Measurement of colour flow with the jet pull angle in t[bar over t] events using the ATLAS detector at √s = 8 TeV

Abstract

The distribution and orientation of energy inside jets is predicted to be an experimental handle on colour connections between the hard–scatter quarks and gluons initiating the jets. This Letter presents a measurement of the distribution of one such variable, the jet pull angle. The pull angle is measured for jets produced in t[bar over t] events with one W boson decaying leptonically and the other decaying to jets using 20.3 fb[superscript −1] of data recorded with the ATLAS detector at a centre–of–mass energy of √s = 8 TeV at the LHC. The jet pull angle distribution is corrected for detector resolution and acceptance effects and is compared to various models.