Status and prospects of the nMSSM after LHC Run 1

International audienceThe new minimal supersymmetric standard model (nMSSM), a variant of thegeneral next to minimal supersymmetric standard model (NMSSM) without $Z_3$symmetry, features a naturally light singlino with a mass below 75 GeV. Inlight of the new constraints from LHC Run-1 on the Higgs couplings, sparticlessearches and flavour observables, we define the parameter space of the modelwhich is compatible with both collider and dark matter (DM) properties. Amongthe regions compatible with these constraints, implemented through NMSSMTools,SModelS and MadAnalysis 5, only one with a singlino lightest supersymmetricparticle (LSP) with a mass around 5 GeV can explain all the DM abundance of theuniverse, while heavier mixed singlinos can only form one of the DM components.Typical collider signatures for each region of the parameter space areinvestigated. In particular, the decay of the 125 GeV Higgs into light scalarsand/or pseudoscalars and the decay of the heavy Higgs into charginos andneutralinos, provide distinctive signatures of the model. Moreover, thesfermion decays usually proceed through heavier neutralinos rather thandirectly into the LSP, as the couplings to the singlino are suppressed. We alsoshow that direct detection searches are complementary to collider ones, andthat a future ton-scale detector could completely probe the region of parameterspace with a LSP mass around 65 GeV