New theory may explain proton stability and dark matter

New Scientist : Supersymmetry is a popular extension of the standard model, but some of the particles predicted by the theory have yet to be found by the experiments at the Large Hadron Collider (LHC). A new theory developed by Bartosz Fornal and Tim Tait of the University of California, Irvine, presents an alternative that may also be testable at the LHC. Fornal and Tait were attempting to understand why protons have never been seen to decay. Drawing a parallel with the stability of electrons, which don’t decay because of the conservation of charge, the researchers proposed that protons don’t decay because of the conservation of another particle property: the baryon number. Much like the conservation of electrical charge has been related to the electromagnetic force, Fornal and Tait decided the conservation of baryon number must be related to some other, as-yet-unknown, force. Building on the current theory that all of the other forces were unified for a very short period of time after the Big Bang, their theory suggests that as the forces separated, the strong nuclear force and the baryon number force split. For the theory to work, the researchers had to add new particles having properties currently associated with dark matter. According to the model, the number of those particles that would have been created in the early universe could account for the existing effects of dark matter. Although the LHC is not powerful enough to create such particles, it might be able to create other particles related to them that could be detected.