For a decade, from 1969 to 1979, the strategic arms control process acronymed SALT was a centerpiece of American diplomacy, then it disappeared from the diplomatic scene. For two days here last week, a group of 14 experts and observers tried to figure out what had happened to it, and whether it will soon be revived.

The meeting at the Lyndon B. Johnson School of Public Affairs had the flavor of a Christmas tree lighting ceremony. These particular lights have been turned off since the SALT II treaty died after the Soviet army invaded Afghanistan in December, 1979. Turning them on again made the eyes blink.

The conference here demonstrated that American arms control specialists have gotten used to the fact that the national consensus that made 10 years of SALT possible has collapsed, leaving the country deeply divided about the purposes of nuclear weapons and the best ways to limit the unprecedented dangers these weapons pose.

The wreckage of that consensus has left an odd division of opinion about the future prospects for formal agreements to limit nuclear arms. Representatives here of the Reagan administration insisted that new progress is possible, and that signs of progress would soon be visible.

McGeorge Bundy, John F. Kennedy's national security adviser and formerly president of the Ford Foundation, said he didn't think so. "The prospects for new arms control agreements in the next five years are very low," Bundy said. New American weapons programs would complicate any chances of success, he added.

But Paul C. Warnke, the principal negotiator of SALT II and a man who has often been vilified by conservative opponents of that treaty, many of them members of the Reagan administration, was much more hopeful. Arms control is "an unnatural act," Warnke observed, but there is still momentum behind it.

He suggested that the current "Intermediate Nuclear Forces" negotiations in Geneva, aimed at limiting nuclear weapons deployed in Europe, really amount to a resumption of the SALT talks, or START talks in the Reagan administration's preferred acronym, standing for Strategic Arms Reduction Talks.

Warnke said the Reagan administration's interest in the European talks may have been forced by West European opinion, and the negotiations may have been "conceived in sin," but they have a life of their own and could succeed.

William Hyland, one of Henry Kissinger's closest associates in the Nixon and Ford administrations, took up the same point, arguing that the European negotiations "are probably doomed to succeed."

And if a compromise can be reached on European-based missiles, Hyland added, a new compromise on the intercontinental weapons that are the subject of the SALT or START talks could follow.

The administration has discovered, Hyland said, that it is better to campaign as the "peace candidate" than as the "war candidate." He noted that the administration had both respected the unratified SALT II treaty that Ronald Reagan ran against in 1980 and has declined to "link" continued arms negotiations to acceptable Soviet behavior in other areas.

The administration decided not to suspend the Geneva talks on European weapons after the declaration of martial law in Poland, though it did postpone beginning a new round of START talks on intercontinental weapons because of the Polish events.

The senior representatives of the Reagan administration here indicated that "linkage" would not be invoked to put off further those START talks. Ambassador James Goodby, deputy chief of the administration's delegation to the as-yet-unconvened talks, said the discussions could begin "later in the summer or perhaps in the fall."

Robert Grey, acting deputy director of the Arms Control and Disarmament Agency, suggested "toward the end of the spring."

Neither explained how the impediment created by martial law in Poland would be removed so quickly.

Other participants were much less hopeful. Dmitri Simes, a Russian-born professor at the Johns Hopkins University School for Advanced International Studies, said the administration's "zero option" proposal to eliminate all nuclear ballistic missiles in Europe was so unrealistic that it is unlikely to lead anywhere.

The Soviets, Simes said, are unlikely to be tempted by a proposal to dismantle all 280 of their SS20 rockets in place in return for an American promise not to deploy any comparable rockets in the future. The United States has no comparable weapons now, and doesn't have European approval to deploy any.

In the manner of academic conferences, this one ended with no agreement. The subject--nuclear weapons--was the one contribution to the human condition that could turn this generation into the pariah of all history, but there was no sense of urgency in the discussion.

"Americans show a surprising timidity" about nuclear arms control, observed Alan Neidle, Tom Slick professor of World Peace at the LBJ School and organizer of this meeting. "We are incapable of getting into these negotiations without fearing that we're going to be defeated."