Chris Quigg

Theoretical Physics Department · MS106
Fermi National Accelerator Laboratory
P.O. Box 500 (Kirk Road and Pine Street)
Batavia, Illinois 60510 USA
phone: +1 (630) 840-3578 · fax: +1 (630) 840-5435 · email: quigg@fnal.gov

The second edition of Gauge Theories of the Strong, Weak, and Electromagnetic Interactions, published by Princeton University Press, is now available. See the Illustration Package (digital versions of the figures) for classroom use.


March 2014 update to the top-mass time series originally published as Figure 1 of "Top–ology," Phys. Today 50N5, 20 (1997) [extended version at hep-ph/9704332].


Project X Physics Book


"American particle physics at CERN and at home," Physics Today Online, May 31, 2013


"The World According to Higgs," Fermilab Auditorium Lecture Series: streaming video


ICTP South American Institute for Fundamental Research School, Particle Physics in the LHC Era, April 2013: "The Standard Model—Its Magic and Its Shortcomings" (five lectures)


Fermilab Colloquium, April 4, 2012: "The Higgs Boson for the Masses?" and Video


"The Boundless Horizons of Supercollider Physics," slides from my Sakurai Prize Lecture at the April 2011 APS Meeting


EHLQ preprint or Reviews of Modern Physics


Resource Letter: Quantum Chromodynamics on arXiv or in American Journal of Physics (November 2010)


Download "Unanswered Questions in the Electroweak Theory" reprint from Annual Reviews (2009)


Minute Particulars & Hidden Symmetries Symposium at Fermilab, December 14 – 15, 2009


American Association of Physics Teachers established the John David Jackson Excellence in Graduate Education Award


Parton Luminosity Plots for the LHC: here and here


The LHC at CERN is shut down for upgrades  · ATLAS Tour · 2007 update · CMS Tour · 2007 update · Tracker


 


Particle Physics!

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. We are experiencing a remarkable flowering of experimental particle physics and of theoretical physics that engages with experiment!

The Large Hadron Collider at CERN is advancing 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 is the discovery of a 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 of exquisite sensitivity, in which new physics may manifest itself through quantum corrections, provide an essential complement to the LHC research program and give us a virtual look at even higher energy scales. Many initiatives promise to develop our understanding of the problem of identity: what makes a neutrino a neutrino and a top quark a top quark. Here I have in mind the work of the e+e- flavor factories and the LHC on CP violation and the weak interactions of the b and c quarks; wonderfully sensitive experiments on CP violation and ultrarare decays of kaons; the prospect of definitive experiments on neutrino oscillations and the nature of the neutrinos; and a host of new acclerator-based experiments to search for nonconservation of lepton number or baryon number.

Experiments that use natural sources also hold great promise for the decades 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, a Higgs factory, a TeV-scale linear electron-positron collider or muon collider, and a very-high-energy hadron collider.



Current Research

 
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. Much of my current work is linked with the experimental program of the Large Hadron Collider, with special attention to the problem of electroweak symmetry breaking. I maintain an active interest in quarkonium spectroscopy and the new mesons associated with quarkonium.