Pretty much every physics textbook could go out of date in the (not so distant) future. Physicists might have tantalising evidence of a fifth fundamental force of nature. According to particle physics, there are four fundamental forces, namely Electromagnetism, Gravitation, the Weak force and the Strong force. In terms of strength, the Strong force ranks at the top, while gravitation secures the second position, followed by the Weak force and finally Gravitational force.
Before moving on to the fifth force of nature, it would be convenient to understand the already known forces and their effects on the bodies present in the universe Electromagnetism, the Strong and the Weak forces have particles associated with them called bosons, which are the force-carriers: Gravity is yet to be integrated into the Standard Model, but is thought to have a force-carrying particle known as Graviton.
Strong force has its effects at a sub-atomic level where it binds together very tiny particles, even smaller than electrons and protons. Strong force is experienced by particles known as quarks and gluons. Gluons(g) are also the carrying particles for Strong force Electromagnetism acts between electrically charged particles. The force carrying particle is known as photon(y). Weak force governs a phenomenon known as particle decay. This force is experienced by quarks and leptons. The force carrying particles are W-W-and 20(w and 2). Gravitational acts between, and is experienced by any particle with mass. The force carrying particle has been named Graviton as mentioned before. Unfortunately, it has not been observed by humans, yet. It has been found that electromagnetism and gravitation have an infinite range in which they can act. On the other hand, theStrong and the Weak force act in a small scale and have a very short range where they can influence a particle.
Last year, a group of Hungarian researchers spotted an unusual radioactive decay signal while searching for evidence of 'dark photons', a hypothetical particle proposed to be the electromagnetic force-carriers for dark matter. The signal appeared to have come from an unknown particle just thirty times the mass of an electron.
After combing through the data and several other extremely minute details, physicists at the University of California, Irvine in the US have proposed the origin of the previously mentioned signal to be from a 'photophobic X boson', so called as it only interacts with electrons and neutrons, over an extremely limited range, but not protons. If they are correct, the finding would mean that there is a fifth force operating alongside the electromagnetic and strong and weak nuclear forces, and possibly the existence of a separate dark sector with its own matter and forces. It also might be possible that the normal and dark sectors interact with each other through somewhat veiled but fundamental Interactions.
If the stated particles existence can be confirmed by further experiments, then it would mean the discovery of a possible fifth force which would completely change the understanding of the universe by the human mind. The dark sector may manifest itself as the photophobic force that was seen in the Hungarian experiment. This finding could be a significant step towards understanding the true nature of dark matter and its unification with the fundamental forces.
Amity University, Kolkata