The ASYMOW project aims at providing a precise measurement of the mass of the W boson, one of the fundamental mediators of the electroweak force.
A precision measurement of this fundamental parameter of Nature is important because it would allow for a stringent test of the Standard Model, the theory which explains the interactions between elementary particles.
More importantly, a possible deviation between the direct measurement of the W boson mass and the value predicted by the SM would indicate the existence of new physics beyond the Standard Model, which in turn could explain some of the puzzles that riddle the current theory.
The novelty of the project lies in the experimental approach proposed to extract the value of the W boson mass.
While all measurements to date made use of selected, but necessarily "smaller", samples of collider data, this project wants to use the full data sample collected by the CMS experiment during the second run of the LHC.
To do so, a new approach, which we called theory-agnostic, is pursued. The idea behind the theory-agnostic approach is to leverage the need for a precise prediction of the W boson production mechanism, which have been so far the limiting factor in the measurement of the mass, by making use of a generic parametrization based solely on quantum-mechanical and geometrical symmetries. This generic model will be then constrained directly from the data, simultaneously with the mass of the W particle.
If all the other experimental systematics will be kept under control, this new approach can circumvent the limiting source of systematic uncertainties, paving the way towards a measurement with less than 10 MeV uncertainty, which would be a primer at the LHC and crucial to corroborate, or discard, the existing tension between theory and experiments.
