Extended Data Fig. 1: Angular observables.
From: Determination of the spin and parity of all-charm tetraquarks
The production and decay of a resonance X in proton collisions pp → X → V1V2 → 4μ define the angular observables in the centre-of-mass frames of the corresponding particles35,46, where the V1 and V2 refer to the J/Ψ mesons. The z axis approximates the proton beam line, while the \(z{\prime} \) axis corresponds to the direction of the four-muon system.
