  We investigate the phenomenological implications of the recent $W$ mass
measurement by the CDF collaboration, which exhibits tension with the standard
model (SM) electroweak fit. Performing the fit to the electroweak observables
within the SM effective field theory, we find that the new physics that
contributes either to the determination of the electroweak vacuum expectation
value, or to the oblique parameters, can improve the agreement with data. The
best description is obtained from a fit where flavor universality is not
required in the new physics operators, with 2 to 3 $\sigma$ indications for
several nonzero Wilson coefficients. We point out that top partners with order
TeV masses could lead to the observed shift in the $W$ mass.

High Energy Physics - Phenomenology