Jan. 28th: Seeing Color in Black and White: Recent QCD Measurements at the Tevatron Collider

Presentation by: Mike Strauss from the University of Oklahoma.

Abstract:
Quantum Chromodynamics (QCD) is the study of the strong force that binds quarks together inside neutrons and protons and, ultimately, holds the nucleus together. Each quark and gluon in the nucleus carries a color charge required of any object that interacts via the strong reaction. Yet, the colors of QCD are never observed directly due to color confinement, the fact that quarks are always bound tightly in groups, so that the properties of QCD must be understood by observing objects which have no color. This colloquium will discuss some of the recent measurements of the properties of perturbative QCD using the D0 detector at the Fermilab Tevatron Collider. These measurements give insight into the structure of the proton and have the potential of discovering physics not described by the standard model of elementary particles and fields. The results will include the most precise measurements of the inclusive jet cross section and dijet cross section taken at a hadron collider.

Post edited January 26, 2010 at 2:26 PM EST.

~ It only takes one bottle cap moving at 23,000 mph to ruin your whole day ~

Feb. 4th: The Large Hadron Collider and the Dawn of Discovery Decade

Presentation by: Yuri Gershtein from Rutgers University.

Abstract:
The Large Hadron Collider has finally produced first proton-proton collisions, signaling the beginning of a new era in experimental particle physics. The LHC energy covers the entire electroweak scale that, according to previous precision measurements and existing theoretical understanding, should contain physics beyond the standard model and shed light on electro-weak symmetry breaking. I will present some results from the pilot run of the LHC last year and discuss what future exploration might reveal.

Post edited January 26, 2010 at 2:27 PM EST.

~ It only takes one bottle cap moving at 23,000 mph to ruin your whole day ~

Feb. 11th: Spitzer Space Telescope Observations of Sulfur and Neon Abundances in Extragalactic H II Regions

Presentation by: Reginald Dufour from Rice University.

Abstract:
I will discuss the results of recent observations of the infrared spectra of H II regions in the spiral galaxies M33 & M83 and the irregular galaxy NGC 6822 made with the IRS on the Spitzer Space Telescope. These observations were the first measurements of the infrared emission lines of Ne+ and S+3 in the HII regions - enabling improved determinations of the abundances of the primary nucleosynthesis elements neon and sulphur in the ISM of three quite different systems. We analyzed our results, which also include measurements of Ne+2 and S+2, using photoionization models of H II regions with a variety of input stellar spectral energy distributions (SEDs) and discovered that the supergiant atmospheres of Pauldrach et al. track the ionization variations best. The resulting averaged Ne/S ratios determined for the ISM of the three galaxies were higher than the (controversial) solar value, as well as values predicted by stellar nucleosynthesis and galactic chemical evolution models. I then compare our results to other studies of Ne and S in Galactic and extragalactic H II regions and conclude with a discussion of potential future advancements in H II region abundance determination problems afforded by the upcoming infrared astronomy missions SOFIA and JWST.

~ It only takes one bottle cap moving at 23,000 mph to ruin your whole day ~

Feb 18th: Small Satellite Solutions to Problems in Near--Earth Space Science

Presentation by: Gregory Earle from the University of Texas at Dallas.

Abstract:
Interactions between the co-located "oceans" of ionized and neutral gas that surround the Earth create a host of interesting phenomena that have real-world consequences for satellite and terrestrial communication and navigation systems. These gaseous media and the physics governing their behavior have been studied over the last 50 years using a combination of rocket probes, satellites, radars, and computational modeling. These previous missions have been limited in scope due to the high cost of spaceflight; as a result our knowledge of the near-Earth space environment is based almost entirely on measurements that cannot adequately separate spatial and temporal causes and effects. Recent developments in the micro-satellite arena are beginning to change this by making it feasible to launch suites of satellites that make simultaneous measurements at many locations around the Earth. These developments are poised to revolutionize space science. In this talk the promise and challenges associated with these new microsatellite ventures are described and set in the context of the current "big problems" in space science. Universities have a significant part to play in these new state-of-the-art endeavors, with clear roles for students. Examples of ongoing research at the University of Texas at Dallas will be used to highlight a number of these areas, and will reveal some research avenues leading to rewarding career opportunities in aerospace industries. The recently launched C/NOFS satellite contains seven science instruments, including 2 from UT Dallas.

~ It only takes one bottle cap moving at 23,000 mph to ruin your whole day ~

Feb 25th: Long Range, Cold Rydberg Atom Molecules and Interactions

Presentation by: Jim Shaffer from the University of Oklahoma

Abstract:
Cold Rydberg gases are a promising system for exploring many of the ideas of quantum computation because of the dipole blockade effect. Dipole blockade takes place when the interaction between Rydberg stoms prevents additional Rydberg atom excitation due to the energy shift of the transition out of resonance with an applied laser field. A key to using dipole blockade is understanding Rydberg atom interactions. Aside from the dipole blockade effect, the interaction between Rydberg atoms (two excited Rydberg atoms) and a Rydberg atom and a ground state atom (one Rydberg atom and one ground state atom) can also bind the atoms in unique molecular states that have attracted much recent attention. In this talk we will focus on describing the Rydberg atom interactions that lead to blockade as well as experiments on molecular formation and collisions. Finally, we will briefly describe related experiments on hot Rydberg atom gases that have the potential to be used for the construction of quantum devices, such as memories and single photon sources, without laser cooling and trapping.

Post edited February 15, 2010 at 12:07 PM EST.

~ It only takes one bottle cap moving at 23,000 mph to ruin your whole day ~

Mar 4th: Spectroscopy of "Large" Molecules on Earth and Elsewhere

Presentation by: Jens Uwe Grabow from Hanover University

Abstract:
Larger molecules and molecular clusters are gaining not only technological but also academic attention with numerous questions on their structure and dynamical behaviour as well as fundamental problems in physics waiting to be answered. Targeted by high resolution spectroscopy, they impose a number of challenges, theoretically and experimentally. From the theoretical point of view, e.g., internal large amplitude motions result in complicated energy level schemes. For larger species exhibiting multiple internal motions at low barriers, the resulting spectra will be rather difficult to predict. From an experimental point of view, dense spectra at the presence of wide splitting patterns are difficult to assign. With narrow-banded techniques, even though very sensitive, identification of such spectral features becomes a paramount task. Nevertheless, the unrivalled resolution of these techniques provides a window to tackle fundamental questions in physics - potentially even beyond the standard model. Quantitative information on the structure, charge distribution, characterization of the chemical bond, details on internal dynamics, etc. - at the highest precision available to date - are encoded in pure rotational spectra obtained by microwave spectroscopy. Among others, we will present an example where internal movement is not governed sterically through space but electronically through a conjugated pi-bond system. Right now - about a quarter century after the introduction of supersonic-jet resonator Fourier-transform microwave spectroscopy - new exciting technical developments promise to overcome still existing limitations of rotational spectroscopy. First examples will be presented.

Post edited February 23, 2010 at 10:41 PM EST.

~ It only takes one bottle cap moving at 23,000 mph to ruin your whole day ~

Mar 11th:The Main Injector Particle Production Experiment (E907/P960) at Fermilab

Presentation by: Nick Solomey from Wichita State University

Abstract:
The MIPP experiment measures charged particle production in interactions of pions, kaons, protons, and their anti-particles at momenta ranging from 5 to 120 GeV/c on cryogenic and solid targets spanning the periodic table from hydrogen to uranium and on the composite NuMI neutrino production target. Particle tracks are measured with a TPC and 24 wire-chamber planes and particles are identified through TPC dE/dx, ToF, Ckov, and RICH detectors. The experiment performance, recent cross-section results from data taken in 2005 and 2006, and an upgrade future run plan will be presented. New results on charged Kaon mass from a unique method will also be covered.

Post edited March 3, 2010 at 2:11 PM EST.

~ It only takes one bottle cap moving at 23,000 mph to ruin your whole day ~

Mar 25th: Title N/A

Presentation by: Pat Lukens from Fermilab.

Abstract:
N/A

~ It only takes one bottle cap moving at 23,000 mph to ruin your whole day ~

Apr. 1st: Studies of Electron Attachment to Stable Molecules and Radicals, Ion-ion Neutralization, and Electron-catalyzed Reactions at Thermal Energies

Presentation by: Thomas Miller from Boston College and the Air Force Research Laboratory.

Abstract:
Electron attachment rate constants and products have been studied over a temperature range from 300 to as high as 1100 K in a flowing-afterglow Langmuir-probe (FALP) apparatus originally constructed at the University of Oklahoma. This work has resulted in new information on even the most-studied molecule of all, SF6, as well as for related molecules such as SF5C6H5, and sulfur oxyhalides, transition-metal fluorides and trifluorophosphines, freons, Cl2, SO3, O3, NF3, PF5, ClONO2, and many organic compounds. Experiments have just been completed on electron attachment to chlorine azide (ClN3), which is a reactant in the AGIL laser (all-gas iodine laser) and is the starting point for generating what is thought to be cyclic-N3. The FALP method has also been used to study negative ion mutual neutralization with Ar+. Our initial publication on ion-ion neutralization noted the presence of "unexpected" negative ions in the mass spectra at high electron densities, such as SF4- from work with SF6 and PSCl- from work with PSCl3. We have now identified the source of these unexpected ions as due to electron attachment to radicals produced in the initial attachment reaction and in ion-ion neutralization, and are able to deduce rate constants for the secondary attachment and for ion-ion neutralization. At high electron densities (>10^10 cm-3) we observe what appears to be electrons acting as a third body in enhancing negative ion neutralization with Ar+. While ternary reactions with neutral third bodies are well known, the electron-catalyzed reaction presents an interesting new theoretical problem.

~ It only takes one bottle cap moving at 23,000 mph to ruin your whole day ~

Apr 15th: The Puzzle of Charge and Mass

Presentation by: Stuart Raby from Ohio State University

Abstract:
Beginning with the seminal work of Rutherford, Geiger, and Marsden in 1911, physicists have investigated the atom using particle beams (alpha particles, and protons) as probes. They developed new detection methods: the geiger counter, scintillators, cloud and then bubble chambers. This new paradigm for probing matter and new detectors led to many discoveries. To make a long story short, by 1974 the chaos of discovery lead to the Standard Model describing all observed particle phenomena in terms of three fundamental forces (4 including gravity) and the fundamental building blocks of matter, quarks, and leptons. Only now, after the dust of this chaotic discovery settles, are we able with hindsight to recognize the underlying principles which define the theory we call the Standard Model. It is these principles and their logical extension which I will attempt to describe in this talk.

~ It only takes one bottle cap moving at 23,000 mph to ruin your whole day ~

Apr 29th: Seeing Color in Black and White: Recent QCD Measurements at the Tevatron Collider

Presentation by: Mike Strauss from the University of Oklahoma.

Abstract:
Quantum Chromodynamics (QCD) is the study of the strong force that binds quarks together inside neutrons and protons and, ultimately, holds the nucleus together. Each quark and gluon in the nucleus carries a color charge required of any object that interacts via the strong reaction. Yet, the colors of QCD are never observed directly due to color confinement, the fact that quarks are always bound tightly in groups, so that the properties of QCD must be understood by observing objects which have no color. This colloquium will discuss some of the recent measurements of the properties of perturbative QCD using the D0 detector at the Fermilab Tevatron Collider. These measurements give insight into the structure of the proton and have the potential of discovering physics not described by the standard model of elementary particles and fields. The results will include the most precise measurements of the inclusive jet cross section and dijet cross section taken at a hadron collider.

Note: this is the new date for Dr. Strauss' talk due to the snow day on Jan. 28th

~ It only takes one bottle cap moving at 23,000 mph to ruin your whole day ~

May 6th: The Standard Model of Cosmology and Open Questions

Presentation by: Bharat Ratra from Kansas State University.

Abstract:
N/A

~ It only takes one bottle cap moving at 23,000 mph to ruin your whole day ~