Some researchers are throwing cold water on the belief that the particle discovered in the Large Hadron Collider two years ago actually is the elusive Higgs boson.
Teams of scientists said last year that the particle, discovered in July 2012, was increasingly looking like the Higgs boson. The physicists studying the find never said they were 100% certain they had identified what's been called the God Particle, but they did say that the more they analyzed it, the more evidence they found supporting their theory.
Now a group of physicists is raising doubts about that.
"The current data is not precise enough to determine exactly what the particle is," said Mads Toudal Frandsen, an associate professor at the Center for Cosmology and Particle Physics Phenomenology, Department of Physics, Chemistry and Pharmacy at the University of Southern Denmark. "It could be a number of other known particles."
Frandsen noted that the scientists have not found proof that the particle is not the Higgs boson. They simply say it's just as likely that it's not.
The skepticism has caused a stir because there was so much excitement in the scientific community when the particle was discovered using the Large Hadron Collider, the world's largest and most powerful particle accelerator.
The Higgs boson, which scientists have been hunting for at least five decades, is a theoretical sub-atomic particle that many believe to be the reason everything has mass. The particle is considered to be a critical building block to everything we know, since without it - without mass -- there would be no structure, and no weight, to anything.
The Higgs boson is an elementary particle in the Standard Model of Particle physics. More plainly said, it's a cornerstone of physics theory.
Physicists Peter W. Higgs, of the University of Edinburgh in Scotland, and François Englert, of the Université Libre de Bruxelles in Belgium, both received the Nobel Prize in physics in 2013, a little more than a year after the particle's discovery, for theorizing about the Higgs in 1964.
Christoph Paus, an MIT physics professor who organized the search for the Higgs in 2012, said it's clear that the collider found a new particle. The question is what exactly it is.
"Nailing this completely down is something that will take a long time," said Paus, who also was one of the many researchers analyzing the data. "Measurements of the particle are not very precise yet.... The new particle appears to match the Higgs from all sides, but our vision at the moment is not perfect, or even close to perfect. There's no reason why it shouldn't be the Higgs, but there's no reason why it couldn't be something else either."
Frandsen and his group of researchers contend that the particle found by CERN, the European Organization for Nuclear Research that runs the collider, could be what's called a techni-higgs -- a particle easily confused with a Higgs boson but one that belongs to a different theory of how the universe was created.
Paus, though, said he would be excited even to learn that the particle isn't a Higgs boson because it would open up a whole new understanding of the universe. "I would love the particle we have found not to be the Higgs," he added. "If it wasn't the Higgs, that would mean there must be much more particles out there and it would be a leap in our understand of all particles, giving us another chance to understand much more about what the world around us is made of.... That would be the first time in a long time that we make a quantum leap in our understanding."
Paus still believes there's a "relatively small likelihood" that what they've found is not the Higgs boson.
The collider, shut down in 2013 for a two-year upgrade, is expected to begin running again early next year, according to CERN.
When that happens, Paus said, scientists will get more particle measurements and learn more about its properties. "That's when the image gets sharper," he said.