New Delhi, March 7: A third tantalising hint for the existence of an elusive subatomic particle called the Higgs boson has emerged from experiments in a particle accelerator in the US, scientists announced today at a conference in Italy.

The experiments at the Fermi National Accelerator Laboratory [Fermilab] in the US have detected what could be signatures of a Higgs boson with a mass about 115 to 135 times heavier than the mass of a hydrogen atom, the researchers said.

“This is the third hint that a Higgs around 125 GeV exists,” said Gregorio Bernadi, a physicist from the University of Paris who is a spokesperson for one of the experiments at Fermilab. The earlier two hints had emerged in mid-December from two experiments at the Large Hadon Collider, a giant particle accelerator at the European Organisation for Nuclear Research, or Cern, in Geneva.

The Higgs boson is the final missing piece of an elegant theory of physics that explains virtually all known forces and interactions, except gravity. It belongs to a family of particles named after Indian physicist Satyendranath Bose.

The Higgs boson, like many other subatomic particles, is expected to have a fleeting lifetime, tiny fractions of microseconds, before it decays into other particles. The LHC experiments had reported finding Higgs through two similar types of decay channels.

“Now the Fermilab experiments are showing a similar [signal] through another decay mode, the decay of the Higgs boson into two b-quarks,” Bernardi said. “This is by far the dominant decay mode for a Higgs boson of this mass, so it is crucial also to have hints that the Higgs decays in the dominant mode,” Bernardi told The Telegraph. “From this point or view, we could say we’re twice more confident that the Higgs exists around this mass,” he said.

But physicists caution say they cannot say yet that they have found the Higgs boson.

“This is the strongest hint up to now,” Giovanni Punzi, a physicist from the University of Pisa, Italy, who is also working at Fermilab told The Telegraph. But the new results are similar in significance to the LHC findings reported in December, he said.

Fermilab said in a statement physicists claim evidence of a new particle only if the probability that the data is due to statistical fluctuation is less than 1 in 740, also called 3 sigma. A discovery is claimed when the probability is less than 1 in 3.5 million, or 5 sigma.

The new experimental hints thus far are rated at 2.2 sigma to 2.6 sigma.