Exciting new subatomic particle believed to be the fifth force in nature
Why do scientists keep searching for new subatomic particles?
One reason is that there are still many mysteries in our universe that cannot be scientifically explained. These new particles can help scientists find those answers.
Secondly, the knowledge gained from these new particles will eventually evolve into remarkable new technologies in the future. So many things we use daily in our lives today were spawned from understanding molecules and atoms. Now it’s time to look even closer to what they are made from.
Fundamental forces of nature
For quite a while now, physicists have been aware of nature’s four fundamental forces: electromagnetism, gravity, the weak nuclear force, and the strong nuclear force.
They could now be adding a fifth force to that list.
Many experts believe that a fifth force of nature could help solve the mystery surrounding dark matter. Think about the significance of this since dark matter makes up about 85% of our universe’s total mass.
Not only that, this discovery could lead to a unified fifth force theory. This means having one grand universal fundamental force that joins all of the fundamental forces together - which for a long time has been one of the holy grails of particle physics.
Has science uncovered a new fundamental force of nature?
These most recent findings have been built on a study published in 2016 that hinted at the existence of a fifth force.
In this 2015 study, physicists from Hungary’s Institute for Nuclear Research searched for ‘dark photons,’ which they believe carries dark matter. To get a glimpse of these strange forces, the team used a particle accelerator to blast particles through vacuum tubes at very high speeds. Their objective was to see how isotopes decay in high-energy states. Any aberrations in particle behavior under these conditions may indicate the existence of an unknown force.
This research team observed the radioactive decay of beryllium-8, which is an unstable isotope. After beryllium-8 particles decayed, the team witnessed unexpected emissions of light. The positrons and electrons from this unstable isotope repelled one another at precisely 140 degrees. The physical law of conservation of energy claims that this wasn’t supposed to happen – it points to an unknown particle.
A new type of boson
Another research team from the University of California, Irvine (UCI), suggested that this unknown particle wasn’t a dark photon, but instead, it was a boson. Specifically, they called it a ‘protophobic X boson,’ which would indicate a fifth fundamental force of nature. Bosons are particles in quantum mechanics that transport energy, behave as the glue that binds matter together, and control physical forces’ interaction.
It should be pointed out that the fundamental forces typically depend on a boson. Light particles carry the electromagnetic force, the strong force needs gluons, and the weak force is carried by Z and W bosons. This new boson suggested by the UCI research team is unlike any other and could very well indicate a new force. This new boson has a fantastic characteristic of interacting only with neutrons and electrons at very short distances, while the electromagnetic force usually acts on electrons and protons.
The X17 particle
In this new study, which is published on the preprint archive arXiv, the Hungarian research team witnessed similar evidence for this new boson, which they call the X17 particle because its mass is measured to be around 17 MeV (megaelectronvolts). In this case, they used an isotope of helium.
“This feature is similar to the anomaly observed in 8Be and seems to agree with the X17 boson decay scenario,” researchers published in their paper. “We are expecting more independent experimental results to come for the X17 particle in the coming years.”
A ‘revolutionary’ discovery
Finding and understanding this fifth force of nature could give us a glimpse into the mysterious ‘dark sector.’ This dark sector is how scientists refer to unobservable forces in nature that can’t be described using the Standard Model.
For some reason, subatomic particles from this hidden layer of the universe hardly ever interact with the Standard Model’s known particles.
Discovering the fifth force could be the pathway of understanding how these two layers coexist.