The location of today’s announcement, at the Institute for High Energy Physics in Beijing, underscores the growing role and ambition of Asia, particularly Japan and China, to become major players in high-energy physics, a field that has been dominated by the United States and Europe in the last century.

Image The International Linear Collider will use 16,000 superconducting cavities to accelerate electrons and positrons to extremely high energies. Credit... International Committee for Future Accelerators

In its initial phase the collider would be 31 kilometers (20 miles) long and hurl electrons and their antimatter opposites, positrons, together with energies of 500 billion electron volts. Later the collider could be extended to 50 kilometers (31 miles) and a trillion electron volts.

The proposed machine, physicists say, is needed to complement to the Large Hadron Collider now under construction at the European Center for Nuclear Research, CERN, outside Geneva. That machine will be the world’s most powerful when it goes into operation this fall, eventually colliding beams of protons with 7 trillion electron volts of energy apiece. Physicists hope that using it they will detect a long-sought particle known as the Higgs boson, which is thought to endow all the other constituents of nature with mass. They hope, too, to discover new laws and forms of matter and even perhaps new dimensions of spacetime.

But protons are bags of smaller particles called quarks and gluons, and their collisions tend to be messy and wasteful. Because electrons and positrons have no innards, their collisions are cleaner, so they can be used to create and study with precision whatever new particles are found at Cern.

The hitch is that until the hadron collider proves its worth by actually finding something new, the governments of the world are unlikely to sign on to contribute a share of the billions.