Parton showers and QCD jets at high-energy colliders
When a high-energy quark or gluon is produced in a collision, it undergoes a parton shower — a cascade of gluon emissions (q→qg) and gluon splittings (g→gg, g→qq̄) governed by the DGLAP evolution equations. This shower continues until the scale falls to ~1 GeV, then hadronization converts the partons into observable hadrons forming a collimated spray called a jet. At the LHC, jets from TeV-scale processes are the primary signature of new physics searches.