Physics and Astronomy Calendar

Week of Monday, February 18th 2019

Monday, February 18th 2019
12:15 pm:
Speaker: TBD
3:35 pm:
Speaker: David Caratelli (FNAL)
Subject: Neutrinos in High Definition

Thanks to advances in detector technology and the advent of powerful neutrino sources, neutrino physics in the past decade has rapidly moved to an era of precision measurements. With these new tools, we hope to shed light on their curious properties, and address fundamental questions on the fabric of our universe. In this seminar I will talk about how the MicroBooNE experiment is using a new detector technology to understand an anomaly in neutrino physics that has motivated many interesting phenomenological models. The talk will describe the MicroBooNE experiment, a short-baseline neutrino detector sitting in a ~1 GeV beam, and the status of the measurement of electron neutrino
interactions. I will focus on illustrating how the study of electromagnetic activity in LArTPC detectors enables MicroBooNE’s study of electron neutrino interactions as well as the broader neutrino oscillation physics program to be carried out at Femilab. Finally, I will describe how low-energy electromagnetic signatures can expand this detector technology’s physics reach to explore BSM physics and astrophysical signatures.

Tuesday, February 19th 2019
1:25 pm:
Space Physics Seminar in Tate 301-20
Speaker: Cynthia Cattell and Chris Colpitts
Subject: Wave generation by relativistic electron beams in a plasma: Initial results fromLAPD run
There will be no seminar this week.

Wednesday, February 20th 2019
1:25 pm:
Speaker: Boris Spivak, University of Washington
Subject: Magneto-transport phenomena related to the chiral anomaly in Weyl and Dirac semimetals

I will present a theory of magnetotransport phenomena related to the chiral anomaly in Weyl semimetals. I will show that conductivity, thermal conductivity, thermoelectric and the sound absorption coefficients exhibit strong and anisotropic magnetic field dependences. I will also discuss properties of magneto-plasmons and magneto-polaritons, whose existence is entirely determined by the chiral anomaly.

Faculty Host: Boris Shklovskii
Speaker: Nadja Strobbe (FNAL)
Subject: Taking aim at New Physics

The Standard Model of Particle Physics has been immensely successful. However, many questions remain, such as the nature of dark matter, the origin of the matter-antimatter asymmetry, and the question of naturalness and the hierarchy problem. A variety of New Physics models have been proposed to address these questions. One class of such new physics models is supersymmetry (SUSY).

Many searches for SUSY have been performed with the LHC data, and so far, none has found any signs of physics beyond the Standard Model. A theme common to many of these searches is the reliance on the presence of substantial missing transverse momentum (MET) from undetected SUSY particles. It is therefore reasonable to wonder whether SUSY could take a form that instead produces low-MET final states, thereby evading detection in standard searches.

In this seminar I will first discuss the motivation and strategy behind some of the traditional SUSY searches, focusing in particular on searches for the top squark. Then, I will introduce SUSY models that lead to low-MET final states, including stealth SUSY and R-parity violating SUSY. I will describe a novel analysis that takes aim at the challenging final state with top quarks, many extra jets, and low MET. Finally, I will conclude with a look towards the future, including HL-LHC projections for SUSY searches.

Thursday, February 21st 2019
10:10 am:
Biophysics Seminar in 120 PAN
Speaker: Gordon Smith, Assistant Professor, Department of Neuroscience, UMN
Subject: Development of large-scale networks in visual cortex.

Sensory perception requires the coordinated activity of tens of thousands of neurons, working together in large-scale networks. As developmental events define and constrain the ultimate capabilities of these networks, it is therefore essential to understand the mechanisms underlying their formation. This talk will present recent work showing that in the developing visual cortex, correlations in spontaneous neural activity define large-scale functional networks with precise local and long-range organization that span millimeters of cortical area. These early networks predict future stimulus-evoked activity well before it can be visually driven, suggesting they form a substrate for building a mature large-scale functional architecture.

12:10 pm:
Speaker: Grantland Hall and Pat Kelly
3:30 pm:
Special Public Lecture in Best Buy Theater, Northrop, University of Minnesota
Speaker: Roger Launius, Chief Historian for NASA and Senior Curator of the Smithsonian Air and Space Museum (retired)
Subject: Why Go to the Moon? Apollo, the Space Race, and the Many Faces of Lunar Exploration
3:35 pm:
Physics and Astronomy Colloquium in Physics Tate B50
Speaker: Flavio Cavanna, Yale
Subject: Lifting the lid on DUNE, the new international mega-science project in the US

The experimental discoveries of the last half century have placed neutrinos in the spotlight to unlock the mysteries of the matter's abundance unbalance in the Universe and of the ultimate fate of the stars. The lack of direct observations of proton decays, on the other hand, keeps at bay the dream that the forces of nature were unified at the beginning of time.
The Deep Underground Neutrino Experiment (DUNE) is the new leading-edge, international mega-science experiment for neutrino science and proton decay search.
DUNE will consist of two paired neutrino detectors placed in the world’s most intense neutrino beam. One massive detector will be installed deep underground at the SURF laboratory, in South Dakota — 1,300 kilometers away from FERMILAB, where the second detector will be positioned just downstream the neutrino source. Detecting the energetic beam neutrinos at the far site and comparing with those detected at the near site can give insight about our matter dominated universe. The underground location of the far detector, screened from the overwhelming cosmic ray flow, may allow to detect tiny signals from neutrinos originated by a core-collapse supernova in the Milky Way and thus possibly peer inside a newly-formed neutron star. And finally, the extra-large amount of mass of the detector may allow primordial symmetries to occasionally resurface inside a proton and spontaneously morphing a quark into a lepton, with the proton instantly falling apart into a detectable flash of radiation.
But not only large mass and far distance matter to pursue this ambitious discovery plan: unprecedented detection technologies and a worldwide effort to build the detector are required. DUNE will use the state-of-the-art Liquid Argon TPC technology to instrument deep underground 70.000 tons of Liquid Argon at 87K, with millimeter scale 3D precision.
A 1 kTon precursor of the far LAr-TPC detector has been constructed and recently activated at the CERN Neutrino Platform, and is now taking data. A first look of the spectacular events collected will be shown.

Faculty Host: Roger Rusack

Friday, February 22nd 2019
11:00 am:
Nuclear Physics Seminar in Tate 301-20
Speaker: Tom Welle, University of Minnesota
Subject: To be announced.
12:20 pm:
Speaker: Xiaojun Fu
Subject: Broken symmetry states in the N = 3 Landau level of GaAs quantum wells with alloy disorder
12:30 pm:
High Energy Theory Lunchtime Seminar in Tate 110 (note location change for this week)
Speaker: Radu Roiban (Penn State)
2:30 pm:
Speaker: Anna Williams, Macalester University
Subject: Exploring the coevolution of magnetic fields and galaxies in different environments

Galaxies are permeated with magnetic fields at all scale lengths--from protostellar disks to spiral arms. But how galaxies first acquired magnetic fields, and, in turn grow and sustain large-scale magnetic structures is not well understood. One way to unravel this problem is by observing magnetic fields in a variety of galaxy environments. Luckily, new and upgraded radio telescopes are providing a new window to the polarization universe, and greatly enhancing our ability to probe astrophysical magnetic fields. I will present the results of three observational studies focused on the coevolution of magnetic fields and galaxies in different environments: (1) a nearby spiral galaxy, NGC 6946, (2) a loose galaxy group, NGC 2563, and (3) distant disk-like galaxies at z~0.5.

Speaker: Michael Gordin, History - Princeton University
Subject: Einstein in Bohemia: Science and Prague before and after the Habsburgs
Refreshments served at 3:15 p.m.
3:35 pm:
There will be no seminar this week.
Speaker:  Carolyn Bishoff, UMN Libraries

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