“Physics has been solved!” many scientists declared upon the announcement that gravitational waves had been detected in February of this year, confirming Einstein’s theory of relativity. However, a new observation in the field of particle physics has threatened to shake the scientific world yet again. In an article published in the January issue of the Physical Review Letters, a group of Hungarian physicists unveiled the detection of an unknown particle, unaccounted for by the Standard Model.

Ever since the 1930’s, physicists have accepted the Standard Model of particle physics, which propounds the existence of four fundamental forces in nature: gravity, electromagnetism, and the strong and weak nuclear forces. The strong nuclear forces hold the nucleus intact against the repulsion of positively-charged protons, while the weak nuclear forces play a role in radioactive decay. This widely-accepted theory is now being challenged by the possible existence of the “protophobic X boson.”

The possibility of this new fifth particle was first realized by a team of Hungarian physicists from the Hungarian Academy of Science’s Institute of Nuclear Research last year. The team, led by Attila Krasznahorkay, bombarded lithium-7 nuclei with protons, creating beryllium-8 nuclei.  As the newly-formed, high-energy beryllium nuclei decayed, the scientists detected an unexpected anomaly in the energies of the radiated particles. Instead of emitting just electrons and positrons, the nuclei were also emitting particles with a different energy. In their published paper, the team suggested the possible existence of a “dark photon,” the dark matter version of the photon. Dark matter is essentially matter that we cannot detect, since it does not interact with light. Its existence is inferred from its gravitational effects on light matter.

After about a year since the Hungarian team’s discovery, a team led by Jonathan Feng at the University of California, Irvine brought the findings to the forefront again by proposing that the newly detected particle could be a “protophobic X boson” rather than a dark photon. This was due to the fact that products of a protophobic X boson decay would split apart at an angle similar to that detected experimentally. The particle is predicted to exert a force over the width of an atomic nucleus, which would make it a fifth force of nature.

The confirmation of this new fifth particle would completely change our current understanding of particle physics.

Currently, the experiments conducted by the Hungarian team are being reproduced by the Thomas Jefferson National Accelerator Facility in Virginia. It is projected that results will be collected within a year. The confirmation of this new fifth particle would completely change our current understanding of particle physics. This discovery would lead to the reinterpretation of the formation of our universe, since scientists would have to factor in a fifth force coming into play. Until then, we can only dream of the multitude of possibilities.

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Olivia Long