TH BSM Forum

Fine-tuning in SUSY

by Anibal Medina (The University of Melbourne)

Thursday, 20 March 2014 from to (Europe/Zurich)
at CERN ( 4-2-011 - TH common room )
Description
We analysed from a bottom-up approach the level of tuning in the MSSM and in the NMSSM associated with the measured 126 GeV Higgs mass, direct searches of superpartners and collider measurements of the Higgs couplings to fermions and gauge bosons. In particular we show that in the scale invariant NMSSM, TeV-scale stop masses are still allowed in much of the parameter space with 5 $\%$ tuning for a low messenger scale, split families and a Higgs-singlet coupling $\lambda$ of order one. In the absence of deviations of the Higgs couplings to fermions and massive gauge bosons from SM values at the LHC and in future colliders, we noticed that there is an  additional independent tuning due to the "SM-likeness" requirement,  which can be naturally suppressed in the MSSM for large values of $\tan\beta$ but that in the scale invariant NMSSM for a coupling $\lambda$ of order one can be the dominant source of tuning.