Upcoming Events

Precise Estimates of the Higgs Mass in Heavy SUSY

February 25, 2014 3:00PM to 4:00PM
Gabriel Lee, University of Chicago
Building 362, Room E188
HEP Theoretical Physics Seminar
In supersymmetric models, very heavy stop squarks introduce large logarithms into the computation of the Higgs boson mass. Although it has long been known that in simple cases these logs can be resummed using effective field theory techniques, it is technically easier to use fixed-order formulas, and many public codes implement the latter. We calculate three- and four-loop NNLL corrections to the Higgs mass and compare the fixed order formulas numerically to the resummation results in order to estimate the range of SUSY scales where the fixed-order results are reliable.

We find that the four-loop result may be accurate up to a few tens of TeV. We confirm an accidental cancellation between different three-loop terms, first observed in Martin (2007), and show that it persists to higher scales and becomes more effective with the inclusion of higher radiative corrections. Existing partial three-loop calculations that include only one of the two cancelling terms may overestimate the Higgs mass. We give analytic expressions for the three- and four-loop corrections in terms of Standard Model parameters and provide a complete dictionary for translating parameters between the SM and the MSSM and the MS-bar and DR-bar renormalization schemes.