theoretical physics
june 2015
image sources
QuantumDiaries.org
13
The leptons include the electron, muon, and the tau, along with their neutrino partners. The electron, muon, and tau all have an electric charge and have a sizeable amount of mass. Neutrinos are famous for being nearly massless and traveling at nearly the speed of light, along with having interactions with matter that are so weak (partially due to their neutral charge) that most of the interstellar neutrinos simply pass through Earth.
The force carrying particles carry different forces. Photons carry electromagnetic force. Other forces like the weak force, which operates only at tiny atomic distances and prevents electrons from falling into the positive nucleus of an atom, are carried by the W boson and the Z boson. The strong force, which binds together the quarks in a proton or neutron, operates through the gluon (get it, glue-on?). The last force, not represented in the Standard Model, is the graviton, which carries the force of gravity. The graviton is not represented in the Standard Model because it does not fit very well into the framework of the quantum world - gravity, which is a force that operates over large distances, does not work well with small distances, so physicists typically omit the force of gravity in small interactions such as those that occur in the quantum world.
Finally, there is the Higgs Boson, the “god particle”. This particle interacts with the Higgs Field, which gives everything that has mass its mass. This particle is supremely important too, because it can determine the fate of the universe. Recently, physicists have measured the mass of the Higgs Boson to be around 126 GeV (giga-electron Volts), which puts the universe at the brink of instability. This means that at any moment, if the Higgs Boson suddenly switches to a lower energy state, a new and more empty vacuum can form that will expand at the speed of light, annihilating anything and everything in the universe. A result of this could be that in this new vacuum, only hydrogen can exist in a stable state, with no other atoms being present, or even possible.
Thankfully, theorists aren’t very concerned about this development, as this vacuum decay probably will not happen for billions of years, if ever. Unfortunately, if it does, it will be impossible to stop. And who knows? Maybe it’s already happened and it’s on its way here now. Just goes to further show that you should live each day like it’s your last.
Because it just might be.
sources
home.web.cern.ch
physics.info/standard
Scientific American