Fermilab colloquium calendar archive 2021

  Appropriate for physicists     Appropriate for all lab staff and members of the public
Raw date Event date Title Speakers Host Summary Links
20210106 Jan. 6, 2021 No colloquium
20210113 Jan. 13, 2021 Open
20210120 Jan. 20, 2021 Open
20210127 Jan. 27, 2021 Open
20210203 Feb. 3, 2021 Open
20210210 Feb. 10, 2021 Open
20210217 Feb. 17, 2021
Quantum Squeezing and Quantum Correlations in advanced LIGO
Lee McCuller, Massachusetts Institute of Technology and the LIGO Laboratory Chris Stoughton Optical interferometers have begun a new era of astrophysics by measuring length to such precision that gravitational waves (GW) from distant collisions of black holes and neutron stars are now regularly observed. This past observing run, the global GW observatory network itself entered a new era, whereby every detector's sensitivity is enhanced using quantum squeezed states of light. This talk examines the implementation of squeezing in the Laser Interferometer Gravitational-Wave Observatory (LIGO), detailing how measurement back action affects the 40kg mirrors of LIGO in the form of quantum radiation pressure noise and how squeezing allows us to reduce back action using quantum correlations between the light and mirrors. LIGO plans to yet improve on squeezing with future upgrades to not only improve squeezed state quality, but also to install a quantum filter cavity so both imprecision and back-action are reduced in LIGO at the same time. video
20210224 Feb. 24, 2021
Zeolite water purification at Tikal, an ancient Maya city in Guatemala
Kenneth Barnett Tankersley, Ph.D. (Piqua Tribe of Alabama), University of Cincinnati Chris Stoughton Evidence for the oldest known zeolite water purification filtration system occurs in the undisturbed sediments of the Corriental reservoir at the Maya city of Tikal, in northern Guatemala. The Corriental reservoir was an important source of drinking water at Tikal during the Late Preclassic to Late Classic cultural periods. X-ray diffraction analysis (XRD) and six AMS radiocarbon ages show that between ~ 2185 and 965 cal yr B.P. the drinking water in the Corriental reservoir water was filtered through a mixture of zeolite and coarse, sand-sized crystalline quartz. Zeolite is a non-toxic, threedimensionally porous, crystalline, hydrated aluminosilicate with natural adsorbent and ion exchange properties, which removes harmful microbes as well as dispersed insoluble and soluble toxins from drinking water. The occurrence of zeolite in Corriental reservoir sediments expands our understanding of the earliest history of water purification and the long-term sustainability of an ancient Maya city. Video
20210303 March 3, 2021 Open
20210310 March 10, 2021 Open
20210317 March 17, 2021
There are particles in my whiskey! (The science of whiskey colloids)
Stuart Williams, University of Louisville Dan Hooper Suspended particles, also known as colloids, form when you dilute whiskey with water and/or chill it. This phenomenon has been observed by whiskey distillers for years, typically during filtration or quality control. Our research investigates the formation of these whiskey colloids and how they influence surface tension and form chemical monolayers on the interface of microdroplets. During evaporation these monolayers collapse and form patterns unique to each brand of whiskey, which may be used for counterfeit identification. Further, this mechanisms seems to be unique to American whiskey which is characterized by being matured in new charred oak barrels. This presentation will introduce the basic science of bourbon whiskey, characterization of whiskey colloids, and how “whiskey webs” form during droplet evaporation. Video
20210324 March 24, 2021 Open
20210331 March 31, 2021 Open
20210407 April 7, 2021 Open
20210414 April 14, 2021
A no-lose theorem for discovering the new physics of (g-2)
David Curtin, University of Toronto Dan Hooper Recent measurements by the Fermilab g-2 experiment seem to confirm the long-standing muon g-2 anomaly first measured by BNL. If theoretical and experimental progress in the coming years confirms the deviation from the Standard Model (SM) expectation, this would represent the first solid evidence of Beyond SM (BSM) physics. Over the years, many models have been proposed to account for the g-2 anomaly, but we ask a simple question: how heavy could the new physics be, based only on unitarity and optionally general flavour or naturalness considerations? We perform a model-exhaustive analysis of all possible BSM solutions to the anomaly and analyze their phenomenology. Our results show that a muon physics program starting with a low-energy fixed target experiment and culminating in a  30 TeV muon collider is guaranteed to discover new physics connected to g-2. video
20210421 April 21, 2021 Open
20210428 April 28, 2021 Open
20210505 May 5, 2021 Open
20210512 May 12, 2021 Open
20210519 May 19, 2021 Open
20210526 May 26, 2021 Open
20210602 June 2, 2021
Nanotechnology for Flat optics: from metalenses to new cameras
Federico Capasso, Harvard Chris Stoughton Nanotechnology enables the redesign of optical components into thin, and planar elements with much easier control of aberrations than conventional optics, ease of optical alignment as well as the introduction of a new class of multifunctional devices, with a concomitant major reduction in footprint and complexity. The planarity of flat optics will lead to the unification of semiconductor and optics manufacturing, where the planar technology to manufacture computer chips will be adapted to make CMOS-compatible metalenses for cell phones, wearable displays, new cameras as well as wide range of multifunctional devices. Video
20210609 June 9, 2021
Lattice QCD: from Promise to Precision
Andreas Kronfeld, Fermilab Chris Stoughton Within the Standard Model of particle physics, quantum chromodynamics (QCD, the theory of the strong force) is unique in several ways. It is a beautiful quantum field theory, consistent at all energies, all temperatures, and all densities. It is rich in emergent phenomena, which is a more challenging kind of beauty when quantitative understanding is needed. By now, however, several “incalculable” QCD properties have been calculated with sub-percent precision, thanks to numerical lattice gauge theory. In this colloquium, I trace this subject’s journey from a promising technique to a precise and predictive tool, relied on to interpret experiments in particle physics, nuclear physics, and even astrophysics. Video
20210616 June 16, 2021
Single-molecule detection and identification via DNA nanotechnology
William Shih, Harvard Chris Stoughton DNA origami, in which a long scaffold strand is assembled with a large number of short staple strands into parallel arrays of double helices, has proven a powerful method for custom nanofabrication of shapes up to 100 nm in size. However, the scaffold represents about half the mass of an origami, therefore the origami size is restricted by the length of the scaffold. Furthermore, it is impractical and prohibitively expensive to scale the length of the scaffold. Here I will discuss a strategy, that we call crisscross ultracooperative assembly, that combines all-or-nothing scaffold-dependent initiation of folding with scaffold-independent growth, therefore allowing for sizes unbounded by the length of the scaffold. A major application will be digital counting of molecular analytes, where each molecular detection event triggers growth of a single filament resolvable by low-cost microscopy.
20210623 June 23, 2021 Open
20210630 June 30, 2021 Open
20210707 July 7, 2021 Open
20210714 July 14, 2021 Open
20210721 July 21, 2021 Open
20210728 July 28, 2021 Open
20210804 Aug. 4, 2021 Users Meeting - No colloquium
20210811 Aug. 11, 2021 Open
20210818 Aug. 18, 2021 Open
20210825 Aug. 25, 2021 Open
20210901 Sept. 1, 2021
“The risk of nuclear war and how physicists, acting as citizen-scientists, can help reduce it.”
Frank von Hippel, Princeton University Chris Stoughton   When: Wednesday, September 1, 2021 at 4:00 PM – 5:00 PM. Location: ZOOM ONLY   Please contact Barb Kronkow at kronkow@fnal.gov for the zoom link The end of the Cold War reduced fears in the US and Russia that the other might deliberately mount a nuclear attack. The two countries still maintain their hair-trigger... More » Video
20210908 Sept. 8, 2021 Open
20210915 Sept. 15, 2021
Stellar Basins of Gravitationally Bound Particles
Ken Van Tilburg, New York University Dan Hooper Explore the consequences of a newly identified physical phenomenon: volumetric stellar emission into gravitationally bound orbits of weakly coupled particles such as axions, moduli, hidden photons, and fermions. While only a tiny fraction of the instantaneous luminosity of a star (the vast majority of the emission is into relativistic modes), the continual injection of these particles into a small part of phase space causes them to accumulate over astrophysically long time scales, forming what I call a "stellar basin", in analogy with the geologic kind. The energy density of the Solar basin can surpass that of the relativistic Solar flux at Earth's location after only a million years, for a sufficiently long-lived particle produced through an emission process whose matrix elements are unsuppressed at low momentum. This observation has immediate and striking consequences for direct detection experiments---including new limits on axion and hidden-photon parameter space independent of dark matter assumptions. I will discuss ongoing N-body simulations of the Solar basin, and preliminary results on indirect detection of basin particles around the Sun and other stars.
20210922 Sept. 22, 2021 Open
20210929 Sept. 29, 2021 Open
20211006 Oct. 6, 2021 Open
20211013 Oct. 13, 2021 No colloquium
20211020 Oct. 20, 2021 No colloquium
20211027 Oct. 27, 2021 No colloquium
20211103 Nov. 3, 2021 No colloquium
20211110 Nov. 10, 2021 No colloquium
20211117 Nov. 17, 2021 No colloquium
20211124 Nov. 24, 2021 No colloquium
20211201 Dec. 1, 2021 No colloquium
20211208 Dec. 8, 2021 No colloquium
20211215 Dec. 15, 2021 No colloquium
20211222 Dec. 22, 2021 No colloquium
20211229 Dec. 29, 2021 No colloquium