Forward–backward multiplicity correlations at STAR

Forward–backward multiplicity correlations measured at STAR are discussed. A strong long-range correlation for inclusive charged hadrons was measured as a function of pseudorapidity separation (Δη) in Au+Au collisions at image, and were shown to decrease with decreasing centrality. STAR preliminary results show the correlation strength for pions, kaons, (anti)protons as a function of rapidity separation (Δy) in 0–10% and 10–20% Au+Au collisions at image. The Color Glass Condensate picture, which describes particle sources as longitudinal flux tubes, predicts that the correlation will grow with centrality. Fluctuations in the number of gluons at early times will produce a long-range correlation strength larger for pions than for baryons. A strong, long-range correlation is measured for pions in central collisions, which decreases for 10–20% collisions.