NPAC (Nuclear/Particle/Astro/Cosmo) Forum

Host: 
Stefan Westerhoff
Speaker: Jeff Allen NYU

 

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Room and Building: 
4274 Chamberlin Hall

For over 30 years the Standard Model has served as our template for interpreting the world of particle physics. Recent results from neutrino experiments have shown that we must modify this long-standing theory. Current and future experiments will be discussed, with special attention on the KamLAND and Daya Bay neutrino oscillation experiments. The necessary changes for the Standard Model have consequences for the current set of fundamental particles, the nature of dark matter, and the matter-antimatter asymmetry of the universe.

Speaker: Dan Dwyer Caltech

 

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Room and Building: 
4274 Chamberlin Hall
Speaker: Alex Friedland LANL

 

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Room and Building: 
4274 Chamberlin Hall
The peculiar velocity of the intergalactic gas responsible for the cosmic 21cm background from the epoch of reionization and beyond introduces an anisotropy in the three-dimensional power spectrum of brightness temperature fluctuations. We review how measurement of this anisotropy by future 21cm surveys is a promising tool for separating cosmology from 21cm astrophysics. A more careful treatment of the effects of peculiar velocity than previously attempted is necessary, however, to fulfill this promise. In this talk, we set out to account for peculiar velocity in every detail, and clarify the roles of thermal vs. velocity broadening and finite optical depth.
We will also find whether nonlinear effect of peculiar velocity may spoil future 21cm measurements. The discussion in this talk, although in the context of the Epoch
of Reionization, may affect the interpretation of the 21cm intensity mapping in the post-reionization epoch.
Host: 
Peter Timbie and Vernon Barger
Speaker: Yi Mao UT Austin

 

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Room and Building: 
4274 Chamberlin Hall
The Pierre Auger Observatory is currently the world's largest cosmic ray
observatory. The southern site, in Malarguee, Mendoza, Argentia, covers
3000 km^2, instrumented with more than 1600 water Cherenkov detectors and
24 fluorescence telescopes.

I will present the status of the Pierre Auger Observatory and its recent
results. Even though the obesravtory was designed primarily as a detector
for charged cosmic rays, was clear from the beginning that it can also
identify photons and neutrinos. I will discuss the methods for the
identification of the primary cosmic rays, with emphasis on neutrino
tagging, and present the flux limits obtained.
Host: 
Teresa Montaruli
Speaker: Lukas Nellen UNAM

 

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Room and Building: 
4274 Chamberlin
Inflationary cosmology postulates that the Universe underwent a period of accelerated expansion in the first 10^-30 s after the Big Bang. Inflationary models are attractive because they solve outstanding problems in cosmology: the origin of structure, the absence of monopoles, and the horizon and flatness problems. Although inflation is consistent with existing data, the fundamental physics responsible for it is unknown. Cosmic Microwave Background (CMB) measurements promise to verify one of the predictions of inflation: odd-parity polarization modes (B modes).

CMB B modes have not yet been detected. The Q/U Imaging ExperimenT (QUIET) recently reported a measurement of the CMB polarization at 43-GHz (Q band). This is one of the best limits to date on inflationary B modes. Moreover the unique QUIET design leads to the lowest levels of systematic contamination in the inflationary signal reported by any CMB polarization experiment.

I will describe the QUIET instrument, how it mitigates systematic contamination, and results from the first season of Q-band observation. I will also report the status of analysis of the second-season 95-GHz (W-band) data.
Host: 
Peter Timbie
Speaker: Immanuel Buder University of Chicago

 

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Room and Building: 
4274 Chamberlin Hall
Host: 
Baha Balantekin
Speaker: Mark Caprio University of Notre Dame

 

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Room and Building: 
4274 Chamberlin
The anomalous dimuon charge asymmetry reported by the D0
Collaboration may be due to the tree-level exchange of some spin-0
particles that mediate CP violation in B_s-ar{B}_s meson mixing. In
this talk I will introduce the D0 result and show that the range of
couplings and masses necessary to generate a large charge asymmetry is
natural in a variation of the MSSM known as "uplifted supersymmetry".
Host: 
Andreas Ross
Speaker: Adam Martin Fermilab

 

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Room and Building: 
4274 Chamberlin
Host: 
Andreas Ross
Speaker: Ira Rothstein Carnegie Mellon University

 

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Room and Building: 
4274 Chamberlin Hall
Most often, the dark matter puzzle is analyzed along a single perspective, thus trying to answer a single question. Either "what is the dark matter?", focusing on its microscopic nature, or "how is dark matter distributed?" and "how does it cluster?" focusing on the large scale structure of the universe, or still "how does it
affect what we observe in the sky?", focusing on gravitational lensing. Both my scientific interests and some random fluctuations at the beginning of my career have conspired so that I would take on projects in all these fields. Leaving aside the ambition -- and the impossible task -- to be comprehensive, I will review some interesting aspects of these fields and some of my contributions.
Host: 
Peter Timbie
Speaker: Alberto Vallinoto Fermilab

 

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Room and Building: 
4274 Chamberlin Hall

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