Long-range pseudorapidity dihadron correlations in d + Au collisions at √sNN = 200 GeV

Dihadron angular correlations in d + Au collisions at √sNN = 200 GeV are reported as a function of the measured zero-degree calorimeter neutral energy and the forward charged hadron multiplicity in the Au-beam direction. A finite correlated yield is observed at large relative pseudorapidity (δη) on the near side (i.e. relative azimuth δϕ~0). This correlated yield as a function of δη appears to scale with the dominant, primarily jet-related, away-side (δϕ~π) yield. The Fourier coefficients of the δϕ correlation, Vn=〈cos n δ ϕ〉, have a strong δη dependence. In addition, it is found that V1 is approximately inversely proportional to the mid-rapidity event multiplicity, while V2 is independent of it with similar magnitude in the forward (d-going) and backward (Au-going) directions. © 2015 The Authors.