Go to the Indico Home Page Up to category Newer event Newest event Printable version
  • Indico style
  • Indico style - inline minutes
  • Indico style - numbered
  • Indico style - numbered + minutes
  • Indico Weeks View
    • Switch to the management area of this event
    Login

    Cavendish HEP Seminars: Measurement of the Z boson mass with the LHCb detector

    → Europe/London
    Ray Dolby Centre Seminar Room B, B2.002

    Ray Dolby Centre Seminar Room B, B2.002
    Matthew David Monk (University of Cambridge (GB)), Nikolai Fomin (University of Cambridge (GB))
    Description

    In the Standard Model, the Z boson acquires its mass of around 91 GeV through its gauge interaction with the vacuum energy of the Higgs field. Including higher order corrections the Z mass is predicted with a precision of better than 10 MeV, which corresponds to one part in 10,000. The Z mass was measured to 2 MeV by the four LEP experiments in a beam-energy scan of the LEP e+e- collider. Meanwhile, hadron collider experiments have dominated the measurements of the W boson mass, but their studies of the Z boson mass have been primarily in the context of calibrations for the W mass analyses.

    Here we present the first dedicated Z boson mass measurement in proton-proton collisions.

    The data were recorded in 2016 by the LHCb experiment and correspond to an integrated luminosity of 1.7 fb-1. The Z mass is determined from a fit to the dimuon mass distribution in Z -> mu+mu- decays. Templates from simulation are used in the fit, with a momentum calibration based on quarkonium resonance decays. The result is compared with previous measurements of the Z mass and with the predicted value from the global electroweak fit.