Scientists at universities across the country are lobbying to have their state be the site of the world's largest particle accelerator, a federally funded $6 billion device that could lead to breakthroughs in high energy particle physics.

President Reagan approved using federal money for the project three weeks ago. Scientists are confident that Congress will also approve funding the collider, and they want to see their universities and states benefit from the prestige and economic gains that will accompany the device.

The accelerator, known as the Superconducting Super Collider (SSC) "would be the most prestigious science lab in the country," said Dr. Barry C. Barrish, a physics professor at the California Institute of Technology.

With an underground circumference of 52 miles, the SSC will be 13 times larger than the world's largest existing collider, the Fermi Laboratory in Chicago.

SSC is "the dream machine of particle physics," said harvard's Sheldon L. Glashow, Higgins Professor of Physics. The accelerator will operate at a higher energy than that of any collider now in existence, and will therefore be able to help scientists learn more about the fundamental structure of matter, Barrish said.

The accelerator would also provide approximately 2500 new jobs for the area in which it is located, said Dr. Eugene C. Loh, a physics professor at the University of Utah.

At last count, about 25 states, including Utah, Michigan, California, Ohio, Texas, and New York were competing to house the acceleration.

If Congress, as expected, approves federal funding of the project, contending states will submit site proposals to a special panel composed of representatives of the National Academy of Science and the National Academy of Engineering, Barrish said.

The panel next year will pick five potential sites it thinks suitable for the project. Later in 1988, the Department of Energy will make the final decision on where the SSC will be built.

The choice "will obviously involve a certain amount of politics," said Lawrence W. Jones, physics department chairman at the University of Michigan.

Every state proposal has a university behind it, he said. "It's the scientists at the universities who are most cognizant of what's going on," Jones added.

Massachusetts does not appear to be among the contenders at this time, according to Harvard's Glashow, a Nobel Prize laureate in physics. He said the lack of response in New England is "very curious because there are certainly places where you could do it."

"Requests to the government offices have indicated that [Massachusetts] is interested in energy conservation, not energy physics," Glashow said.

Harvard physicists have not been attempting to propose accelerator sites "because it's assessed that the political likelihood [of success] is small enough that it's better to do research" than to work on proposals, said Paul C. Martin, dean of the Division of Applied Sciences.