Events at Physics |
Events During the Week of September 26th through October 3rd, 2021
Monday, September 27th, 2021
- Plasma Physics (Physics/ECE/NE 922) Seminar
- Toward prediction, avoidance, and mitigation of tokamak disruptions: research on MST and DIII-D
- Time: 12:00 pm - 12:55 pm
- Place: 2241 Chamberlin Hall
- Speaker: Brett Chapman , UW
- Plasma Theory Seminar
- Progress on Coupling CEL drift kinetics into NIMROD's Fluid Advance
- Time: 4:00 pm
- Place: 514 ERB or by Zoom
- Speaker: Joseph Jepson (UW)
- Abstract: Hybrid meeting format: 514 ERB or by Zoom Zoom Link Info: JOSEPH R JEPSON is inviting you to a scheduled Zoom meeting. Topic: JOSEPH R JEPSON's Personal Meeting Room Join Zoom Meeting Meeting ID: 635 987 7393 One tap mobile +13017158592,,6359877393# US (Washington DC) +13126266799,,6359877393# US (Chicago) Dial by your location +1 301 715 8592 US (Washington DC) +1 312 626 6799 US (Chicago) +1 929 205 6099 US (New York) +1 253 215 8782 US (Tacoma) +1 346 248 7799 US (Houston) +1 669 900 6833 US (San Jose) Meeting ID: 635 987 7393 Find your local number: Join by SIP 6359877393@zoomcrc.com Join by H.323 162.255.37.11 (US West) 162.255.36.11 (US East) 115.114.131.7 (India Mumbai) 115.114.115.7 (India Hyderabad) 213.19.144.110 (Amsterdam Netherlands) 213.244.140.110 (Germany) 103.122.166.55 (Australia Sydney) 103.122.167.55 (Australia Melbourne) 149.137.40.110 (Singapore) 64.211.144.160 (Brazil) 149.137.68.253 (Mexico) 69.174.57.160 (Canada Toronto) 65.39.152.160 (Canada Vancouver) 207.226.132.110 (Japan Tokyo) 149.137.24.110 (Japan Osaka) Meeting ID: 635 987 7393
Tuesday, September 28th, 2021
- Network in Neutrinos, Nuclear Astrophysics, and Symmetries (N3AS) Seminar
- Impact of EoS on Neutrino Opacities in Core-collapse Supernovae
- Time: 2:00 pm
- Place:
- Speaker: Zidu Lin , University of Tennessee Knoxville/ORNL
- Abstract: Neutrinos radiate 99% of the energy and play a crucial role in the explosion mechanism and nucleosynthesis of core-collapse supernovae. The neutrino interactions in hot and dense matter is a complex problem due to bound nuclei and the strong nuclear forces. In this work we calculate the dynamic and static response of the neutral current and charged current neutrino-nucleon interactions, from low-density region near the neutrino sphere to high-density region up to approximately 1.5 saturation densities at finite T, by applying random phase approximation (RPA). We emphasize on the consistency between an equation of state (EoS) and the neutrino opacity, by using the density-dependent residual interactions, effective mass, single nucleon potentials directly derived from an EoS which matches experiment, theory, and observation in various density regimes. We further analyze the effect of EoSs on neutrino opacities by calculating the statistical uncertainties of neutrino opacities. We found that our neutral current static response based on RPA is close to the results from model-independent virial approximation at low density, and our description of neutrino opacities at high densities have large uncertainties due to still unclear strong (especially spin-dependent) nuclear forces.
- Host: Baha Balantekin
- Theory Seminar (High Energy/Cosmology)
- SU(4) Flavorful Portal Matter
- Time: 4:00 pm - 5:00 pm
- Place: Chamberlin 5280
- Speaker: George Wojcik, University of Wisconsin-Madison
- Abstract: Dark Matter (DM) and its potential interactions with the Standard Model (SM) continue to present a rich framework for model building. In the case of thermal DM of a mass between a few MeV and a few GeV, a compelling and much-explored framework is that of a dark photon/vector portal, which posits a new U(1) ``dark photon" which only couples to the SM via small kinetic mixing (KM) with the SM hypercharge. This mixing can be mediated at the one-loop level by portal matter (PM) fields which are charged under both the dark U(1) and the SM gauge group. Models with appropriate portal matter content to produce finite and calculable kinetic mixing can arise from non-minimal dark sectors, in which the dark U(1) is a subgroup of a larger gauge symmetry under which SM particles might have non-trivial representations. In this talk, I will describe a model in which the dark U(1) is unified with another popular extension to the SM gauge group, a local SU(3) flavor symmetry. The full dark/flavor symmetry group is SU(4)×U(1), incorporating the local SU(3) flavor symmetry with PM appearing as a vector-like "fourth generation" to supplement the three generations of the SM. I then discuss the phenomenology of the new extended dark gauge group at experimentally accessible energies, including non-trivial consequences of the flavor symmetry being unified with the dark sector. Note: This is a hybrid event. A zoom link will be distributed via the seminar mailing list. To join, email the organizer.
- Host: Lars Aalsma
Wednesday, September 29th, 2021
- No events scheduled
Thursday, September 30th, 2021
- Astronomy Colloquium
- Reassessing Impact Bombardment in the Earth-Moon System
- Time: 3:30 pm - 5:00 pm
- Place: 4421 Sterling Hall, Coffee and Cookies 3:30 pm, Talk starts at 3:45 pm
- Speaker: Nicolle Zellner, Albion College
- Abstract: The characteristics of the impact flux in the Earth-Moon system, especially during the first 700 million to 1 billion years of Earth’s history, have been debated by scientists for decades. In particular, after analyses of lunar impact samples, uncertainties around its profile have persisted: did the impact flux taper off after final planetary accretion and sweep-up of debris or was there a short-lived influx of impactors at ~3.9 billion years ago? As Earth’s nearest neighbor, the Moon’s impact flux is applied to Earth, as well as to other planetary bodies in the inner solar system. Advances in acquiring, analyzing, and interpreting lunar (and other) data are allowing us to refine our interpretations of the nature and extent of the impact flux, from shortly after the solar system formed to the present. These data are allowing us to better understand how impacts may have influenced (or not) Earth’s biological and geological activities and permit us to also speculate on how it may have affected Mars.
- Host: Amy Barger
Friday, October 1st, 2021
- Graduate Introductory Seminar (Physics 701)
- Making Movies of Molecules - The Emerging Science of Powerful New X-ray Sources
- Time: 12:05 pm - 12:55 pm
- Place: 2241 Chamberlin
- Speaker: Uwe Bergmann, UW Madison Department of Physics
- Host: Sridhara Dasu
- Physics Department Colloquium
- Physical Review: An inside look
- Time: 3:30 pm - 4:30 pm
- Place: 2103 Chamberlin Hall
- Speaker: Victor Vakaryuk, APS (PRX)
- Abstract: Physical Review B is the largest dedicated journal in all of physics and the third largest in all of science. It receives around 10,000 submissions annually which are handled by a team of in-house and remote editors. Being one of them I will give an overview of the journal and its editorial policies and practices in a way that could be useful for the audience of both authors and referees who may or may not have experience with PRB. I will also spend some time talking about other members of the Physical Review family such as PRL, PRX and the recently launched open-access journal Physical Review Research.
- Host: Alex Levchenko