Sign of new particle could point to novel physics
Evidence of a new particle at a U.S. particle collider may point to a new force previously unknown to physics.
The evidence comes in the form of an unexpected peak in data collected at the Tevatron particle accelerator at the Fermi National Accelerator Laboratory in Illinois. The collider accelerates protons and antiprotons close to the speed of light, then smashes them head-on into each other, producing signals that might point to new particles produced in the collision.
The peak is linked to the production of a particle called a W boson and two cones of particles called hadronic jets.
The new peak "might be explained by a new, unknown particle that is not predicted by the Standard Model, the current standard theory of the fundamental laws of physics," wrote Elizabeth Clements, senior science communicator for Fermilab, in a blog post Thursday.
That's because the characteristics of the particle show it is definitely not a Higgs boson or a supersymmetric particle — particles that might be expected under the Standard Model.
Instead, it is consistent with some new proposed models of physics that predict the existence of new fundamental interactions between particles "beyond those known today."
The Collider Detector at Fermilab group, a collaboration of scientists who study high-energy particle collisions, announced their discovery on Wednesday.
It has been submitted to the journal Physical Review Letters and posted on the arXiv online archive. However, it has not yet been peer-reviewed.
The researchers are also waiting for experiments at other particle accelerators, such as the Large Hadron Collider, to look for the same peak under similar conditions.
"Their results will either refute or confirm our result," the blog post said.
It is possible that the peak is not caused by a particle. Another possibility is that the method used to find peaks from the data is incorrect. That method uses a theory based on standard particle physics processes to predict what the data would look like if there were no new unknown particle. That is compared to the data researchers actually collect.
"That possibility, albeit less glamorous, would still have important implications. Those calculations use theoretical tools that are generally regarded as reliable and well understood, and form the basis of many other predictions in particle physics," the blog post said.
"Questioning these tools would require us to challenge our understanding of the fundamental forces of nature, the foundation of particle physics."