Curvature-bias corrections using a pseudomass method

The LHCb collaboration

Research output: Indexed journal article Articlepeer-review


Momentum measurements for very high momentum charged particles, such as muons from electroweak vector boson decays, are particularly susceptible to charge-dependent curvature biases that arise from misalignments of tracking detectors. Low momentum charged particles used in alignment procedures have limited sensitivity to coherent displacements of such detectors, and therefore are unable to fully constrain these misalignments to the precision necessary for studies of electroweak physics. Additional approaches are therefore required to understand and correct for these effects. In this paper the curvature biases present at the LHCb detector are studied using the pseudomass method in proton-proton collision data recorded at centre of mass energy √s = 13 TeV during 2016, 2017 and 2018. The biases are determined using Z → μ+μ- decays in intervals defined by the data-taking period, magnet polarity and muon direction. Correcting for these biases, which are typically at the 10-4 GeV-1 level, improves the Z → μ+μ- mass resolution by roughly 18% and eliminates several pathological trends in the kinematic-dependence of the mean dimuon invariant mass.

Original languageEnglish
Article numberP03010
JournalJournal of Instrumentation
Issue number3
Publication statusPublished - 1 Mar 2024


  • Analysis and statistical methods
  • Detector alignment and calibration methods (lasers, sources, particle-beams)
  • Large detector-systems performance
  • Performance of High Energy Physics Detectors


Dive into the research topics of 'Curvature-bias corrections using a pseudomass method'. Together they form a unique fingerprint.

Cite this