaches for mitigating these foregrounds is via realistic all-sky simulations. I will present new techniques for painting foregrounds onto large-volume simulations, using physically motivated models that close the loop between simulations and observations. In addition, I will discuss ways of optimizing the CMB lensing reconstruction techniques, which is crucial for improving our constraints on primordial quantities such as the number of light relics and the tensor-to-scalar ratio as well as the sum of neutrino masses. Finally, I will argue that synergies between CMB secondaries and large-scale structure surveys can place tight constraints on cosmology and astrophysics. The measurement precision of CMB-S4 will be unmatched, but in order to make the most out of it, we need a big step-up in our analysis and theory tools, including the development of realistic all-sky simulations as well as techniques for optimal extraction of the small-scale cosmological signal.

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Speaker: Joshua Combes (JILA) - Title: Game of Qubits: winter is coming
2024-04-04 16:00 - 17:00
Research Progress Meeting
Date: April 4, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Joshua Combes (JILA)
Title: Game of Qubits: winter is coming
Abstract: The ‘Quantum Winter’ is a term that paints a scenario where the progress in quantum computing might significantly slow down, accompanied by a decrease in both public and private investment, and mounting skepticism regarding the field’s potential and future accomplishments. This concept echoes the historical ‘AI Winters,’ periods of contraction in artificial intelligence research. In this presentation, I will first evaluate our current milestones in quantum hardware development, setting the stage for an understanding of why there’s a growing concern about an impending Quantum Winter. Following this, I’ll share my forecasts, pinpointing specific years when we might anticipate this cooldown to manifest. To conclude, I’ll turn the lens inward, contemplating proactive strategies and responses we, as a research community, should consider to navigate and possibly mitigate the impact of this predicted quantum chill. This talk aims not only to forecast but to fortify our resolve in advancing quantum computing through potential adversities.
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Speaker: Michel Piat (APC-IN2P3) - Title: The Q&U Bolometric Interferometer for Cosmology (QUBIC): status and perspectives
2024-04-09 16:00 - 17:00
Research Progress Meeting
Date: April 9, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Michel Piat (APC-IN2P3)
Title: The Q&U Bolometric Interferometer for Cosmology (QUBIC): status and perspectives
Abstract: QUBIC (Q & U Bolometric Interferometer for Cosmology) is an international ground-based experiment dedicated in the measurement of the polarized fluctuations of the millimeter sky and especially the Cosmic Microwave Background (CMB). It is based on bolometric interferometry, an original detection technique which combine the immunity to systematic effects of an interferometer with the sensitivity of low temperature incoherent detectors. QUBIC is currently in commissioning in Argentina, at the Alto Chorrillos mountain site at 5000m a.s.l. near San Antonio de los Cobres, in the Salta province. After a description of the QUBIC instrument, I will present the last results of the first characterization phases with a focus on the detectors and readout system based on NbSi Transition Edge Sensors (TESs) cooled to 320mK. The perspective of spectro-imaging will also be described allowing for better foreground mitigation. This feature will soon be tested with QUBIC and could represent a significant breakthrough in CMB polarimetry.

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Speaker: Slavomira Stefkova (Karlsruhe Institute of Technology) - Title: Glimpse of a Rare B Decay with Two Invisible Neutrinos at Belle II
2024-04-11 16:00 - 17:00
Research Progress Meeting
Date: April 11, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Slavomira Stefkova (Karlsruhe Institute of Technology)
Title: Glimpse of a Rare B Decay with Two Invisible Neutrinos at Belle II
Abstract: The decay of B+→K+νν̄ is mediated by flavor-changing neutral current. In the Standard Model, the rate for this elusive process is predicted to be 6×10^-6, while enhancements are foreseen in many New Physics models. Searching for B+→K+νν̄ decays is, however, experimentally challenging as this decay is not only rare but also contains two neutrinos, leaving no signature in the detector. In this talk, I will show you details of the newest measurement of the rate of B+→K+νν̄ decays, which is based on 362 fb^-1 of SuperKEKB electron-positron collision data collected at the Upsilon(4S) resonance by the Belle II experiment in Tsukuba, Japan. Using two different but complementary reconstruction techniques, we found, for the first time, evidence for the B+→K+νν̄ process. At the end of my talk, I will highlight other future opportunities in B-decays with invisible signatures.
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Speaker: Julien Guy (LBNL) - Title: The Dark Energy Spectroscopic Instrument First Year Results: Cosmic Expansion History with Baryon Acoustic Oscillations
2024-04-16 16:00 - 17:00
Research Progress Meeting
Date: April 16, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Julien Guy (LBNL)
Title: The Dark Energy Spectroscopic Instrument First Year Results: Cosmic Expansion History with Baryon Acoustic Oscillations
Abstract: The Dark Energy Spectroscopic Instrument (DESI) collaboration 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 with baryon acoustic oscillations (BAO). I will present the measurement of BAO in galaxy, quasar and Lyman-alpha forest tracers from the first year of observation. With 5.7 million galaxy and quasar redshifts in the range 0.1 < z < 2.1, and 420,000 Lyman-alpha forest quasars at higher redshift, the aggregate precision on BAO is of 0.52% at z<2.1 and 1.1% at an effective redshift z=2.3, surpassing in a year two decades of observations with the SDSS. I will present some of the numerous validation tests performed with simulations and blinded data. I will then highlight the main cosmological results, with improved constraints on the dark energy equation of state, the Hubble parameter, spatial curvature, and the sum of neutrino masses.

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Speaker: Caterina Vernieri (SLAC) - Title: Delving into the Unknown: The Higgs Boson at Future Colliders
2024-04-25 16:00 - 17:00
Research Progress Meeting
Date: April 25, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Caterina Vernieri (SLAC)
Title: Delving into the Unknown: The Higgs Boson at Future Colliders
Abstract: The Higgs boson was discovered in 2012 by the ATLAS and CMS experiments at the world’s most powerful particle collider, the Large Hadron Collider (LHC) in Geneva, Switzerland. This particle plays a unique role in fundamental physics. It gives all of the known elementary particles, including itself, their masses. While we now have a strong evidence that the Higgs field is indeed the unique source of mass for the known elementary particles, the next step is to search for new interactions that could also explain why the Higgs field has the properties required by the Standard Model of particle physics. We have no clear roadmap to this new theory but the Higgs boson plays a crucial role in this quest. The goal of a next-generation e+e- collider is to carry out precision measurements to per-cent level of the Higgs boson properties that are not accessible at the LHC. In this talk we present the challenges and possibilities for the next e+e- collider and recent progress. The exploitation of the complementarity between LHC and future colliders will be the key to understanding fundamentally the Higgs boson.
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Speakers: Career Panel (Industry) - Title: How to start a career in industry: A panel discussion with physicists who work in industry
2024-04-30 16:00 - 17:00
Research Progress Meeting
Date: April 30, 2024
Time: 4:00- 5:00 pm
Location: 50-4-Auditorium [In-Person and HYBRID]
Panelists:

Marat Freytsis (Anthropic)
Riccardo Manenti (Rigetti)
Ronald Goossens (ASML)
Kathy Copic (Fieldwork Partners)
Mark Dishner (Lam Research)
Ana Ovcharova (Ionq)

Title: How to start a career in industry: A panel discussion with physicists who work in industry
Abstract: In this panel discussion postdocs and students will have the opportunity to ask questions about how to approach a career in industry. How do you make the right connections? How to craft a compelling application? What does work-life balance look like in industry? etc etc
Most of the time will be reserved for interactions with the audience, so bring along all your questions about finding positions in industry.

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Speaker: Maria Vincenzi (Duke University) - Title: Cosmological results from the Dark Energy Survey Supernova program
2024-05-09 16:00 - 17:00
Research Progress Meeting
Date: May 9, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Maria Vincenzi (Duke University)
Title:Cosmological results from the Dark Energy Survey Supernova program
Abstract: The Dark Energy Survey Supernova sample is the largest and deepest Type Ia Supernova (SN Ia) sample from a single telescope to date. It includes 1600 photometrically identified SNe Ia with high-quality multi-band light curves and spectroscopic redshifts. With a redshift range spanning between 0.1 to 1.2 and a well-defined selection function, this SN sample constitutes an ideal dataset for cosmology. In my talk, I will present the cosmological results from this unique sample and show that DES SNe, combined with publicly available low-z SN samples, provides excellent constraints on the Dark Energy equation of state from SN Ia.
Looking towards the future, I will discuss how future optical ground-based surveys like Rubin, and space-based near-infrared observatories like the Nancy Grace Roman Space Telescope, will revolutionise SN Ia cosmology and potentially answer some of the most pressing questions of modern cosmology.
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Speaker: Deborah Harris (York/FNAL) - Title: Precision Neutrino Oscillation Measurements: Are we there yet?
2024-05-28 16:00 - 17:00
Research Progress Meeting
Date: May 28, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Deborah Harris (York/FNAL)
Title: Precision Neutrino Oscillation Measurements: Are we there yet?
Abstract: Neutrino Oscillations, one of the precious few signatures of beyond the standard model physics, offer an exciting opportunity to study the universe. Neutrino oscillation measurements can give us new insight into what generate particle masses and what might generate the abundance of matter over antineutrino that we currently enjoy. Making precision oscillation measurements is challenging though, in part due to their miniscule probability to interact with matter. The Deep Underground Neutrino Experiment (DUNE), currently under construction, aims to make precision measurements of neutrino oscillations across a broad range of neutrino energies, with a goal of not only getting precise oscillation parameters in the new standard “3-neutrino-flavour paradigm” but also to test the framework itself. Making precision oscillation measurements also requires a thorough understanding of the way neutrinos interact in nuclei in order to measure the oscillation probability as a function of neutrino energy. This talk will review recent progress on DUNE as well as a few recent neutrino interaction measurements from MINERvA that are helping to lay the foundations of future oscillation measurements.

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Speaker: Emma Tolley (EPFL) - Title: Radio Cosmology: Imaging the Cosmic Dawn
2024-05-30 16:00 - 17:00
Research Progress Meeting
Date: May 30, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Emma Tolley (EPFL)
Title: Radio Cosmology: Imaging the Cosmic Dawn
Abstract: Radio astronomers are engaged in ambitious new projects to detect faster, fainter, and more distant astrophysical phenomena. The flagship project is the Square Kilometer Array Observatory (SKAO). The SKAO will use thousands of individual radio receivers linked through interferometry to create the world’s largest radio telescope with unprecedented sensitivity, field of view, and survey speed, allowing us to map the neutral hydrogen throughout our Universe from nearby galaxies to the Cosmic Dawn epoch when stars and galaxies first formed. However, as a groundbreaking observational facility, SKA introduces new astrophysical, computational, and data analysis challenges. I present an overview of computational challenges and solutions for the SKAO, new techniques for image synthesis, and applications of AI in 21cm cosmology experiments.
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Speaker: Rachel Mannino (LLNL) - Title: Dark Matter Searches with the Axion Dark Matter eXperiment (ADMX)
2024-06-06 16:00 - 17:00
Research Progress Meeting
Date: June 6, 2024
Time: 4:00- 5:00 pm
Location: Sessler Conference Room- 50A-5132 [In-Person and HYBRID]
Speaker: Rachel Mannino (LLNL)
Title: Dark Matter Searches with the Axion Dark Matter eXperiment (ADMX)
Abstract: For decades, we have been collecting indirect astrophysical evidence that ordinary matter only
comprises about 5% of the mass-energy content in the universe with the remaining split between dark
matter and dark energy. Potential dark matter candidates span a wide parameter space, and many
parallel efforts are in progress to detect and identify the nature of dark matter. The Axion Dark Matter
eXperiment (ADMX) searches for the axion, a leading low-mass dark matter candidate and a potential
solution to the strong CP problem, by searching for an axion’s conversion to two microwave photons in a
strong magnetic field. I will present an overview of ADMX’s past and present axion searches using a
single microwave cavity and the planned next generation ADMX-2A and ADMX-EFR (Extended
Frequency Range) detectors.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore
National Laboratory under Contract DE-AC52-07NA27344.
LLNL-ABS-864832
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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
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.
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