NBIA Colloquium – Niels Bohr Institute - University of Copenhagen

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NBIA Colloquium

 Speaker: Lance Dixon (Stanford)

Title: Twistor Spinoffs for Collider Physics

Abstract:  Over the next decade, the search for the Higgs boson and for new phenomena at short distances will be carried out by colliding protons at the Large Hadron Collider at CERN. Each proton is a complicated bound state of quarks and gluons. Feynman once described proton collisions as "smashing two Swiss watches together to figure out how they work." In recent decades, we have learned muchbetter how the Swiss watches work, using the theory of quark-gluon interactions, quantum chromodynamics. We can predict the results of collisions at the LHC within the Standard Model, and see whether the predictions hold up, or whether new particles are required by the data. But a major bottleneck is simply in adding up Feynman diagrams. The rules are well known, yet thousands of extremely complicated diagrams have to be evaluated. The sum of all diagrams is often much simpler than the typical diagram, suggesting hidden symmetriesand better ways to compute. Over the past three years, spinoffs from  "twistor string theory", related to the general analytic properties of quantum-mechanical amplitudes, have led to very efficient alternatives to Feynman diagrams, which promise to help improve our ability to find new physics at the LHC.

Refreshments after the lecture!