Particle Physics Panel: US Needs More Global Partnership

By Michael Lucibella

A new top-level government report urges the United States to become more of an international player in the field of high-energy physics.

The Particle Physics Project Prioritization Panel, referred to as P5, submitted its draft outline for the next decade of science experiments funded by the National Science Foundation and the Department of Energy’s (DOE) Office of Science on May 22, recommending programs to boost, continue or cut.

“It’s more than a collection of cool experiments,” said Andrew Lankford, chair of the DOE Office of Science’s High Energy Physics Advisory Panel (HEPAP). “It’s a ten year strategic plan that’s been put forward.”

One of the report’s top recommendations is that the United States internationalize its biggest planned physics experiment, the Long Baseline Neutrino Experiment.

“The activity should be reformulated under the auspices of a new international collaboration, as an internationally coordinated and internationally funded program, with Fermilab as host,” the report reads. “The experiment should be designed, constructed, and operated by the international collaboration.”

The project, to be renamed the Long Baseline Neutrino Facility, looks for neutrino oscillations by shooting a stream of neutrinos 800 miles through Earth from Fermilab to a giant detector buried almost a mile underground in South Dakota. Projected budget shortfalls have dogged the project, putting the underground detector in jeopardy.

The report also recommends international investment in the upcoming high-luminosity upgrade for the Large Hadron Collider and some level of support for Japan’s International Linear Collider, depending on available budgets.

“Particle physics is global,” said Steven Ritz of the University of California, Santa Cruz and chair of P5. “The United States and major players in other regions can together address the full breadth of the field’s most urgent scientific questions if each hosts a unique world-class facility at home and partners in high-priority facilities hosted elsewhere.”

Although for international consortia large projects are best, the report’s authors envision a leading role for the United States in a number of small and medium sized projects. It recommends increasing efforts to develop a range of second-generation dark matter detectors, the Large Synoptic Survey Telescope, and Cosmic Microwave Background experiments.

“Several medium and small projects in areas especially promising for near-term discoveries and in which the US is, or can be, in a leadership position, will move forward under all budget scenarios,” the report said.

To help develop this capacity, the panel also urged investing more in building new experiments, by upping the fraction of the DOE Office of Science’s construction budget from 16 percent to between 20 and 25 percent.

However a number of other projects were targeted for termination. These included NuSTORM, RADAR, CHIPS and LAr1 neutrino detectors, the MICE and MAP muon experiments and the ORKA kaon experiment. In addition, the report recommended that development of the Dark Energy Spectroscopic Instrument move forward provided that the overall budget increases by at least 3 percent per year.

The House Science, Space and Technology subcommittee on energy seemed positive about the panel’s recommendations when they were presented at a June 10 hearing. Members of congress appeared receptive to the report’s recommendations and the partisanship that has worked its way into other committee meetings was largely absent.

“While the US remains in a state of fiscal uncertainty, reducing overall federal spending in order to arrive at a balanced budget should be a top priority. Yet during this process, we cannot overlook the fact that the federal government plays a critical role when it comes to the nation’s long-term competitiveness in the physical sciences,” said subcommittee chair Cynthia Lummis (R-Wyo.).

The P5 largely built their recommendations off the lengthy Community Summer Study 2013, popularly known as “Snowmass on the Mississippi.” The nine-day-long seminar brought together hundreds of physicists from a range of disciplines within high-energy physics to weigh in on the future of tie field. They produced a comprehensive report of several thousand pages that highlighted outstanding research questions, recommended directions for research and possible future experiments.

The P5, appointed by HEPAP and last convened in 2008, has been reviewing the Snowmass report and assembling their recommendations for the DOE’s Office of Science since September.

DOE charged the panel to come up with recommendations for the next ten years under different budget scenarios: flat for three years, then 2 percent growth over seven years; two percent growth for the first three years followed by seven years of 3 percent growth, and an “unconstrained budget” which essentially asked the panel to come up with a program for the U.S. to lead the world in high energy physics.

For more information on the P5 meeting, visit DOE's HEPAP Charges/Reports page.