Standard Model Measurements

The Standard Model (SM) of particle physics has successfully described decades of results from particle colliders with unprecedented accuracy. Making precise measurements of its predictions is one of the best avenues to improving our fundamental understanding and discovering deviations that may point to new physics. The ATLAS experiment at the Large Hadron Collider (LHC) provides an ideal dataset for this, allowing to test particle production up to unprecedented energies and measure the properties of these particles to high precision.

The Liverpool ATLAS SM group focuses on precision studies of W and Z bosons, the carriers of the weak force, in leptonic final states, which can be measured with great precision in the detector and are matched by accurate theoretical predictions. Studying how often W and Z bosons are produced helps us learn more about the structure of the proton, which is made of quarks and gluons. Our work has revealed that strange quarks play a larger role in the proton’s structure than previously thought.  We also study rare events where W and Z bosons are produced with very high energies, probing the limits of SM predictions. These results are carefully corrected for detector effects, so they can be used broadly to test for new physics in a model-independent way. 

We also lead measurement of the W boson mass, which is one of the most challenging endeavours at the LHC.  The W mass is one of the most precisely predicted quantities in the SM and our measurements probe deviations of 1 part in 10,000, which can reveal tiny effects from particles or forces not yet discovered. 

Academic and Research Staff 

  • Prof Uta Klein 
    Dr Jan Kretzschmar 

PhD Students 

  • Mr Samuel Alibocus 
    Mr Josh Newell 

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