Naturalness and Fine Tuning in the NMSSM: Implications of Early LHC Results

Ulrich Ellwanger (1) , Grégory Espitalier Noel (2) , Cyril Hugonie (3)

1 LPT - Laboratoire de Physique Théorique d'Orsay [Orsay]
2 L2C - Laboratoire Charles Coulomb
3 LUPM - Laboratoire Univers et Particules de Montpellier

We study the fine tuning in the parameter space of the semi-constrained NMSSM, where most soft Susy breaking parameters are universal at the GUT scale. We discuss the dependence of the fine tuning on the soft Susy breaking parameters M_1/2 and m0, and on the Higgs masses in NMSSM specific scenarios involving large singlet-doublet Higgs mixing or dominant Higgs-to-Higgs decays. Whereas these latter scenarios allow a priori for considerably less fine tuning than the constrained MSSM, the early LHC results rule out a large part of the parameter space of the semi-constrained NMSSM corresponding to low values of the fine tuning.

Domaines: Physique des Hautes Energies - Phénoménologie [hep-ph]

Ulrich Ellwanger, Grégory Espitalier Noel, Cyril Hugonie. Naturalness and Fine Tuning in the NMSSM: Implications of Early LHC Results. Journal of High Energy Physics, 2011, 1109, pp.105. ⟨10.1007/JHEP09(2011)105⟩. ⟨hal-00609283⟩