Electroweak vacuum stability and finite quadratic radiative corrections

Preprint number: CP3-Origins-2015-5 DNRF90 and DIAS-2015-5
Authors: Isabella Masina (Ferrara U. & INFN, Ferrara & CP3-Origins & DIAS), Germano Nardini (DESY & Santa Barbara, KITP), and Mariano Quiros (Barcelona, IFAE & ICREA, Barcelona)
External link: arXiv.org

If the Standard Model (SM) is an effective theory, as currently believed, it is valid up to some energy scale $\Lambda$ to which the Higgs vacuum expectation value is sensitive throughout radiative quadratic terms. These can destabilize the electroweak vacuum and generate the SM hierarchy problem. For a given perturbative Ultraviolet (UV) completion, the SM cutoff can be computed in terms of physical masses. If the UV mass spectrum involves several scales the cutoff is not unique and each sector has its own UV cutoff $\Lambda_i$. We have performed this calculation assuming the Minimal Supersymmetric Standard Model (MSSM) is the SM UV completion. As a result, from the SM point of view, the quadratic correction to the Higgs mass is equivalent to finite threshold contributions. For the measured values of the top quark and Higgs masses, and depending on the values of the different cutoffs $\Lambda_i$, these contributions can cancel even at TeV scales, unlike the case of a unique cutoff where the cancellation occurs at Planckian energies. Gauginos heavier than squarks tend to be favored. From the UV MSSM point of view, the quadratic sensitivity is incorporated into the matching conditions and for instance it provides an extra constraint on the Focus Point solution to the little hierarchy problem in the MSSM.