Speaker
Description
The 750-760 GeV diphoton resonance may be identified as one or two scalars and/or
one or two pseudoscalars contained in the two singlet superfields $S_{1,2}$
arising from the three 27-dimensional representations of $E_6$. We study the corresponding collider signature within the exceptional supersymmetric standard model (E$_6$SSM). This model is based on the SM gauge group together with an extra $U(1)_N$ gauge symmetry under which right--handed neutrinos have zero charge. To ensure anomaly cancellation the low energy matter content of the E$_6$SSM involve three $27$ representations of $E_6$. Thus E$_6$SSM predicts $Z'$ boson and extra matter beyond the MSSM. In particular, the low--energy spectrum of the E$_6$SSM involves three families of Higgs--like doublets,three families of exotic quarks and three SM singlets $S_i$ that carry $U(1)_{N}$ charges. The E$_6$SSM Higgs sector contains one family of the Higgs--like doublets and one SM singlet $S_3$ that develops vacuum expectation values (VEV) breaking $U(1)_N$ gauge symmetry and inducing masses of exotic states mentioned above. The fermion and scalar components of other Higgs--like superfields form Inert Higgsino and Inert Higgs states respectively. Two lighter singlets $S_{1,2}$
with masses around 750 GeV can couple to Inert Higgsino and exotic quarks giving rise to diphoton excess. We calculate the branching ratios and cross-sections for the two scalar and two pseudoscalar states associated with the $S_{1,2}$ singlets, including possible degeneracies and maximal mixing, subject to the constraint that their couplings remain perturbative up to the unification scale.
