Young-Kee Kim in the Library for Symmetry

Young-Kee Kim: Research

As an experimental scientist, I do research on particle physics to understand how the universe works at the most fundamental level by discovering and understanding the fundamental constituents (elementary particles) and the forces acting among them and on accelerator physics to design and build much more powerful accelerators for future particle physics and other sciences.

If you are interested in joining my group, please contact me.

Current Activities: ATLAS at LHC and Accelerator Physics (since 2009)

2012 was was a watershed for particle physics. The decadeslong quest to discover the Higgs boson, the last puzzle piece in the current theory of particle physics (the standard model), is essentially complete. But this theory does not explain some fundamental aspects of our Universe. From the neutrino's very small mass to our matter-dominant universe, dark matter and dark energy, we know there is more going on. My research addresses some of these unanswered questions by searching for new physics at the Large Hadron proton-proton Collider (LHC) at CERN, currently the highest-energy accelerator in the world. After a two-year upgrade, LHC resumed its operation at 13 TeV late 2015 -- roughly twice that at which the Higgs was discovered. Any new particles or new physics found at LHC will ervolutionalize our view of physics.

Using the ATLAS detector at LHC, my group focuses on (i) a deeper understanding of the nature of the Higgs, (ii) searches for new physics using the Higgs as a new tool (e.g. decay of Higgs into dark matter particles), and (iii) searches for a new messenger particle that couples to both dark matter an quarks. Achieving these goals requires significant improvements of detectors and triggers. My group has been working on the new tracking trigger (FTK) that has more capability and flexibility than the current trigger system.

In addition, my group is exploiting novel concepts in accelerator science and technology, studying limitations affecting the acceleration and intensity of particle beams at a fundamental level, and developing new approaches to overcome these limitations. Read more here.

Past Activities: CDF at Tevatron (1990 - 2013)

Until 2009, the Tevatron proton-antiproton collider was the world's highest energy accelerator and the top quark, the most massive elementary particle, was discovered in 1995 by the CDF and DZero experiments at the Tevatron. Using the CDF detector at the Tevatron, my group measured the masses of the W boson and the top quark very precisely (numerous measurements were made using different decade modes, different datasets and different analysis techniques). These measurements predicted the mass of the Higgs boson to be less than 145 GeV. The mass of the Higgs boson (discovered in 2012) turned out to be 125 GeV! My group has also involved other topics measuring the diboson production process whose final states are similar to those of the Higgs boson process (this is an important step for designing Higgs searches), the Bs oscillation, the lifetime of the top quark (by measuring its width), the mass difference between the top and anti-top quarks, properties of the Z and W boson (their production cross section and forward-backward asymmetry), and decay rates of bottom and charm mesons.