WHY SHOULD WE CARE ABOUT THE TOP QUARK YUKAWA COUPLING?
Bezrukov F., Shaposhnikov M.

Received: November 5, 2014

DOI: 10.7868/S0044451015030015

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In the cosmological context, for the Standard Model to be valid up to the scale of inflation, the top quark Yukawa coupling y_t should not exceed the critical value y_t^crit, coinciding with good precision (about 0.2 ) with the requirement of the stability of the electroweak vacuum. So, the exact measurements of y_t may give an insight on the possible existence and the energy scale of new physics above 100 GeV, which is extremely sensitive to y_t. We overview the most recent theoretical computations of y_t^crit and the experimental measurements of y_t. Within the theoretical and experimental uncertainties in y_t, the required scale of new physics varies from 10⁷ GeV to the Planck scale, urging for precise determination of the top quark Yukawa coupling. Contribution for the JETP special issue in honor of V. A. Rubakov's 60th birthday