The LHC Starts 13 TeV Collisions

Collisions at the LHC have started again and are now at a center of mass energy of 13 TeV for protons on protons. This was the target energy for the upcoming physics run this year, so this means that the accelerator group was successful in getting everything up to the desired energy. It’s still a little bit lower than the design energy of 14 TeV, but is much better than the 7-8 TeV that the initial runs used. The extra energy allows for a lot of analyses to be done better. Searches for exotic particles can reach a wider range of masses. While cross sections for most processes fall with energy, it is also the case that for some important analyses the backgrounds fall faster than the signal. Thus, a better measurement can be made with lower statistics because the sample has a better purity.