VU Physics and Astronomy Colloquium

Monday, Feb. 21, at 4:00 PM in NSC 224. Join us for refreshments in NSC 231 at 3:45 PM.

NOTE: Special date and time

 

"Discovery Physics With Jets at the Large Hadron Collider"

Dr. Adam Gibson, University of Toronto

What are the fundamental constituents of matter?  Is anything truly uncuttable?  It's one of the oldest questions in science.  Rutherford showed us the atomic nucleus, and for forty years we have known that protons and neutrons have substructure as well: quarks and gluons.  Are quarks fundamental?  Or might they too have substructure?  (Is it turtles all the way down?)  At CERN's Large Hadron Collider we are now addressing questions like this one with the highest energy particle collisions ever attained in the laboratory.

After years of preparation, CERN's Large Hadron Collider (LHC) enjoyed a successful first year of proton-proton operations in 2010.  Commissioning of the detector with cosmic rays has quickly transformed into physics analysis and publications with collision data.  Abundantly produced at colliders, samples of jets from quark and gluon production were used for several of the first ATLAS physics publications.  These included measurements confirming predicted properties of jet production, but also searches for new physics using events  featuring two highly energetic jets and the first search at the LHC to exceed the reach of the Tevatron.  With no evidence for new physics, we  proceeded to set limits on various postulated phenomena including quark substructure and quantum black hole production in the presence of large extra dimensions.  After a description of the LHC and the ATLAS detector, I will describe our searches for new physics using dijet events.  And, I will present our brand new search results with the full 2010 dataset.