A novel method for lepton energy calibration at Hadron Collider Experiments

TL;DR

This paper introduces an improved lepton energy calibration method for Hadron Collider Experiments that enhances precision by using multiple parameters and additional constraints, while remaining computationally efficient.

Contribution

The novel calibration method extends the classic approach by incorporating more parameters and constraints, reducing correlations and increasing accuracy.

Findings

Improved calibration precision with multiple parameters.

Enhanced constraints by separating decay kinematics.

Faster and easier calibration process.

Abstract

This report is to provide a novel method for the lepton energy calibration at Hadron Collider Experiments. The method improves the classic lepton energy calibration procedure widely used at hadron collider experiments. The classic method parameterizes the potential bias in the lepton en- ergy calibration, and determines the value of the parameter by the invariant mass of $Z/\gamma^*\rightarrow \ell^+\ell^-$ events. The precision of the calibration is dominated by the number of parameters or terms consid- ered in the parameterization, for example, a polynomial extension. With one physics constraint of the reconstructed Z boson mass, the classic procedure can use and determine one parameter. The novel method improves the precision of lepton calibration by introducing more terms in the parameterization. To precisely determine the values of multiple parameters, the method first ac- quires more constraints by separating the $Z/\gamma^*\rightarrow \ell^+\ell^-$ samples according to the decay kinematics, and then reduces the correlation between multiple parameters. Since the new method is still using the reconstructed Z boson masses as the only constraints, it is much faster and easier than detailed study of detector simulations.