Events at Physics
Events on Thursday, February 22nd, 2018
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- Where is all the antimatter?
- Time: 3:30 pm
- Place: 4274 Chamberlin Hall
- Speaker: Nuno Barros, University of Pennsylvania
- Abstract: Everything we know about the microscopic world tells us that the universe should be composed of equal parts matter and antimatter. All known particle interactions and decays always produce equal amount of each.
Yet all the known, observable, universe is composed solely of matter, suggesting that a small surplus of matter might have taken form shortly after the Big Bang.
A possible explanation for this asymmetry may be that neutrinos, unlike all other fundamental particles of Nature, may have behavior that distinguishes matter and antimatter. Ironically, the property that allows this is that neutrinos
and antineutrinos may be the same thing. Many experiments worldwide that are running or under construction, are investigating this possibility.
This talk will discuss this problem and the different approaches to address it in both present and upcoming neutrino
experiments, with particular emphasis on long baseline neutrino oscillations with DUNE and neutrinoless double beta decay with SNO+. The physics goals and expectations of these experiments will also be discussed.
- Host: Sridhara Dasu
- Astronomy Colloquium
- The Positive Side of the Galactic Baryon Ledger: the Evidence for Cold Inflow
- Time: 3:30 pm
- Place: 4421 Sterling Hall, Cookies and coffee 3:30 pm , Talk starts at 3:45 pm
- Speaker: Chris Howk, University of Notre Dame
- Abstract: The flow of gas through galactic halos is crucial to the evolution of galaxies, as the nature of such flows can dictate the star formation properties of galaxies and regulate their metallicity. Outflows through the circumgalactic medium (CGM) carry metals away from galaxies (although many may return), while infalling metal-poor gas from the intergalactic medium dilutes the metals in galaxies and provides new fuel for star formation. The nature of the infalling baryons, in particular, is of great interest, but such gas has historically been difficult to identify. I'll review our work on galaxies both near and far that suggests the inflow of new matter is robust even in today's massive galaxies.