Supersymmetric custodial triplets

We analyze the extension of the minimal supersymmetric standard model which includes extra Y=(0,±1) supersymmetric triplets with a global SU(2) L⊠- SU(2)R symmetry spontaneously broken to the custodial SU(2)V by the vacuum expectation value of the neutral scalar components of doublets and triplets. The model is the supersymmetrization of the nonsupersymmetric model introduced long ago by Georgi and Machacek where the ρ parameter is kept to unity at the tree level by the custodial symmetry. Accordingly, the scalar sector is classified into degenerate SU(2)V multiplets: singlets, triplets (including the one containing the Godstone bosons) and fiveplets. The singly and doubly charged chiral superfields play a key role in the unitarization of the theory. The couplings of the standard model-like Higgs to vector bosons (including γγ) and fermions, and the corresponding Higgs signal strengths, are in agreement with LHC experimental data for a large region of the parameter space. Breaking of custodial invariance by radiative corrections suggests a low-scale mechanism of supersymmetry breaking. © 2013 American Physical Society.