The sad state of US particle physics

The Economist summarizes the sorry state of hep-ex in the US. Even in the optimistic scenario, in which the ILC is sited here, America will be a backwater for particle experiment for a decade to come. Does anyone other than a few particle physicists care? The NRC panel had to recruit economist and former Princeton president Harold Shapiro to lend gravitas to the report. What does Shapiro know about fundamental science or technology? What does this say about the prestige of physics today relative to its glory days 50 years ago?

A report on the state of fundamental physics in America

NEAR Waxahachie in Texas, there is a hole in the ground. Not just any old hole. This one is almost 23km long and curves in what would be, if it were extended, a circular loop. It is the site of what was intended to be the world's biggest and best particle accelerator, a machine capable of unlocking some of the fundamental secrets of nature itself. Ever since the project to build it was cancelled in 1993, after nearly $2 billion had been spent on construction, America's lead in particle physics has been shrinking. This week, a report by the country's National Research Council (NRC) outlined what America can do to regain its pre-eminence.

The outlook is grim. After decades of making discoveries about the fundamental building blocks of nature, America's particle-physics colliders are to close. The Tevatron at Fermilab, near Chicago, is the world's highest-energy particle-smasher. But that honour will be wrenched from it next year, when the Large Hadron Collider (LHC) opens for business at CERN, the European particle-physics laboratory near Geneva. The Tevatron is scheduled to shut by the end of the decade, and the LHC is expected to dominate international particle physics for the next 15 years.

America's other accelerators are in trouble, too. Work at the Stanford Linear Accelerator Centre is moving away from particle physics and into generating high-energy X-rays. Funding for the Relativistic Heavy Ion Collider at the Brookhaven National Laboratory is so tight that the machine managed to keep running only after a philanthropist intervened. Many American particle physicists have switched their attentions to the LHC. And while physicists dream of shiny new machines, none is scheduled to be built in America. In the review of its top ten research advances of 2005, Science singled out American particle physics for the booby prize.

This is a shame. While particle physics does not produce economic returns in the lifetimes of the administrations that fund the experiments, it is a fascinating endeavour. Over the past 100 years, physicists have succeeded in identifying the fundamental building blocks of the universe, both in terms of matter and of the forces that act on it. Yet the so-called Standard Model of particle physics, which weaves these discoveries together, and which has proved so successful to date, is incomplete. If physicists are to improve on it, they need machines that supply particles at higher energies to probe the nature of space and time. Such machines could provide answers about how the universe began and how it will evolve.

In this light, the NRC report makes interesting if somewhat biased reading. It wants America to retake the lead in particle physics, and to host the next new particle accelerator to be built after the LHC. A decision on whether to build this machine, dubbed the International Linear Collider, will not be taken until the initial results from the LHC are known. If these point to more fundamental physics beyond the Standard Model, as is widely expected, then there would be mileage in building a more powerful accelerator to study these phenomena. Such a decision would not be made until 2010, but America's physicists are keen for their country to host such a facility.

To do so, the NRC reckons, America will need to spend between 2% and 3% more each year in real terms on particle physics. That might not sound onerous, but it amounts to $500m over the next five years.

European particle physicists are also keen to lead the world. A similar panel of experts is close to finalising a European strategy. The CERN Council Strategy Group, as it is called, will meet near Berlin next week to hammer out a consensus. Then, in July, this consensus will be presented to the politicians who decide the funding of particle physics.

At present, Europe is poised to take the lead: it will soon have the world's biggest and best particle accelerator. Whether CERN could afford to host the International Linear Collider, though, is a moot point. The laboratory has had to take out loans to build the LHC, and it is likely that any future money would be spent on upgrading that machine.

Then there is Japan, which has a promising programme in neutrino physics, another area where the report urges America to push forwards. Japan recently lost the fight to host the International Thermonuclear Experimental Reactor, an expensive international project which aims to demonstrate that nuclear fusion could produce power on a commercial basis, so it feels it is owed something. And, depending on the strengths of their economies when the time comes to make the decision, Russia, China and India could all be interested, too.

In any event, American particle physics looks set for a period in the wilderness. Whether the country can recapture its superiority after such a spell depends on whether there is the political will to pour more money into holes in the ground.