Physics
Office Hours: Fermilab Office nearly always, and I'm easy to find by email.
Research Interests:
Experimental quantum chromodynamics at CMS. That means jets physics, where jets are the sprays of particles which result from quarks and gluons smacking each other free of the protons which went into the collision. Just measuring the spectrum of jet momenta transverse to the beam pipe will be nontrivial, since the energy deposited in the calorimeter cannot all be collected, and software must be made to decide which energy deposits should be considered as parts of which jets. I'm interested in measuring the ratio of the numbers of two-jet events ("dijets") of two kinds: Central (both partons scattered at a hard right angle) and slightly forward (both partons scattered slightly more or slightly less, but not a real right angle. QCD predictions are for a ratio near 0.5, since QCD interactions prefer to be "forward." It doesn't matter very much how much energy is in the two jets. BUT: Most models where quarks secretly are made of smaller particles have very high values of this ratio, even well below the energies corresponding to such tiny sizes. Likewise we can examine the distributions and correlations of angles between jets; reconstructed di- and tri-jet (and so on) masses; the transverse momentum distributions of events with specific jet topologies (cases when certain types of gluon and quark interactions probably happened); and the distribution of energy with jets. All such measurements can be predicted by and compared to QCD calculations using Monte Carlo methods. If there's ever time, maybe something a little more fun: Measurement of anomalous trilinear gauge couplings (the non-Abelian structure of the electroweak vector gauge bosons). These could be measured in diboson LHC events where one W boson decays leptonically (easier to sift out), and the other decays to two jets (higher cross section). It will be important to beat down QCD jets faking the hadron W boson decay (so that's exciting to learn about for me). The quartic couplings are also on my mind, but trickier to measure. What about Z -> ZW+W- or W -> WZZ which will require an understanding of jet multiplicity in QCD, and being able to pay the price of smaller coupling constants, nastier phase space, and possibly some helicity price as well. Maybe helicity will help, actually. If there is an energy frontier resonance (read: "a new subatomic particle") which is responsible for electroweak symmetry breaking, this analysis will be very sensitive to it (I'm looking at you, Higgs).Education:
BA, Physics, Harvard 2001 Jets all the way