Animations of showering

Animations of showering can be useful in order to obtain a space-time picture of how collider events are produced and evolve. The animations on this page are produced as follows

• A hadron-level event is generated with Pythia 8
• The event is clustered with with the e⁺e^- genaralised-k_t algorithm with p=0.5 in FastJet. That gives a clustering sequence that is ordered in formation time. (For on-shell Higgs and Z-boson decays, the boson decay time is built in manually).
• The clustering sequence is then sampled at different times to represent particles as traces.
• Initial particles are yellow traces, intermediate particles are shown in blue, final particles (mostly hadrons) are in red. Brighter lines have higher energy.

For more info, see the FAQ below.

3 TeV e⁺e^- → qqbar event

3 TeV e⁺e^- → HZ(→ hadrons)

FAQ

• Why not directly use a parton shower that is ordered in time? Most showers, including the current PanScales ones, don't have that as an option (one exception is Deductor).
• Why only e⁺e^- (and at such high energy)? We are still thinking about how best to represent the initial-state radiation, but at the same time wanted to show events with energies comparable to LHC collisions.
• Is the code to generate these animations public? Not yet, but we hope it will be soon.