Particle Physics for the Future in the U.S.

As a U.S. experimental particle physicist, I helped discover the Higgs boson with the CMS collaboration, and we still have much to learn about what we found as well as what else could be out there waiting to be found. Particle physics is a rich field of study that searches for the smallest components of the universe and how they interact with each other. Questions include how the cosmos is expanding and what we can tell about the beginning of the universe and how it got to be the way it is. Theorists and experimentalists have been, and continue to be, very busy trying to provide a framework and describe what the universe is. Tools of study include accelerators that collide particles together at high energies (the energy frontier), accelerators that can produce a high intensity of particles to study rare processes (the intensity frontier), and detectors that look for particles from space (the cosmic frontier).

In the U.S. we have been fortunate to have funding from the Department of Energy (DOE) and the National Science Foundation (NSF) to pursue this research, and the U.S. physicists are still recognized as world leaders in this field. Around a quarter of the physicists in the CMS collaboration are funded by the U.S., and significant detector and accelerator contributions to CMS and the LHC came from U.S. funding. The larger DOE contribution to particle physics is now at about $750 million a year, but it has been reduced by about 25 percent from 10 years ago, as each year there is less and less. This is significant funding from the taxpayer for fundamental research that we are quite thankful for. However, the continued decrease in funding has led to some hard choices, and the U.S. may not enjoy a global leadership position in this field much longer.

The particle physics community realizes that substantial planning needs to take place to ensure that the best physics is done with the investment of the government. The Division of Particles and Fields in the American Physical Society started a community planning exercise in 2013 to help plan the next 10 years of particle physics investments in light of the Higgs discovery, new information about neutrinos, and new information about dark energy and the accelerating universe. The DOE/NSF then received a report last week from the Particle Physics Project Prioritization Panel (P5), which followed up on the community planning exercise. The P5 panel was given target budgets to meet and told to prioritize the potential contributions. The five science drivers in the report are:

  • Use the Higgs boson as a new tool for discovery.

  • Pursue the physics associated with neutrino mass.
  • Identify the new physics of dark matter.
  • Understand cosmic acceleration (dark energy and inflation).
  • Explore the unknown (new particles, interactions, and physical principles).
  • To enable these drivers, hard choices were made, and recommendations for funding have been given to DOE and NSF. The lowest budget scenario was considered "precarious," where "[i]t is close to the point beyond which the US would ... lose its position as a global leader in this field...."

    I encourage you to find out more about the exciting science to be done. I hope that after this significant planning exercise, our field will be able to make the case that we are good stewards of the public money, have an exciting program that benefits humanity, and will receive more positive news from the budgets to come.