GENEVA, Feb 10 (Reuters) - For the first time, physicists have created a new form of matter by recreating the conditions thought to have existed 10 microseconds after the Big Bang at the start of the universe, scientists announced on Thursday.

The European Laboratory for Particle Physics (CERN), based outside Geneva, said scientists from more than 20 countries conducted a series of experiments which smashed together heavy lead ions in a fireball to prove a theory that had only existed on paper for years.

By generating collisions at temperatures 100,000 times as hot as the sun's centre and at energy densities never before reached in laboratory experiments, they succeeded in isolating tiny components called quarks from more complex particles such as protons and neutrons, CERN said in a report.

This provided "compelling evidence" for the existence of a new state of nuclear matter, a quark-gluon plasma, which CERN described as "the primordial soup in which quarks and gluons existed before they clumped together as the universe cooled down".

According to CERN, the breakthrough in the project affectionately known as the "Little Bang", is an important step in understanding the early state of the universe, created some 12 to 15 billion years ago in a massive explosion, or Big Bang.

"A series of experiments using CERN's lead beam have presented compelling evidence for the existence of a new state of matter 20 times denser than nuclear matter, in which quarks, instead of being bound up into more complex particles such as protons and neutrons, are liberated to roam freely," it said.

"Such a state must have existed just a few microseconds after the Big Bang, before the formation of particles of matter as we know them today," it added.

DISCOVERY OPENS UP NEW TERRITORY

Some 350 scientists from institutes in 20 countries took part in seven large experiments linked to CERN's accelerator and its lead beam programme which began in 1994.

The institutes, in the Czech Republic, France, India, Italy, Germany, Sweden and Switzerland, measured aspects of the invisible collisions, such as their electromagnetic radiation.

"The combined data coming from the seven experiments on CERN's heavy ion programme have given a clear picture of a new state of matter," said Luciano Maiani, director-general of the 20-member state CERN.

"This result verifies an important prediction of the present theory of fundamental forces between quarks. It is also an important step forward in the understanding of the early evolution of the universe," the Italian physics professor added.

The discovery achieved at Europe's particle physics research centre, a sprawling complex straddling the Swiss-French border, provides strong incentive for future planned experiments to "definitively confirm" the quark-gluon explanation, CERN said.

The focus of research on quark-gluon matter now shifts to the United States. A national laboratory at Brookhaven on Long Island in New York plans to begin its own experiments this year.

"There is still an entirely new territory to be explored concerning the physical properties of quark-gluon matter," Maiani said. "The challenge now passes to the Relativistic Heavy Ion Collider at the Brookhaven National Laboratory and later to CERN's Large Hadron Collider."