Directed and elliptic flow of inclusive photons near mid-rapidity in 158 A GeV Pb + Pb collisions has been studied. The data have been obtained with the photon spectrometer LEDA of the WA98 experiment at the CERN SPS. The flow strength has been measured for various centralities as a function of pT and rapidity over 0.18 < pT < 1.5 GeV/c and 2.3 < y < 2.9. The angular anisotropy has been studied relative to an event plane obtained in the target fragmentation region that shows the elliptic flow to be in-plane. The elliptic flow has also been studied using two-particle correlations and shown to give similar results. A small directed flow component is observed. Both the directed and elliptic flow strengths increase with pT. The photon flow results are used to estimate the corresponding neutral pion flow.
- Deduced neutral pion flow features
- Measured inclusive photons direct and elliptic flow vs. centrality, rapidity and transverse momentum
- Nuclear reactions Pb(Pb, X), E=158 GeV/nucleon
ASJC Scopus subject areas
- Nuclear and High Energy Physics