Physics and Astronomy Colloquia, Academic Year 2019-2020

Colloquium committee: Marivi Fernandez-Serra (Chair), Will Farr, Dmitri Kharzeev, Rouven Essig and Giacinto Piacquadio


Coffee & Tea served at 3:45 pm.

Talk begins at 4:15 pm.

Location: Harriman 137 (bottom of square C4 on the campus map)

Movies:  To watch the recorded movies, please  read the instructions here.

 

Fall 2019 colloquia


Sept. 3

Chair’s Colloquium


Chair’s Colloquium
   [recorded movies]
   VLC:
rtsp://www.physics.sunysb.edu:5554/chair-090319

Sept. 10

Dan Mckinsey

University of Berkeley

From Liquid Xenon to Superfluid Helium: Dark Matter Direct Detection with Noble Liquids

Noble liquids have proven high effective in the search for interactions of dark matter with ordinary matter. This is due to their intrinsic scalability, low backgrounds, straightforward purification, and copious signal carriers. The LUX (Large Underground Xenon) experiment was a dual-phase (liquid/gas) xenon time projection chamber with an active mass of 250 kg that operated at the Sanford Underground Research Facility (SURF) from 2013 until 2016. Its main objective was to look for evidence of galactic dark matter in the form of Weakly Interacting Massive Particles (WIMPs). I will report the most recent LUX results from several new data analyses such as searches for axions, axion-like particles, low-mass dark matter interactions, and rate modulation in the data. I will also present recent calibration studies of the ionization and scintillation response of liquid xenon, such as pulse shape discrimination, electronic recoil calibrations using 83mKr, 127Xe, and 14C, and nuclear recoil calibration using a pulsed D–D neutron generator. These calibrations are essential to the development of the next generation of dark matter detectors, such as the LUX-ZEPLIN (LZ) experiment which is currently being assembled at the Sanford Underground Research Facility. I will present the design, current status, and projected scientific performance of LZ, which is expected to begin underground operations in 2020.            Finally, I will describe a method to search for low-mass dark matter particles using superfluid helium., dubbed HeRALD. Because the helium nucleus is relatively low in mass, it has good kinematic matching to low-mass dark matter particles. Also, because helium is liquid down to absolute zero, this enables an easily purified target material in which extremely small energy depositions may be detected using low-temperature calorimetric devices such as transition edge sensors. This method is intrinsically scalable to large target masses, and background rejection may be achieved using information carried from the interaction site by photons, phonons, and rotons.
  [recorded movies]  


Sept. 17

Mengkun Liu

Stony Brook University

IR and THz nano-imaging and nano-spectroscopy of strongly correlated electron materials

Over the past decade, optical near-field techniques, especially the scattering-type scanning near-field optical microscopes (s-SNOM), have undergone tremendous development. This is partly due to the ever-increasing demand for the exploration of the nano-world and partly due to the many technical advances in laser and scanning probe technologies. I will use this opportunity to report the recent advances in the infrared (IR) and terahertz (THz) near-field nanoscopy and spectroscopy technology and discuss their applications in strongly correlated electron materials. I will also report on how to extract complex dielectric constants at a length scale far below the optical diffraction limit and discuss the future development of s-SNOM, which includes the cryogenic and ultrafast pump-probe capabilities. These new developments set the stage for future spectroscopic investigations to access the low energy electron, phonon, and spin dynamics in complex quantum materials at the nanoscale.
  [recorded movies]  


Sept. 24

Chris Rasmussen

CERN

Using Trapped Antihydrogen to Probe Fundamental Symmetries

Antihydrogen - the antimatter equivalent the ordinary hydrogen atom - offers a unique way of probing fundamental symmetries. In particular, CPT symmetry (Charge, Parity and Time) requires that the spectrum of antihydrogen be identical to that of its ordinary matter cousin. In the ALPHA experiment at CERN, antihydrogen atoms are synthesized and magnetically trapped to enable spectroscopic measurements and subsequent comparison to the hydrogen spectrum. Of particular interest is the 1S-2S transition, which, due to its very narrow natural line width, allows for a particularly high precision test of CPT symmetry. Our best measurement of this transition frequency thus far has a relative error of just 2 parts in a trillion, making it one of the most precise measurements performed on an antimatter system. Antimatter gravity is another topic of growing interest, with several experiments aiming to make a first observation of the free-fall acceleration of antimatter. ALPHA-g is a new experiment which aims to measure this acceleration through the careful release of magnetically trapped antihydrogen atoms, eventually reaching a precision of around 1%. In this talk I will present the state-of-the art in antihydrogen physics and outline some of the measurements that will be possible in the near future.
  [recorded movies]  


Oct. 1

Derek Teaney

Stony Brook University

Heavy ion collisions: the kinetics of gauge theories at work

I will first review several characteristic measurements from the Relativistic Heavy Ion Collider (RHIC) and the Large Hadron Collider (LHC), which together give overwhelming evidence for collective hydrodynamic behavior in nucleus-nucleus collisions. Challenging measurements on proton-nucleus collisions will also be discussed. I then will describe the kinetic processes that go on in the quark-gluon plasma, at least in the limit of weak coupling. These kinetic processes include many features such as collinear radiation and non-abelian plasma screening that are unique to QCD and high temperature gauge theories more generally. Finally, I will describe how the kinetic equations can be used to understand the approach to hydrodynamics at late times, and estimate when the hydrodynamic description should break down as a function of event multiplicity. The limitations of the kinetic approach, which is ultimately based on weak coupling, will also be briefly discussed.
  [recorded movies]  


Oct. 8

Josh Ruderman

NYU

Phases of Particle Dark Matter

Dark matter is believed to make up most of the matter in our Universe, but its particle origin remains a mystery. A favorite candidate is the so-called Weakly Interacting Massive Particle (WIMP), but a diverse set of experiments are rapidly closing the available parameter space for WIMPs. I will show that small changes to the assumptions about how dark matter was produced in the early Universe lead to very different dark matter masses. I will chart a ``phase diagram” for the production of dark matter in the early Universe, and will explain how different phases map onto different experimental prospects.
  [recorded movies]  


Oct. 22

Gabor Balazsi

Laufer Center, Stony Brook University

Physical principles from evolutionary synthetic biology.

Synthetic biology is a new scientific field that designs and builds artificial biological systems, using principles from engineering, mathematics and physics. Existing achievements include massive, low-cost drug synthesis, and the construction of genetic switches, oscillators and logic gates. In my laboratory we develop new genetic control knobs (synthetic gene circuits) to command genes and then watch how the cells respond. This way, we hope to extract physical principles underlying cellular evolution, while developing a predictive, quantitative understanding of biological processes relevant to drug resistance and cancer progression. I will present a couple of examples of how we can gain a deeper understanding of evolutionary processes using synthetic gene circuits.
  [recorded movies]  


Oct. 29

Giuseppe Carleo

CCQ, Flatiron Institute

Machine learning many-body quantum physics

Machine-learning-based approaches, routinely adopted in cutting-edge industrial applications, are being increasingly embraced to study fundamental problems in science. Many-body physics is very much at the forefront of these exciting developments, given its intrinsic "big-data" nature. In this seminar I will present selected applications to the quantum realm. First, I will discuss how a systematic, and controlled machine learning of the many-body wave-function can be realized. This goal is achieved by a variational representation of quantum states based on artificial neural networks. I will then discuss applications in diverse domains, including prototypical open problems in Condensed Matter physics-- fermions and frustrated spins-- as well as applications to characterize and improve quantum hardware and software.
  [recorded movies]  


Nov. 5

Mike Zingale

Stony Brook University

Modeling Thermonuclear X-ray Bursts

X-ray bursts, brief flashes of X-rays seen in our galaxy, result from thermonuclear burning on the surface of neutron stars. These bursts repeat, and observations can help us understand the physics of dense matter in neutron stars. A wealth of observations shows that the burning begins in a localized region and spreads across the neutron star surface. There is a lot, however, that we do not understand, including the details of how the burning front spreads. Our group has been investigating X-ray bursts for a decade through multidimensional simulations. In this talk, I will describe some of the challenges in modeling X-ray bursts and the efforts our group has made to overcome them.
  [recorded movies]  


Nov. 12

Naoko Neilson

Drexel University

Neutrino Astronomy at the South Pole with IceCube

The Universe has been studied using light since the dawn of astronomy, when starlight captured the human eye. The IceCube Neutrino Observatory, located at the geographic South Pole, observes the Universe in a different and unique way: in high-energy neutrinos. IceCube's discovery in 2013 of a diffuse celestial neutrino radiation, in other words, isotropic high-energy neutrinos from beyond the solar system, started an era of neutrino astronomy. Last year, spectacular multiwavelength observations were made that indicate the first astronomical source to emit such astrophysical neutrinos being identified. I will motivate why neutrinos are a necessary messenger in high-energy astronomy, and review what these milestones mean. I will try to reconcile other IceCube analysis results to draw a coherent picture that is the state of neutrino astronomy.
  [recorded movies]  


Nov. 19

CANCELLED


TBA

TBA
   


Nov. 26

Mina Arvanitaki

Perimeter Institute

TBA

TBA
  [recorded movies]  


Dec 3

Allen Caldwell

MPI, Munich

TBA

TBA
  [recorded movies]  


Dec 10

Mike Wilking

Stony Brook University

TBA

TBA
  [recorded movies]  


 




Spring 2020 colloquia





 


 




 

Jan. 28

TBA

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  [recorded movies] 

MVFS

Feb. 4

TBA

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TBA

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  [recorded movies] 

MVFS

Feb. 11

TBA

TBA

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  [recorded movies] 

MVFS

Feb. 18

TBA

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  [recorded movies] 

MVFS

Feb. 25

TBA

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  [recorded movies] 

MVFS

Mar. 3

TBA

TBA

TBA

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  [recorded movies] 

MVFS

Mar. 10

Peter van Nieuwenhuizen

Stony Brook University

TBA

TBA

  [recorded movies] 

Essig

Mar. 24

Oliver Monti

University of Arizona

TBA

TBA

  [recorded movies] 

MVFS

Mar. 31

Marlan Scully

Texas A&M

TBA

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  [recorded movies] 

Liu

Apr. 7

TBA

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  [recorded movies] 

MVFS

Apr. 14

Pablo Jarrillo-Herrero

MIT

TBA

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  [recorded movies] 

MVFS

Apr. 21

Nora Berrah

University of Connecticut

TBA

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  [recorded movies] 

Weinacht

Apr. 28

TBA

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  [recorded movies] 

MVFS

May 5

Matthew Dawber

SBU

Graduate Program Awards

TBA

  [recorded movies]