Yes, I read early today with interest about this POSSIBLE 5th Force in Physics.
The evidence is a bit tenuous, as it involves light emission from 1 or 2 isotopes that goes at unusual or unexpected angles when electrons drop back to a lower energy level in the atom.
This is a good article on this topic by HitRed, with links. However, Dark Matter makes up about 25% of the universe; the vast majority is Dark Energy (about 70%). Here is ONE of many sources on this "Matter."
https://www.nationalgeographic.com/science/space/dark-matter/#closeThe visible universe—including Earth, the sun, other stars, and galaxies—is made of protons, neutrons, and electrons bundled together into atoms. Perhaps one of the most surprising discoveries of the 20th century was that this ordinary, or baryonic, matter makes up less than 5 percent of the mass of the universe.
The rest of the universe appears to be made of a mysterious, invisible substance called dark matter (25 percent) and a force that repels gravity known as dark energy (70 percent).
A 'no-brainer Nobel Prize': Hungarian scientists may have found a fifth force of nature
By Ryan Prior, CNN
6 hrs ago
November 23, 2019
https://www.msn.com/en-us/news/technology/a-no-brainer-nobel-prize-hungarian-scientists-may-have-found-a-fifth-force-of-nature/ar-BBXcgsR?li=BBnbfcL&ocid=mailsignoutNew research may be leading us closer to one more.
Scientists at the Institute for Nuclear Research at the Hungarian Academy of Sciences (Atomki) have posted findings showing what could be an example of that fifth force at work.
The scientists were closely watching how an excited helium atom emitted light as it decayed. The particles split at an unusual angle, 115 degrees, which couldn't be explained by known physics.
Here is more:
https://science.sciencemag.org/content/347/6226/1100JP4Fun
