https://phys.org/news/2018-07-quarks-interact-minuscule-weak-lightsabers.html

One of the key motivations for building the Large Hadron Collider (LHC) at CERN was to study exactly this process, called weak "vector boson scattering" (VBS). One quark in each of two colliding protons has to radiate a W or a Z boson. These extremely short-lived particles are only able to fly a distance of 0.1x10-15m before transforming into other particles, and their interaction with other particles is limited to a range of 0.002x10-15m. In other words, these extremely short "weak lightsabers" extend only about 1/10th of a proton's radius and have to approach each other by 1/500th of a proton's radius! Such an extremely improbable coincidence happens only about once in 20,000 billion proton-proton interactions, recorded typically in one day of LHC operation.

Using 2016 data, ATLAS has now doubtlessly observed WZ and WW electroweak production, with the dominant part of it being the weak vector boson scattering: W±W± → W±W± and W±Z → W±Z. This continues the experiment's long journey to scrutinise the VBS process: using 8 TeV data from 2012, ATLAS had obtained the first evidence for the W±W± → W±W± process with 18 candidate events. Such a yield would occur with a probability of less than 1:3000 as a pure statistical fluctuation. Now, at a higher centre-of-mass energy of 13 TeV, ATLAS has identified 60 W±W± → W±W± events, which only would happen less than once in 200 billion cases as a fluctuation from pure background processes. This corresponds to a statistical significance of 6.9 standard deviations (σ) above background. Besides the decay products of the scattered W or Z bosons, the signature of the process are two high-energetic particle jets originating from the two quarks that initially radiated the W or Z.