Prescise measurement of jet energies with the ZEUS detector
  A method to correct the jet transverse energy has been developed for the ZEUS detector which attains an uncertainty better than 3%. The procedure is based on a combination of tracking and calorimeter information that optimises the resolution of reconstructed kinematic variables. The selected calorimeter clusters and tracks are referred to as Energy Flow Objects (EFOs). The conservation of energy and momentum in neutral current deep inelastic $e^+p$ scattering events is exploited to determine the required energy corrections by balancing the scattered positron with the hadronic final state. The method has been applied to data and simulated events independently. The corrected EFOs are used as input to a $k_T$-cluster jet algorithm to reconstruct the jets and to determine kinematic variables. In addition, the corrected EFOs allow an improved measurement of the internal structure of a jet. 
Matthew Wing (On behalf of the ZEUS collaboration)