Principal component analysis of event-by-event fluctuations

Rajeev S. Bhalerao (1) , Jean-Yves Ollitrault (2) , Subrata Pal (1) , Derek Teaney (3)

1 TIFR - Tata Institute for Fundamental Research
2 IPHT - Institut de Physique Théorique - UMR CNRS 3681
3 SBU - Stony Brook University [SUNY]

We apply principal component analysis to the study of event-by-event fluctuations in relativistic heavy-ion collisions. This method brings out all the information contained in two-particle correlations in a physically transparent way. We present a guide to the method, and apply it to multiplicity fluctuations and anisotropic flow, using ALICE data and simulated events. In particular, we study elliptic and triangular flow fluctuations as a function of transverse momentum and rapidity. This method reveals previously unknown subleading modes in both rapidity and transverse momentum for the momentum distribution as well as elliptic and triangular flows.

Domaines: Physique Nucléaire Théorique [nucl-th]; Physique des Hautes Energies - Phénoménologie [hep-ph]; Physique Nucléaire Expérimentale [nucl-ex]

Rajeev S. Bhalerao, Jean-Yves Ollitrault, Subrata Pal, Derek Teaney. Principal component analysis of event-by-event fluctuations. Physics Letters B, 2015, 114 (15), pp.2301. ⟨10.1103/PhysRevLett.114.152301⟩. ⟨cea-01323613⟩