In-situ jet calibration (ATLAS)

The in-situ jet calibration in ATLAS consists of two separate calibrations:

• $\eta$ intercalibration changes the jet transverse momentum in data to make the data-MC response uniform as a function of the jet pseudorapidity $\eta$ (i.e. changes $|\eta| > 0.8$ to match $|\eta| < 0.8$)
• In-situ jet energy scale: changes the jet transverse momentum in data to bring the data-MC response to unity, in bins of transverse momentum (derived in the central region, hence the need for the above)