INPA

VIRTUAL INPA SEMINAR - Chia-Cheng Chang (LBNL)
2020-05-15 12:00 - 13:00 (America/Los_Angeles)
Speaker: Chia-Cheng Chang (LBNL)
Title: Time evolution of open quantum many-body systems
Abstract:
The increasing interest and efforts put forth towards the development of quantum computing have lead to a shift in how one goes about tackling problems that are typically thought of as difficult. In this talk I will discuss a specific paradigm of quantum computing called adiabatic quantum computing, and narrow the scope to discuss what is known as quantum annealing. In particular, the first part of the talk will be devoted to discussing what quantum annealing is, and its connection with adiabatic quantum computing. I will follow by discussing the scope of problems that quantum annealers can hope to solve, include an example for tackling integer linear programming. I will end by discussing our simulation of an open quantum many-body system and compare against experimental results obtained from a DWave quantum annealer. On the DWave, we employ a modified time evolution schedule and observe an improvement in performance. Results from the simulation provide a possible explanation of the underlying physics by correlating algorithmic improvements to the interplay between quantum decoherence and many-body localization..
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https://lbnl.zoom.us/j/99612217893
Meeting ID: 996 1221 7893

VIRTUAL INPA SEMINAR – Eric Charles (Stanford) - Friday, May 22, 2020
2020-05-22 12:00 - 13:00
Speaker: Eric Charles (Stanford)

Title: Indirect Dark Matter Detection: Status and Summary of WIMP Searches

Abstract:
The nature of dark matter is a longstanding enigma of physics; it may consist of particles beyond the Standard Model that are still elusive to experiments. Searches for signals from the annihilation or decay of weakly interacting massive particle (WMIP) dark matter using observations of the gamma-ray sky have come to prominence over the last decade. Current and upcoming telescopes such as the Fermi Large Area Telescope (Fermi-LAT) and the Cerenkov Telescope Array are particularly well suited for searching for products of the interactions of dark matter particles. In this talk I will describe astrophysical targets studied for evidence of dark matter, and review the status of these searches. I will also discuss the factors that determine the sensitivities of these searches, including the magnitudes of the signals and the relevant backgrounds, considering both statistical and systematic uncertainties. Finally, I will discuss how upcoming observatories operating across the electromagnetic spectrum could change this field.

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https://lbnl.zoom.us/j/91138499248
Meeting ID: 911 3849 9248

VIRTUAL INPA SEMINAR – Luca Pagani (UC Davis)
2020-05-29 12:00 - 13:00
Speaker: Luca Pagani (UC Davis)
Title: Recent results from the ACED and the ARTIE experiments
Abstract:
Liquid argon is becoming a popular medium for particle detection, with applications ranging from low-background dark matter searches to high-energy neutrino detection. Because neutrons represent both an important source of background (e.g., for dark matter experiments) and a product of signal events (e.g., neutrino-induced spallation neutrons), a good understanding of their interactions in argon is a requirement for precision physics measurements. Despite being one of the most basic quantities needed to describe low-energy neutron transport, the neutron cross section on argon is not clearly understood. In particular, the existing activation measurements for the thermal neutron capture cross section show significant disagreements. Moreover, in the energy range 40-70 keV theory predicts an anti-resonance in the $^{40}$Ar cross section near $57$\,keV, but the existing data, coming from an experiment performed in the 90s (Winters. et al.), does not support this. To resolve these disagreements, two experiments were performed using a time of flight neutron beam at Los Alamos National Laboratory. The Argon Capture Experiment at DANCE (ACED) first measured the differential cross section of $^{40}$Ar$(n,gamma)^{41}$Ar using the Detector for Advanced Neutron Capture Experiments (DANCE), a $sim$4$pi$ gamma spectrometer. A fit to the differential cross section from $0.015-0.15$\,eV, assuming a $1/v$ energy dependence, yields $sigma^{2200} = 673 pm 26 text{ (stat.)} pm 59 text{(sys.)}$\,mb. Then, the Argon Resonance Transmission Interaction Experiment (ARTIE) measured the transmission coefficient for neutrons through a thick ($sim 3$\,atoms/b) liquid natural argon target in the energy range 40-70 keV. This measurements are crucial for the Deep Underground Neutrino Experiment (DUNE) since allow a viable means of calibration and a deeper understanding of signals and backgrounds for the low energy science program.
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https://lbnl.zoom.us/j/97119161552
Meeting ID: 971 1916 1552

VIRTUAL INPA SEMINAR – Micah Buuck (SLAC)
2020-06-05 12:00 - 13:00
Speaker: Micah Buuck (SLAC)
Title: Neurtrinoless Double-Beta Decay and Radioactive Backgrounds in the MAJORANA DEMONSTRATOR
Abstract: Neutrinoless double-beta decay (0νββ) is a lepton-number-violating process whose existence would indicate that neutrinos are Majorana fermions. The MAJORANA collaboration is searching for 0νββ in germanium-76 using a modular array of high-purity germanium detectors, housed at the Sanford Underground Research Facility in Lead, South Dakota. This presentation will show the results of an in-depth study of the backgrounds visible to the array, and the details behind a model to explain their sources.
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https://lbnl.zoom.us/j/99678795337
Meeting ID: 996 7879 5337

VIRTUAL INPA SEMINAR – Jorge Morales (SLAC)
2020-06-12 12:00 - 13:00
Speaker: Jorge Morales (SLAC)
Title: TBA
Abstract: TBA

VIRTUAL INPA SEMINAR – Jorge Morales (SLAC)
2020-06-12 12:00 - 13:00
Speaker: Jorge Morales (SLAC)
Title: Simulation of Dark Matter and Standard Model Interactions in the SuperCDMS Soudan Experiment
Abstract:
Astronomical observations lead us to believe that dark matter constitutes the majority of the mass of the Universe, yet it has never been directly observed experimentally. The Super Cryogenic Dark Matter Search Experiment (SuperCDMS) aims to discover the particle nature of dark matter, by developing and using some of the most sensitive detectors ever built. Previous analyses with SuperCDMS set world leading sensitivity limits to dark matter interactions, but the analysis techniques have not been based on simulations. Now we have developed an efficient simulations infrastructure that will help better understand the detectors, develop a better background model, and optimize the next generation dark matter searches. I present the fully-functional simulations infrastructure to produce high quality samples as well as results for the charge system readout simulations, and comparisons to expectations from data. Whilst improvement is still needed, I will show that our simulations well-reproduce dominant features of data, bringing SuperCDMS closer to a robust simulation-based analysis method, much needed for the upcoming SuperCDMS dark matter searches.
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https://lbnl.zoom.us/j/95746341336
Meeting ID: 957 4634 1336

VIRTUAL INPA SEMINAR – Bradley Kavanagh (IFCA - Spain)
2020-06-19 11:00 - 12:00
Speaker: Bradley Kavanagh (IFCA – Spain)
Title: Detection Dark Matter around Black Holes with Gravitational Waves
Abstract: The observation of Gravitational Waves (GWs) has opened up a whole new avenue for constraining and detecting particle Dark Matter (DM). One of the most promising systems to study is the Intermediate Mass Ratio Inspiral (IMRI): a stellar-mass compact object such as a neutron star inspiraling towards an intermediate mass black hole, thousands of times more massive than the Sun. Sub-hertz GWs emitted during the inspiral should be detectable by future space-based observatories such as LISA. But the presence of DM in the system can have subtle dynamical effects on the inspiral, altering the waveform and hopefully allowing us to map out the DM distribution. I will discuss ongoing work to study these systems carefully and self-consistently, in order to determine whether such a signal can be detected and what we can learn about Dark Matter if it is.
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https://lbnl.zoom.us/j/95929756869
Meeting ID: 959 2975 6869

VIRTUAL INPA Seminar - Matthew Szydagis (UALbany)
2020-06-26 12:00 - 13:00
Speaker: Matthew Szydagis (UALbany)
Title: The Road to Discovering Sub-GeV Dark Matter Using Supercooled Liquids
Abstract:The latest developments in the search for low-mass dark matter with the snowball chamber technology, essentially a reverse bubble chamber using supercooled water instead of superheating, will be presented. The latest calibration data sets with neutron and gamma-ray radioactive calibration sources will be discussed, with implications reviewed on the extremely low energy threshold expected (sub-keV) and background discrimination as a function of thermodynamic conditions. The most recent three-dimensional image analysis will be shown with position reconstruction and multiple scattering. Information gathered from all prototypes will be analyzed together to form a projected sensitivity curve for both spin-independent and spin-dependent (proton) coupling.
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https://lbnl.zoom.us/j/99047273608
Meeting ID: 990 4727 3608

SPECIAL VIRTUAL INPA SEMINAR – Benjamin Schmidt (LBNL)
2020-06-29 12:00 - 13:00
Speaker: Benjamin Schmidt (LBNL)
Title: A new limit from the search for 0νββ of 100Mo from the CUPID-Mo experiment

Abstract: The CUPID-Mo experiment, currently taking data at the Laboratoire Souterrain de Modane (France), is a demonstrator for CUPID, the next-generation upgrade of the first ton-scale cryogenic 0νββ-search, CUORE. The experiment is searching for 0νββ decay of 100Mo with an array of 20 enriched ~0.2 kg Li2MoO4 crystals. The detectors are operated deep under the Frejus mountain at a depth of 4800 m.w.e. in a dilution refrigerator at ~20 mK. They are complemented by cryogenic Ge light detectors allowing us to distinguish alpha from beta/gamma events by the detection of both heat and scintillation light signals. With a bolometric performance of ~ 7 keV energy resolution (FWHM) at 2615 keV, full alpha-to-beta/gamma separation and excellent radio-purity levels, we operate in the background free regime. For the present analysis, we consider more than one year of data acquired between March 2019 and April 2020. With 2.17 kg x yr of exposure and a high analysis efficiency of ~ 90%, we are able to set a new world leading limit for 0νββ decay of 100Mo. In this seminar, I will present the details of the analysis, the new limit and I will conclude with an outlook on the end of CUPID-Mo data taking in July 2020 and further upcoming analyses.
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https://lbnl.zoom.us/j/99340201217?pwd=[REDACTED]
Meeting ID: 993 4020 1217
Password: [REDACTED]

VIRTUAL SEMINAR Special INPA / Research Progress Meeting, Friday, July 17, 2020 – Michelle Galloway (University of Zurich)
2020-07-17 10:00 - 11:00
Speaker: Michelle Galloway (University of Zurich)
Title: Observation of excess electronic recoil events in XENON1T
Abstract: A search for new physics with XENON1T revealed an excess of electronic recoil events in the (1 – 7) keV region, favoring signal over background with significances of 3.5 sigma for solar axions/ALPs, 3.2 sigma for an enhanced neutrino magnetic moment, and 3.0 sigma global (4.0 local) for bosonic dark matter with a peak at 2.3 +- 0.2 keV (68% C.L.). Additionally, a previously undetected tritium component, favoured at 3.2 sigma over known backgrounds, can neither be confirmed nor excluded. I will provide an overview of the XENON1T detection and analysis methods for this search, a characterization of the excess events, and present results for both possible backgrounds and potential new physics.
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https://lbnl.zoom.us/j/98002426771?pwd=[REDACTED]
Meeting ID: 980 0242 6771
Password: [REDACTED]

VIRTUAL INPA SEMINAR – Hao Chen (Texas A&M University)
2020-07-17 12:00 - 13:00
Speaker: Hao Chen (Texas A&M University)
Title: Two New Cryogenic Detector R&D
Abstract: It is well-accepted that the majority of the matter in the universe is dark and non-baryonic. The nature of dark matter, however, remains mysterious. Various proposed candidates span a wide range in the mass and cross section parameter space. Many experimental efforts have been made aiming to detect dark matter particles directly, part of the region in the parameter space has been excluded from their data. Probing the lower mass region requires a low threshold detection technique. I will talk about two new cryogenic detectors that are currently under development. The magnetic bubble chamber utilizes a single-molecule magnet as the target, amplifying the signal from a scattering event by magnetic avalanches. The phonon-mediated high-voltage detector combines features of CDMS iZip and HV detector, provides a possible way to achieve a low threshold without losing the electron recoil/nuclear recoil discrimination.
CORRECTION Updated meeting ID and password information
Join Zoom Meeting https://lbnl.zoom.us/j/96636700595?pwd=[REDACTED]
Meeting ID: 966 3670 0595
Password: [REDACTED]

SPECIAL VIRTUAL INPA SEMINAR – Geertje Heuermann (Karlsruhe Institute of Technology)
2020-07-24 10:00 - 11:00
Speaker: Geertje Heuermann (Karlsruhe Institute of Technology)
Title: Active Shielding for Future Large-Scale Dark Matter Experiments

Abstract: In this talk I will present the conceptual design of a water Cherenkov detector and a loaded liquid scintillator which effectively allow to reduce cosmogenic and radiogenic background sources in tonne scale dark matter detectors.
Join Zoom Meeting https://lbnl.zoom.us/j/94627104366?pwd=[REDACTED]
Meeting ID: 946 2710 4366
Passcode: [REDACTED]

VIRTUAL INPA SEMINAR – Gioacchino Ranucci (INFN) Italy
2020-07-24 12:00 - 13:00
Speaker: Gioacchino Ranucci (INFN) Italy
Title: First detection of solar neutrinos from the CNO cycle with Borexino
Abstract: The liquid scintillator detector Borexino reported recently the direct observation of neutrinos produced in the carbon-nitrogen-oxygen (CNO) fusion cycle in the Sun. This is the first experimental evidence of the existence of such reaction sequence in a star. The CNO solar neutrino interaction rate is 7.2 +3.0 −1.7 counts per day per 100 tons of target at 68% C.L., corresponding to a flux of neutrinos on Earth of 7.0 +3.0 −2.0 ×108 cm−2 s −1. The absence of CNO signal is disfavored at 5.0σ. In this seminar, I will describe the technological effort to stabilize the detector and understand the background, which is at root of this achievement, together with the main features of the analysis procedure exploited to extract the CNO signal.
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https://lbnl.zoom.us/j/96603938296?pwd=[REDACTED]
Meeting ID: 966 0393 8296
Passcode: [REDACTED]

VIRTUAL INPA SEMINAR – Jared Vann (Univ. of Liverpool)
2020-07-31 12:00 - 13:00
Speaker: Jared Vann (University of Liverpool)
Title: ARIADNE: Fast Optical Readout of Dual-Phase LArTPCs with Timepix3 Cameras
Abstract: The ARIADNE experiment is a 1-ton dual-phase LArTPC with a novel optical readout method developed for applications in future Neutrino detectors. Optical readout is a potential alternative to existing charge based readouts in dual phase LArTPCs. The method was first shown to work by the ARIADNE experiment using CCD cameras. Now with extremely fast Timepix3 Cameras we can demonstrate full 3D readout with excellent resolution and calorimetry information.
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https://lbnl.zoom.us/j/92513817972?pwd=[REDACTED]
Meeting ID: 925 1381 7972
Passcode: [REDACTED]

VIRTUAL INPA SEMINAR – Stefan Schoppmann (UC Berkeley)
2020-09-18 12:00 - 13:00
Speaker: Stefan Schoppmann (UC Berkeley)

Title: the STEREO Experiment: Search for Sterile Neutrinos
Abstract: In recent years, two unsolved anomalies have appeared from the study of reactor neutrinos: the reactor antineutrino anomaly being related to the absolute neutrino flux, and the energy spectral shape anomaly. By conducting measurements of reactor neutrinos at very short baselines from a highly enriched uranium reactor, both anomalies can be addressed simultaneously.
STEREO is a liquid-scintintillator-based experiment located at a short ~10 m baseline from the ILL research reactor in Grenoble, France. Its primary objective is the search for energy and baseline dependent disappearance patterns of reactor neutrinos, which would indicate that the reactor antineutrino anomaly could be caused by neutrino oscillations towards sterile neutrinos. Its second objective is to investigate whether highly enriched uranium reactors show the same energy spectral distortions of neutrinos as lowly enriched reactors. Due to the small overburden of 15 m.w.e. and the high ambient neutron flux in the reactor hall, STEREO’s scintillator has to meet special requirements in terms of particle identification and discrimination.
In this presentation, latest results of the STEREO experiment regarding its oscillation, absolute rate, and spectral shape analyses using 179 days of reactor-on data are discussed. A highlight is set on STEREO’s liquid scintillator and its particle ID capabilities.
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https://lbnl.zoom.us/j/99615784061?pwd=[REDACTED]
Meeting ID: 996 1578 4061
Passcode: [REDACTED]

VIRTUAL INPA SEMINAR | Stephane Zsoldos (UCB)
2020-09-25 12:00 - 13:00
Speaker: Stephane Zsoldos (UC Berkeley)
Title: An overview of the Hyper-Kamiokande experiment
Abstract:
Hyper-Kamiokande, which started construction in April 2020, is a next generation underground water Cherenkov detector, based on the highly successful Super-Kamiokande experiment. It will serve as a far detector, 295 km away, of a long baseline neutrino experiment for the upgraded J-PARC beam in Japan. It will also be a detector capable of observing — far beyond the sensitivity of the Super-Kamiokande detector — proton decay, atmospheric neutrinos, and neutrinos from astronomical sources.
Although a wide and rich research program for neutrinos at both low and high-E, I will, after introducing and reviewing the general status of the experiment, focus on the oscillation physics, especially on the two main unanswered questions, the hierarchy of the neutrino mass eigenstates and the value of the leptonic delta CP phase. Especially, I will discuss Hyper-Kamiokande’s sensitivity using a joint atmospheric and accelerator fit to unravel part of these interrogations.
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https://lbnl.zoom.us/j/96424252212?pwd=[REDACTED]
Meeting ID: 964 2425 2212
Passcode: [REDACTED]

VIRTUAL INPA SEMINAR – Adrien Hourlier (MIT)
2020-10-02 12:00 - 13:00
Speaker: Adrien Hourlier (MIT)
Title: MiniBooNE Oscillation Results with Complete Dataset
Abstract:
The MiniBooNE experiment, located on the Booster Neutrino Beamline at Fermilab, reports a total excess of 638.0+/-132.8 electron-like events (4.8σ) from a data sample corresponding to 18.75×10^20 protons-on-target in neutrino mode, which is a 46% increase in the data sample with respect to previously published results, and 11.27 × 10^20 protons-on-target in antineutrino mode. The additional statistics allow several studies to address questions on the source of the excess. I will discuss how we can use distributions such as beam timing and the radial distribution to disfavor some of the possible explanation for the source of the excess such as an excess of entering or exiting photons.
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https://lbnl.zoom.us/j/94852394075?pwd=[REDACTED]
Meeting ID: 948 5239 4075
Passcode: [REDACTED]

VIRTUAL INPA SEMINAR | Scott Kravitz (LBNL)
2020-10-09 12:00 - 13:00
Speaker: Scott Kravitz (LBNL)

Title: CrystaLiZe – Solid Xenon Detector R&D

Abstract:
Radon and its daughter decays limit the sensitivity of direct WIMP dark matter searches, despite extensive screening programs, careful material selection and specialized Rn-reduction systems. For xenon time projection chambers, a means to surpass this constraint may lie in crystallizing the xenon. In a solid matrix, each of the decay steps surrounding the problematic radon daughter beta decay isotopes could be vetoed at the fixed position of the decay sequence. The constraint of time structure in the sequence could allow veto efficiency to approach 100%, with minimal effect on acceptance. In this case, the limiting background for WIMP searches would be neutrinos from the sun and from cosmic ray muons. It is additionally hypothesized that crystalline xenon may offer improved particle discrimination compared with liquid. In this talk, I will argue that an instrumental radon tag in a crystalline xenon TPC may be the quickest path to reaching the neutrino floor and present preliminary results from a test stand which suggest that solid Xe is a viable particle detection medium.

The video for this talk will be posted:
https://physicstalks.lbl.gov/Public/2020/rpm/ScottKravitz0.html

Join Zoom Meeting
https://us04web.zoom.us/j/76619726361?pwd=[REDACTED]

Meeting ID: 766 1972 6361

Passcode: [REDACTED]

VIRTUAL INPA SEMINAR | Kev Abazajian (UC Irvine)
2020-10-16 12:00 - 13:00
Speaker: Kev Abazajian (UC Irvine)

Title: Arising and demising candidate dark matter signals on the sky, and the potential of future searches

Abstract:
New technologies searching are observing the high-energy Universe with unprecedented detail. One of the primary goals of gamma-ray and X-ray astronomy has been the search for potential signals of dark matter that could be at the keV to GeV energy scales. The past 10 years have had two candidate signals in both energy regimes, which are both high energy but separated by a factor of 1 million: the ~3 GeV excess from the Milky Way Galactic Center, and the 3-55 keV line detected in several X-ray observations. I will discuss the saga of these signals and future prospects from the keV to TeV scales.

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https://lbnl.zoom.us/j/93708191260
Meeting ID: 937 0819 1260
Passcode: [REDACTED]

VIRTUAL INPA SEMINAR | Sukanya Chakrabarti (RIT)
2020-10-23 12:00 - 13:00
Speaker: Sukanya Chakrabarti (Rochester Institute Technology)
Title: Measuring Accelerations— Near & Far
Abstract:
Recent technological advances and observational programs now make it possible for us to directly measure the Galactic acceleration experienced by stars within the Milky Way. I will discuss the traditional method of estimating Galactic accelerations and thereby the Oort limit (from which one determines the local dark matter density given the baryon budget), which uses kinematical estimates that can be inaccurate especially in parts of the Galaxy that are significantly perturbed. I will then discuss our method in using extreme precision radial velocity observations to measure the Galactic acceleration, and ongoing observational programs. I will also use compiled pulsar timing data to directly measure the Galactic acceleration, which gives us the Oort limit from the Poisson equation without making assumptions of equilibrium or spherical symmetry (as in kinematic estimates). Given the Oort limit, we then determine the local dark matter density, which has implications for direct detection experiments. I will discuss the potential for measuring dark matter sub-structure in the Milky Way with pulsar timing, and for constraining theories of gravity by combining constraints from pulsar timing and extreme precision radial velocity measurements. Finally, I will end by discussing prospects for measuring the cosmic acceleration.
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https://lbnl.zoom.us/j/93826947056?pwd=[REDACTED]
Meeting ID: 938 2694 7056
Passcode: [REDACTED]

VIRTUAL INPA SEMINAR | Livia Ludhova (RWTH)
2020-10-30 12:00 - 13:00
Speaker: Livia Ludhova (RWTH Aachen/Forschungszentrum Jülich)

Title: JUNO: the first multi-kton liquid scintillator based neutrino detector

Abstract:
The Jiangmen Underground Neutrino Observatory (JUNO) is a neutrino experiment under construction in a 700 m deep underground laboratory near Jiangmen in South China. The detector main component will be 20 kton of liquid scintillator held in a spherical acrylic vessel. The experiment is designed for the determination of the neutrino mass ordering, one of the open key questions in neutrino physics. This measurement will be based on the observation of vacuum oscillation of antineutrinos from two nuclear power plants at 53 km baseline. A key ingredient for the success is an excellent and extremely challenging energy resolution of 3% at 1 MeV. The light produced by the scintillator will be seen by about 20,000 large PMTs (20”) and about 25,000 small PMTs (3”). The OSIRIS detector will monitor the radio-purity of the liquid scintillator during the months-long filling of the main detector, while the unoscillated spectrum from one reactor core is planned to be closely monitored by the Taishan Antineutrino Observatory (TAO). JUNO will also measure several neutrino oscillation parameters with unprecedented sub-percent precision. Astrophysical measurements of solar, geo, supernova, DSNB, atmospheric neutrinos, as well as searches for proton decay or dark matter are also a part of the vast physics programme. The seminar will review the physics goals, design, as well as the status of the JUNO project.

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https://lbnl.zoom.us/j/95227577412?pwd=[REDACTED]
Meeting ID: 952 2757 7412
Passcode: [REDACTED]

VIRTUAL INPA SEMINAR | Julieta Gruszko (UNCCH)
2020-11-06 12:00 - 13:00
Speaker: Julieta Gruszko (University of North Carolina at Chapel Hill)
Title: Shedding ‘Nu’ Light on the Nature of Matter: NuDot and the Search for Majorana Neutrinos

Abstract:
Why is the universe dominated by matter, and not antimatter? Neutrinos, with their changing flavors and tiny masses, could provide an answer. If the neutrino is its own antiparticle, it would reveal the origin of the neutrino’s mass, demonstrate that lepton number is not a conserved symmetry of nature, and provide a path to leptogenesis in the early universe. To discover whether this is the case, we must search for neutrinoless double-beta decay. As the upcoming ton-scale generation of experiments is built, it is key that research and development (R&D) efforts continue to explore how to extend experimental sensitivities to 10^29 years and beyond. These next-next-generation experiments could make a discovery, if neutrinoless double-beta decay is not found at the ton-scale, or offer insight into the mechanism behind lepton number violation, if it is. NuDot is a proof-of-concept liquid scintillator experiment that will explore new techniques for isotope loading and background rejection infuture detectors. I’ll discuss the progress we’ve already made in demonstrating how previously-ignored Cherenkov light signals can help us distinguish signal from background, and the technologies we’re developing with an eye towards the coming generations of experiments.
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https://lbnl.zoom.us/j/91339017890?pwd=[REDACTED]
Meeting ID: 913 3901 7890
Passcode: [REDACTED]
Abstract: https://inpa.lbl.gov/2020/11/02/virtual-inpa-sem…ta-gruszko-uncch/

VIRTUAL INPA SEMINAR | Tomi Akindele (LLNL)
2020-11-13 12:00 - 13:00
Speaker: Tomi Akindele (Lawrence Livermore National Laboratory)
Title: Antineutrinos as a Nuclear Safeguards Tool
Abstract:
To date, antineutrino experiments built for the purpose of demonstrating a nonproliferation capability have typically employed organic scintillator, and been situated as close to the core as possible – typically a few meters to tens of meters distant, and have not exceeded a few tons in size.
One problem with this approach is that proximity to the reactor core requires accommodation by the host facility. Water Cherenkov detectors located offsite, at distances of a few kilometers or greater, may facilitate non-intrusive monitoring and verification of reactor activities over a large area.
As the standoff distance increases, the detector target mass must scale accordingly. This talk quantifies the degree to which a kiloton-scale gadolinium-doped water Cherenkov detector can exclude the existence of undeclared reactors within a specified radial distance, and remotely detect the presence of a hidden reactor in the presence of declared reactors, by verifying the operational power and standoff distance.
A Feldman-Cousins based likelihood analysis was used to quantify the detector’s ability to exclude the existence of undeclared reactors. A 1-kton scale Water Cherenkov detector can exclude gigawatt-scale nuclear reactors up to tens of kilometers. When attempting to identify the specific location of a reactor, the detector response and analysis cannot delineate between the reactor power and baseline.
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https://lbnl.zoom.us/j/97530987599?pwd=[REDACTED]
Meeting ID: 975 3098 7599
Passcode: [REDACTED]
Abstract: https://inpa.lbl.gov/event/virtual-inpa-seminar-tomi-akindele-llnl/

Special Double feature Virtual INPA seminar | Anton Baleato Lizancos (Cambridge) and Utkarsh Giri (PITP)
2020-11-20 10:00 - 11:00
Speaker: Anton Baleato Lizancos (Cambridge)
Title: “Understanding biases to CMB lensing and delensing on the road to precision science”
Abstract: For cosmologists, CMB lensing can be both a blessing and a nuisance. It’s a nuisance because it generates spurious B-mode polarisation which obscures the highly-sought-after signal from inflationary gravitational waves, but it’s a blessing because it can be used to reconstruct maps of the projected matter distribution of the Universe, from which any physics affecting the growth of cosmic structure can be constrained. In this talk, I will focus on systematics that need to be addressed in order to harness the full statistical power of upcoming CMB experiments and make progress in both of these exciting areas. In the first part of my talk, I will briefly review the ways in which extragalactic emission from galaxies and clusters can bias CMB lensing reconstruction power spectra and cross-correlations with other tracers of the matter distribution. I will then present ongoing work on a novel approach where we model these biases analytically as a function of experimental characteristics, enabling improved physical insight, a quantification of theoretical uncertainties and potentially opening the door to improved mitigation methods. In the second part of the talk, I will explain how the lensing contamination to CMB B-modes can be removed — what is known as delensing — in order to facilitate searches for inflationary gravitational waves, and describe limitations of the commonly-used “template” approach to delensing. I will then briefly summarize preparatory efforts to delens data from the upcoming Simons Observatory. Finally, I will conclude by discussing biases affecting the procedure (and how to mitigate them) when lensing is reconstructed internally from the CMB itself, and in the alternative scenario where the CIB is used as a tracer of the matter.
Speaker: Utkarsh Giri (Perimeter Institute of Theoretical Physics)
Title: “Exploring kSZ velocity reconstruction with N-body simulations and the halo model”
Abstract:
KSZ velocity reconstruction is a recently proposed method for mapping the largest-scale modes of the universe, by applying a quadratic estimator v̂ to the small-scale CMB and a galaxy catalog. We implement kSZ velocity reconstruction in an N-body simulation pipeline and explore its properties. We find that the reconstruction noise can be larger than the analytic prediction which is usually assumed. We revisit the analytic prediction and find additional noise terms that explain the discrepancy. The new terms are obtained from a six-point halo model calculation, and are analogous to the N(1) and N(3/2) biases in CMB lensing. We implement an MCMC pipeline which estimates fNL from N-body kSZ simulations and show that it recovers unbiased estimates of fNL, with statistical errors consistent with a Fisher matrix forecast. Overall, these results confirm that kSZ velocity reconstruction will be a powerful probe of cosmology in the near future, but new terms should be included in the noise power spectrum.
Join Zoom Meeting: https://lbnl.zoom.us/j/97706913102?pwd=[REDACTED]
Meeting ID: 977 0691 3102
Passcode: [REDACTED] 505782
Abstract: https://inpa.lbl.gov/event/special-double-f…tkarsh-giri-pitp/

VIRTUAL INPA SEMINAR | Liang Dai (UCB)
2020-11-20 12:00 - 13:00
Speaker: Liang Dai (UC Berkeley)
Title: A New Window Into the Universe: Gravitational Waves From Compact Binary Coalescence
Abstract:
Detection of chirping gravitational waves (GWs) at ground-based laser interferometry observatories LIGO and Virgo have uncovered a population of compact binary mergers. Forthcoming observing runs with upgraded sensitivity and more observatories joining the network will tremendously increase the number of source systems, which will shed light on their astrophysical origin and enable to exploit those events as cosmological probes. I will present independent efforts by the IAS group to analyze the publicly available LIGO/Virgo data and report newly discovered GW events in addition to what experimental collaborations have reported. I will highlight several original and crucial data analysis methodologies we have developed for template matching, noise characterization and parameter estimation. In addition, I will give outlook on gravitational lensing of cosmological GW sources as expected from forthcoming observations and envisage its applications. I will explain our new findings of how wave propagation effects, measurable with GWs but unfeasible with usual electromagnetic sources, can allow extraction of unique information to reconstruct the lens or to probe non-luminous sub-galactic dark matter structures, thereby deepening our understanding of the matter distribution in the Universe.
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Meeting ID: 957 5750 2382
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VIRTUAL INPA SEMINAR | Tongyan Lin (UCSD)
2020-12-04 12:00 - 13:00
Speaker: Tongyan Lin (UC San Diego)
Title: Direct Detection of Sub-GeV Dark Matter with the Migdal Effect in Semiconductors
Abstract:
As direct detection experiments expand the search for sub-GeV dark matter and lower their energy thresholds, the many-body physics of crystals can be increasingly important and also be used to enhance discovery potential. In this talk, I will discuss the Migdal effect in semiconductors, which is the creation of charge signals from inelastic dark matter-nucleus scattering. The Migdal effect has previously been studied in atomic targets, and used to set limits in liquid Xe experiments. Because of the smaller gap for electron excitations, we find that the rate for the Migdal effect is much higher in semiconductors, and accounting for it can significantly improve the reach of experiments.
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Meeting ID: 921 4749 7949
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VIRTUAL INPA SEMINAR | Elena Gramellini (Fermilab)
2020-12-11 12:00 - 13:00
Speaker: ​Elena Gramellini (​Fermilab)
Title: Seeing the ​L​ight in ​P​ixelated TPCs: Q-Pix and LILAr
Abstract:
Noble elements Time Projection Chambers (TPC) are the detector technology of choice for the next generation of discovery at the intensity frontier. These detectors provide a number of experimental handles, such as full 3D-imaging, excellent particle identification and precise calorimetric energy reconstruction which makes them extremely flexible tools suitable for a wide range of physics measurements. Indeed, TPC applications range from dark matter, rare decays and capture, neutrino oscillations and nucleon decay, and neutrino less double beta decay. A key feature of noble elements for particle detectors is the double response to the passage of charged particles in the active volume, in the form of correlated ionization charge and scintillation light.
In the context of the Deep Underground Neutrino Experiment (DUNE), the liquid argon community is showing great interest in developing a large scale pixelated charge readout for multi-kTon scale detectors. Pixels offer a number of benefits compared to the traditional 2D projective wire readout, ranging from the robustness against single point failure to the native 3D nature of the data. However, a light detection solution which would allow the full exploitation of the detection capabilities for pixelated TPCs needs to be developed: the solutions used in traditional 2D wires projective readouts are not satisfactory (nor easily applicable). In this seminar, we present Q-Pix — the technology which could translate pixelated readout into a reality for multi-kTon scale TPCs — and LILAr — an imaginative idea for light detection systems in pixelated TPCs.
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Meeting ID: 942 7291 8445
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VIRTUAL INPA SEMINAR | Patrick Komiske (MIT)
2020-12-18 12:00 - 13:00
Speaker: Patrick Komiske (MIT)
Title: Optimizing Particle Physics With Machine Learning
Abstract:
Exciting new advances in particle physics, particularly in the area of jet physics at colliders such as the LHC, are being driven by machine learning (ML) methods. For example, in just a few short years, the state of the art for important tasks such as jet classification has progressed from cutting on single observables to hyper-variate classifiers that can be trained directly on data. In this talk, I will discuss these and other developments that demonstrate broad synergy between ML and particle physics, including training and calibrating jet classifiers directly on data, visualizing and quantifying jets from the CMS Open Data with a recently proposed metric between collider events, and simultaneously unfolding multiple observables with the OmniFold method.
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https://lbnl.zoom.us/j/96028254060?pwd=[REDACTED]
Meeting ID: 960 2825 4060
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VIRTUAL INPA SEMINAR | Kelly Stifter (Stanford)
2021-01-08 12:00 - 13:00
Speaker: Kelly Stifter (Stanford University)
Title: The LZ Dark Matter Experiment: From Detector Development to First Physics
Abstract:
LZ is a next generation dark matter search designed to significantly extend our sensitivity to WIMP dark matter candidates. At the core of the LZ experiment is a dual-phase xenon time projection chamber (TPC) with a 7 ton active mass. The detector has been assembled at the Sanford Underground Research Facility (SURF) in Lead, South Dakota and is now in the commissioning phase. After 1000 days of live time, LZ will achieve a sensitivity of about 1.4 x 10-48 cm2 at 40 GeV/c2 WIMP mass, improving on previous results by over an order of magnitude. In this talk, I will give an overview of the development, construction, and current commissioning status of the experiment, focusing in particular on the liquid xenon detector at the core of LZ. I will highlight the design and implementation of key features that drive the sensitivity of the experiment, including scintillation and ionization detection thresholds and control of backgrounds.

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Meeting ID: 932 9395 0850
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Virtual INPA SEMINAR| Nguyen Phan (LANL)
2021-01-15 10:00 - 11:00
Speaker: Nguyen Phan (Los Alamos National Laboratory)
Title: “Understanding Electrical Breakdown in Liquid Helium through Analysis of the Empirical Breakdown Field Distributions”
Abstract:
Many present and future large-scale detectors in nuclear, particle, and astroparticle physics experiments will employ very high voltages and/or high electric fields inside a noble liquid detection medium. However, electrical breakdown in these dielectric materials is still poorly understood and may pose a challenge to the design and operation of such experiments. The neutron electric dipole moment (nEDM) experiment currently being developed to be mounted at the Spallation Neutron Source (SNS) at Oak Ridge National Laboratory will perform its measurements in superfluid helium with a target field of 75 kV/cm. Vital to achieving such a high field at large-scale is a better understanding of the breakdown phenomenon. To that end, we have collected data on the distribution of the breakdown voltages for small stainless steel electrodes with different surface polishes immersed in liquid helium, at various temperature and pressures, with the goal of providing guidance on the design of the high voltage system for the nEDM experiment at SNS, but also with potential application to other noble liquid experiments. In this talk, we will show how a statistical analysis of our data can be used to determine the electrode surface area scaling of the breakdown field, a behavior that is of central importance to the design of large-scale detectors employing high voltage. We will show that the dependence of the probability of breakdown on the field strength, extracted from the data, closely resembles that of the field emission, giving a strong indication that the initial process involves the field emission from the cathode. A method to optimize the design of arbitrary-shaped electrodes to reduce the risk of breakdown is also presented. Most importantly, the methods proposed in this work can be extended to other noble liquids to explore the behavior of electrical breakdown in those media.
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Meeting ID: 937 5807 0002
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