Chris Quigg

Very soon, the Large Hadron Collider at CERN will advance the experimental frontier of particle physics to the heart of the Fermi scale, reaching energies around one trillion electron volts for collisions among the basic constituents of matter. We do not know what the new wave of exploration will find, but the discoveries we make and the new puzzles we encounter are certain to change the face of particle physics and echo through neighboring sciences.

In this new world, we confidently expect to learn what distinguishes electromagnetism from the weak interactions, with profound implications for our conception of the everyday world. We will gain a new understanding of simple and profound questions: Why are there atoms? Why chemistry? What makes stable structures possible? A pivotal step will be the search for the Higgs boson and the elaboration of its properties. But there may be much more: we have hints of other new phenomena, including some that may clarify why gravity is so much weaker than the other fundamental forces. We also have reason to believe that candidates for the dark matter of the Universe could be lurking on the Fermi scale.

Beyond the Fermi scale lies the prospect of other new insights: into the different forms of matter, the unity of quarks and leptons, and the nature of spacetime. The questions in play all seem linked to one another—and to the relationship of the weak and electromagnetic interactions. Exploring the Fermi scale will help us to define the questions more acutely, and may set us on the road to answering them.

Experiments that use natural sources also hold great promise for the decade ahead. We suspect that the detection of proton decay is only a few orders of magnitude away in sensitivity. Astronomical observations should help to tell us what kinds of matter and energy make up the universe. The areas already under development—if not exploitation—include gravity wave detectors, neutrino telescopes, cosmic microwave background measurements, cosmic-ray observatories, γ-ray astronomy, and large-scale optical surveys. Indeed, the whole complex of experiments and observations that we call astro/cosmo/particle physics should enjoy a golden age.

If we are inventive enough, we may be able to follow this rich menu with the physics opportunities offered by a (muon storage ring) neutrino factory and a linear electron-positron collider or muon collider. I expect a remarkable flowering of experimental particle physics, and of theoretical physics that engages with experiment.

Our theories of the fundamental particles and the interactions among them are in a very provocative state. We have achieved a simple and coherent understanding of an unprecedented range of natural phenomena, but our new understanding raises captivating new questions. In search of answers, we have made far-reaching speculations about the universe that may lead to revolutionary changes in our perception of the physical world, and our place in it. See my colloquium, "The Coming Revolutions in Particle Physics."

 
My work ranges over many topics in particle physics, from electroweak symmetry breaking and supercollider physics to heavy quarks and the strong interaction among them to ultrahigh-energy neutrino interactions. The essential interplay between theory and experiment is a guiding theme. Because we cannot hope to advance without new instruments, I have devoted much energy to helping to define the future of particle physics—and the new accelerators that will take us there.

My current work emphasizes the problem of electroweak symmetry breaking, with an eye to the forthcoming experimental program of the Large Hadron Collider. With Robert Shrock, I studied Gedanken worlds without Higgs fields, to illuminate how different the world would have been in the absence of a specific mechanism arranged to hide the electroweak symmetry. My status report on unanswered questions in the electroweak theory has just been published in the Annual Review of Nuclear and Particle Science. In preparation for initial LHC running below the design energy of 14 TeV, I prepared a note on the utility of parton luminosities for assessing the LHC physics potential as a function of collision energy.