Detail of the large hadron collider
March 10, 2016

LHC discovery could lead to fifth fundamental force, breakdown of standard model

The discovery of a particle six times heavier than the Higgs boson during December experiments at the Large Hadron Collider (LHC) suggests that there may be a new set of particles, and maybe even a fifth fundamental force not described by the standard model of particle physics.

The particle in question is known as the B meson, and according to ScienceAlert and the Daily Mail, the standard model dictates that it should have to decay at specific angles and frequencies. However, what researchers at the European Organization for Nuclear Research (CERN)  found during their experiments did not match-up with predictions of the particle’s behavior.

“Up to now all measurements match the predictions of the standard model. However, we know that the standard model cannot explain all the features of the Universe,” lead researcher Mariusz Witek of the Institute of Nuclear Physics of the Polish Academy of Sciences said in a statement, adding that there are many questions that have been left unanswered under the standard model, including how matter became dominant over antimatter.

In the case of the B mesons, the newfound particle would be influencing how it decays. While CERN researchers emphasize that it is too early to definitively say that this is a new discovery, if confirmed, it would be “completely beyond the Standard Model, and the tip of an iceberg of a large new set of particles,” John Ellis, a theoretical physicist at King’s College London, told the Daily Mail.

Additional experiments set for April could confirm the discovery

Two detectors at the Geneva-based particle collider, ATLAS and CMS, were on the hunt for new physics by counting particle decays resulting in two photons last December when they produced data hinting at the existence of a particle six-times heavier than the Higgs boson, reports indicate. Both experiments saw photons with a combined energy of 750 gigaelectronvolts (GeV).

As Einstein’s equations dictate, particles release energy equivalent to their mass multiplied by the speed of light squared when they decay into photons. This means that the particle produced by these photons may be a yet unidentified particle with this precise amount of energy in the form of its mass. However, CERN noted that the readings may also just be an irregularity in the measurements, and plan to conduct additional experiments in April to find out for sure.

If this new particle does in fact exist, it would be a major discovery. Its existence had not been predicted by the Standard Model, which states that everything in the universe is made from the building blocks known as fundamental particles and that those particles are governed by a group of four fundamental forces (gravity, electromagnetic, weak nuclear and strong nuclear). The new particle would not fit into the Standard Model’s description, opening up the possibility that there is a new set of undiscovered particles out there waiting to be found.

In addition, the research suggests that there may even be a fifth fundamental force that we don’t yet know about. Ellis told the Daily Mail that this is “possible, but there must at least be a set of unknown particles to explain how this new particle decays, and probably how it is produced.” To confirm this as a new discovery, ScienceAlert said that CERN needs to hit a standard deviation above 5 sigma, meaning there is a less than one-in-3.5 million chance of an error. Their current standard deviation is 3.4 sigma.

“To put it in terms of the cinema, where we once only had a few leaked scenes from a much-anticipated blockbuster, the LHC has finally treated fans to the first real trailer,” Witek added. He and his colleagues have published their findings in the Journal of High Energy Physics.


Image credit: CERN/NASA APOD