Far out cosmology: LHC spots a possible new particle (Introduction)

by David Turell , Friday, April 29, 2016, 15:41 (2916 days ago) @ David Turell

The LHC is about to go back to work after maintenance and upgrades. The hint of a new particle stirs expectations of a breakthrough and this article describes what might be happening. The standard model is not really complete and has many questions, especially what is dark matter?: - https://aeon.co/opinions/physics-is-on-the-verge-of-an-earth-shattering-discovery?utm_s... - "The Higgs boson filled in the last missing piece of the Standard Model, but this model is itself clearly incomplete. None of its particles has the properties of dark matter, a mysterious entity that is five times as prevalent as all the ordinary matter (everything made of atoms, which in turn are built from quarks and electrons) visible in the stars and galaxies. The Standard Model also does not explain the wide range of masses of the fundamental particles, nor why antimatter seems to have nearly completely disappeared, leaving the Universe filled almost exclusively with matter. - "That is why, after spending nearly 60 years building the Standard Model, particle physicists are now terribly excited at the prospect of finally breaking it. The flaws of the model were well known, but no one knows what the right model might be. - *** - "For the first time last year, the LHC produced collisions with an energy of 13 trillion electron volts (TeV), far above the 8 TeV it had achieved before. If new particles exist - beyond the known ones comprised within the Standard Model - that energy upgrade potentially brought them within reach. Given the technical difficulties associated with raising the LHC's operating energy, the data sample accumulated in 2015 was small. Hence, the researchers found just a handful of unusual events. The presence of a new particle can only be confirmed with more data, which should be available by this summer. - "Massive particles are unstable and break down so rapidly that all physicists can see is the trail of secondary decay particles they leave behind. It this case, the trail was an intriguing excess of events containing two photons with a combined mass of 750 billion electron volts (GeV); that is, these pairs of photons all seemed to emerge from an unknown particle six times as massive as the Higgs boson and 800 times the mass of a proton. - *** - "Any new particle or phenomenon that advances physics toward such a grand theory would be more Earth-shattering than the discovery of the Higgs boson or the recent detection of gravitational waves. Both of those had been predicted for many years; finding them was an experimental triumph, but it merely confirmed what was already theoretically understood, and did not deepen our fundamental comprehension of the Universe." - Comment: It has been stated that to fully understand the Big Bang we need an LHC the size of the universe, but it did give us the fine tuning we needed to appear.