Study of Radial Distortions in the ATLAS Inner Detector in the $J/\psi$ Momentum Scale

The measurement of the $W$-boson mass relies on the precise calibration of the muon-momentum scale as measured by the ATLAS tracking detector. Alignment distortions and their associated curvature biases represent an important limitation for the measurement of the muon-momentum scale. In particular, radial distortions are responsible for charge-independent curvature biases. A precise determination and correction of such tracking curvature biases can be performed using samples of $J/\psi$ particles decaying into muon pairs. This project focuses on new methodologies based on the angular analysis of muon pairs, in which a proxy of the scattering angle is used as main observable. The new technique allows the disentanglement of alignment radial distortion biases from magnetic field biases. The application of this methodology will have an impact on $Z$- and $W$-boson mass measurements in ATLAS.