The neutral Higgs self-couplings in the (h)MSSM

Understand

We consider the Minimal Supersymmetric extension of the Standard Model in the regime where the supersymmetric breaking scale is extermely large.

• In this MSSM, not only the Higgs masses will be affected by large radiative corrections, the dominant part of which is provided by the third generation quark/squark sector, but also the various self-couplings among the Higgs states.
• In this note, assuming that squarks are extremely heavy, we evaluate the next-to-leading order radiative corrections to the two neutral CP-even Higgs self-couplings $\lambda_{H h h}$ and $\lambda_{h h h}$ and to the partial decay width $\Gamma(H \to h h)$ that are most relevant at the LHC.
• The calculation is performed using an effective field theory approach that resums the large logarithmic squark contributions and allows to keep under control the perturbative expansion.