Measurement of the production of neighbouring jets in lead–lead collisions at √snn = 2.76 TeV with the ATLAS detector

Abstract

This Letter presents measurements of correlated production of nearby jets in Pb+Pb collisions at √snn = 2.76 TeV using the ATLAS detector at the Large Hadron Collider. The measurement was performed using 0.14nb-1 of data recorded in 2011. The production of correlated jet pairs was quantified using the rate, R≜R, of “neighbouring” jets that accompany “test” jets within a given range of angular distance, ΔR, in the pseudorapidity–azimuthal angle plane. The jets were measured in the ATLAS calorimeter and were reconstructed using the anti-kt algorithm with radius parameters d=0.2, 0.3, and 0.4. R≜R was measured in different Pb+Pb collision centrality bins, characterized by the total transverse energy measured in the forward calorimeters. A centrality dependence R≜R of is observed for all three jet radii with R≜R found to be lower in central collisions than in peripheral collisions. The ratios formed by the R≜R values in different centrality bins and the values in the 40–80% centrality bin are presented.