First high-precision measurement of the mass of the W-boson at the LHC
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In a paper published on 6 February in the European Physical Journal C, the ATLAS Collaboration reports the first high-precision measurement at the Large Hadron Collider (LHC) of the mass of the W boson.
The reported result gives a value of 80370±19 MeV for the W mass, which is consistent with the expectation from the Standard Model of Particle Physics.The measurement is based on around 14 million W bosons recorded in a single year (2011), when the LHC was running at the energy of 7 TeV. The W is one of the particles that mediate the weak interaction – one of the forces that govern the behaviour of matter in our universe — and one of the heaviest known elementary particles.
In the words of Tancredi Carli, physics coordinator of the ATLAS Collaboration, to achieve such a precision only one year of Run 1 data was “great challenge” and gives "an extremely
promising indication of our ability to improve our knowledge of the Standard Model and look for signs of new physics through highly accurate measurements.”
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