Searches for supersymmetric electroweakinos have entered a crucial phase , as the integrated luminosity of the Large Hadron Collider is now high enough to compensate for their weak production cross-sections .
Working in a framework where the neutralinos and charginos are the only light sparticles in the Minimal Supersymmetric Standard Model , we use GAMBIT to perform a detailed likelihood analysis of the electroweakino sector .
We focus on the impacts of recent ATLAS and CMS searches with 36 fb ^ { -1 } of 13 TeV proton-proton collision data .
We also include constraints from LEP and invisible decays of the Z and Higgs bosons .
Under the background-only hypothesis , we show that current LHC searches do not robustly exclude any range of neutralino or chargino masses .
However , a pattern of excesses in several LHC analyses points towards a possible signal , with neutralino masses of ( m _ { \tilde { \chi } _ { 1 } ^ { 0 } } ,m _ { \tilde { \chi } _ { 2 } ^ { 0 } } ,m _ { \tilde { \chi } _ { 3 } ^ { 0 } } ,m _ % { \tilde { \chi } _ { 4 } ^ { 0 } } ) = ( 8–155 , 103–260 , 130–473 , 219–502 ) GeV and chargino masses of ( m _ { \tilde { \chi } _ { 1 } ^ { \pm } } ,m _ { \tilde { \chi } _ { 2 } ^ { \pm } } ) = ( 104–259 , 224–507 ) GeV at the 95 % confidence level .
The lightest neutralino is mostly bino , with a possible modest Higgsino or wino component .
We find that this excess has a combined local significance of 3.3 \sigma , subject to a number of cautions .
If one includes LHC searches for charginos and neutralinos conducted with 8 TeV proton-proton collision data , the local significance is lowered to 2.9 \sigma .
We briefly consider the implications for dark matter , finding that the correct relic density can be obtained through the Higgs-funnel and Z -funnel mechanisms , even assuming that all other sparticles are decoupled .
All samples , GAMBIT input files and best-fit models from this study are available on Zenodo .