Changing patterns in electroweak precision fits with new color-charged states: Oblique corrections and the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>W</mml:mi></mml:math>-boson mass
Linda M. Carpenter, Taylor Murphy, Matthew J. Smylie
Abstract
The recent measurement by the CDF Collaboration of the $W$-boson mass is in significant tension with the Standard Model expectation, showing a discrepancy of seven standard deviations. A larger value of ${m}_{W}$ affects the global electroweak fit, particularly the best-fit values of the Peskin-Takeuchi parameters $S$, $T$ (and perhaps $U$) that measure oblique corrections from new physics. To meet this challenge, we propose some simple models capable of generating non-negative $S$ and $T$, the latter of which faces the greatest upward pressure from the CDF measurement in scenarios with $U=0$. Our models feature weak multiplets of scalars charged under $\mathrm{SU}(3{)}_{\mathrm{c}}\ifmmode\times\else\texttimes\fi{}\mathrm{U}(1{)}_{Y}$, which cannot attain nonzero vacuum expectation values but nevertheless produce, e.g., $T\ensuremath{\ne}0$ given some other mechanism to split the electrically charged and neutral scalars. We compute the oblique corrections in these models and identify ample parameter space supporting the CDF value of ${m}_{W}$.