Neutralinos are unknown mixtures of photinos, z-inos, and neutral higgsinos (the supersymmetric partners of photons and of ${{\mathit Z}}$ and Higgs bosons). The limits here apply only to ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$, ${{\widetilde{\mathit \chi}}_{{3}}^{0}}$, and ${{\widetilde{\mathit \chi}}_{{4}}^{0}}$. ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ is the lightest supersymmetric particle (LSP); see ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ Mass Limits. It is not possible to quote rigorous mass limits because they are extremely model dependent; i.e. they depend on branching ratios of various ${{\widetilde{\mathit \chi}}^{0}}$ decay modes, on the masses of decay products (${{\widetilde{\mathit e}}}$, ${{\widetilde{\mathit \gamma}}}$, ${{\widetilde{\mathit q}}}$, ${{\widetilde{\mathit g}}}$), and on the ${{\widetilde{\mathit e}}}$ mass exchanged in ${{\mathit e}^{+}}$ ${{\mathit e}^{-}}$ $\rightarrow$ ${{\widetilde{\mathit \chi}}_{{i}}^{0}}{{\widetilde{\mathit \chi}}_{{j}}^{0}}$ . Limits arise either from direct searches, or from the MSSM constraints set on the gaugino and higgsino mass parameters $\mathit M_{2}$ and $\mu $ through searches for lighter charginos and neutralinos. Often limits are given as contour plots in the ${\mathit m}_{{{\widetilde{\mathit \chi}}^{0}}}–{\mathit m}_{{{\widetilde{\mathit e}}}}$ plane vs other parameters. When specific assumptions are made, e.g, the neutralino is a pure photino (${{\widetilde{\mathit \gamma}}}$), pure z-ino (${{\widetilde{\mathit Z}}}$), or pure neutral higgsino (${{\widetilde{\mathit H}}^{0}}$), the neutralinos will be labelled as such.

Limits obtained from ${{\mathit e}^{+}}{{\mathit e}^{-}}$ collisions at energies up to 136 GeV, as well as other limits from different techniques, are now superseded and have not been included in this compilation. They can be found in the 1998 Edition (The European Physical Journal C3 1 (1998)) of this Review. Some later papers are now obsolete and have been omitted. They were last listed in our PDG 2014 edition: K. Olive, $\mathit et~al.$ (Particle Data Group), Chinese Physics C38 070001 (2014) (http://pdg.lbl.gov).

VALUE (GeV) CL% DOCUMENT ID TECN  COMMENT $> 275$ 95 1 TUMASYAN 2022 Q CMS 2 or 3 ${{\mathit \ell}}$ (soft), $\not E_T$; Tchi1n2F, wino-bino,${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}−{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$=10 GeV $> 205$ 95 1 TUMASYAN 2022 Q CMS 2 or 3 ${{\mathit \ell}}$ (soft), $\not E_T$; higgsino model with ${{\widetilde{\mathit \chi}}_{{2}}^{0}}{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ and ${{\widetilde{\mathit \chi}}_{{2}}^{0}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ prod., ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}−{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 7.5 GeV $> 150$ 95 1 TUMASYAN 2022 Q CMS 2 or 3 ${{\mathit \ell}}$ (soft), $\not E_T$; higgsino model with ${{\widetilde{\mathit \chi}}_{{2}}^{0}}{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ and ${{\widetilde{\mathit \chi}}_{{2}}^{0}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ prod., ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}−{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 3 GeV $> 1450$ 95 2 TUMASYAN 2022 S CMS 2 same-sign ${{\mathit e}}$ or ${{\mathit \mu}}$, 3 or 4 leptons, Tchi1n2B (flavor-democratic), ${\mathit m}_{{{\widetilde{\mathit \ell}}}}$ = 1/2(${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}+{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$), ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 850 GeV $> 1360$ 95 2 TUMASYAN 2022 S CMS 2 same-sign ${{\mathit e}}$ or ${{\mathit \mu}}$, 3 or 4 leptons, Tchi1n2B (flavor-democratic), ${\mathit m}_{{{\widetilde{\mathit \ell}}}}$ = 1/2(${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}+{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$), ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 1290$ 95 2 TUMASYAN 2022 S CMS 2 same-sign ${{\mathit e}}$ or ${{\mathit \mu}}$, 3 or 4 leptons, Tchi1n2B (flavor-democratic), ${\mathit m}_{{{\widetilde{\mathit \ell}}}}$ = 0.05${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}+0.95{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 1440$ 95 2 TUMASYAN 2022 S CMS 2 same-sign ${{\mathit e}}$ or ${{\mathit \mu}}$, 3 or 4 leptons, Tchi1n2B (flavor-democratic), ${\mathit m}_{{{\widetilde{\mathit \ell}}}}$ = 0.95${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}+0.05{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 1140$ 95 2 TUMASYAN 2022 S CMS 2 same-sign ${{\mathit e}}$ or ${{\mathit \mu}}$, 3 or 4 leptons, Tchi1n2B (lepton in ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ decay is ${{\mathit \tau}}$), ${\mathit m}_{{{\widetilde{\mathit \ell}}}}$ = 1/2(${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}+{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$), ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 1110$ 95 2 TUMASYAN 2022 S CMS 2 same-sign ${{\mathit e}}$ or ${{\mathit \mu}}$, 3 or 4 leptons, Tchi1n2B (lepton in ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ decay is ${{\mathit \tau}}$), ${\mathit m}_{{{\widetilde{\mathit \ell}}}}$ = 0.05${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}+0.95{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 1140$ 95 2 TUMASYAN 2022 S CMS 2 same-sign ${{\mathit e}}$ or ${{\mathit \mu}}$, 3 or 4 leptons, Tchi1n2B (lepton in ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ decay is ${{\mathit \tau}}$), ${\mathit m}_{{{\widetilde{\mathit \ell}}}}$ = 0.95${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}+0.05{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 980$ 95 2 TUMASYAN 2022 S CMS 2 same-sign ${{\mathit e}}$ or ${{\mathit \mu}}$, 3 or 4 leptons, Tchi1n2B (leptons in ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ and ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ decays are ${{\mathit \tau}}$), ${\mathit m}_{{{\widetilde{\mathit \ell}}}}$ = 1/2(${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}+{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$), ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 905$ 95 2 TUMASYAN 2022 S CMS 2 same-sign ${{\mathit e}}$ or ${{\mathit \mu}}$, 3 or 4 leptons, Tchi1n2B (leptons in ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ and ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ decays are ${{\mathit \tau}}$), ${\mathit m}_{{{\widetilde{\mathit \ell}}}}$ = 0.05${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}+0.95{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 875$ 95 2 TUMASYAN 2022 S CMS 2 same-sign ${{\mathit e}}$ or ${{\mathit \mu}}$, 3 or 4 leptons, Tchi1n2B (leptons in ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ and ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ decays are ${{\mathit \tau}}$), ${\mathit m}_{{{\widetilde{\mathit \ell}}}}$ = 0.95${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}+0.05{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 650$ 95 2 TUMASYAN 2022 S CMS 2 same-sign ${{\mathit e}}$ or ${{\mathit \mu}}$, 3 or 4 leptons, Tchi1n2F, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 260$ 95 2 TUMASYAN 2022 S CMS 2 same-sign ${{\mathit e}}$ or ${{\mathit \mu}}$, 3 or 4 leptons, Tchi1n2E, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $\text{none 265 - 305}$ 95 3 TUMASYAN 2022 V CMS 3, 4 ${{\mathit b}}$-tagged or 2 large-radius jets, $\not E_T$; higgsino ${{\widetilde{\mathit \chi}}_{{2}}^{0}}{{\widetilde{\mathit \chi}}_{{3}}^{0}}$ prod. with ${{\widetilde{\mathit \chi}}_{{2,3}}^{0}}$ $\rightarrow$ ${{\mathit H}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ ; ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 1 GeV $> 640$ 95 4 AAD 2021 BG ATLS 3${{\mathit \ell}}$+ $\not E_T$, Tchi1n2F, wino cross section, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 300$ 95 4 AAD 2021 BG ATLS 3${{\mathit \ell}}$+ $\not E_T$, Tchi1n2F, wino cross section, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ $−$ ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = ${\mathit m}_{{{\mathit Z}}}$ $>240$ 95 4 AAD 2021 BG ATLS 3${{\mathit \ell}}$+ $\not E_T$, Tchi1n2F, wino cross section, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}−{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$= 10 GeV $> 195$ 95 4 AAD 2021 BG ATLS 3${{\mathit \ell}}$+ $\not E_T$, Tchi1n2Ga, higgsino cross section, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}−{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$= 10 GeV $>190$ 95 4 AAD 2021 BG ATLS 3${{\mathit \ell}}$+ $\not E_T$, Tchi1n2E, wino cross section, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 1600$ 95 5 AAD 2021 Y ATLS ${}\geq{}4{{\mathit \ell}}$, RPV Tchi1n2I with ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{\pm}}{{\mathit \ell}^{\mp}}{{\mathit \nu}}$ , ${{\mathit \lambda}_{{12k}}}{}\not=$ 0, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 1200 GeV $> 1100$ 95 5 AAD 2021 Y ATLS ${}\geq{}4{{\mathit \ell}}$, RPV Tchi1n2I with ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{\pm}}{{\mathit \ell}^{\mp}}{{\mathit \nu}}$ , ${{\mathit \lambda}_{{i33}}}{}\not=$ 0, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 1000 GeV $\bf{> 750}$ 95 6 SIRUNYAN 2021 M CMS ${{\mathit \ell}^{\pm}}{{\mathit \ell}^{\mp}}$ + $\not E_T$, Tchi1n2Fa , ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ $<$ 100 GeV $\text{none 400 - 820}$ 95 7 TUMASYAN 2021 C CMS 1 ${{\mathit \ell}^{\pm}}$ + 2${{\mathit b}}$-jets + $\not E_T$, Tchi1n2E, ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ = 200 GeV $\text{none 160 - 820}$ 95 7 TUMASYAN 2021 C CMS 1 ${{\mathit \ell}^{\pm}}$ + 2${{\mathit b}}$-jets + $\not E_T$, Tchi1n2E, ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ = 0 GeV $> 380$ 95 8 AAD 2020 AN ATLS 2${{\mathit \gamma}}$ + $\not E_T$,Tn1n1A, GMSB $> 193$ 95 9 AAD 2020 I ATLS 2${{\mathit \ell}}$ (soft), jets, $\not E_T$; Tchi1n2Ga, higgsino, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}−{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$=9.3 GeV $> 240$ 95 10 AAD 2020 I ATLS 2${{\mathit \ell}}$ (soft), jets, $\not E_T$; Tchi1n2Fa, wino, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ $−$ ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 7 GeV $> 345$ 95 11 AAD 2020 K ATLS 3${{\mathit \ell}}+\not E_T$, Tchi1n2F, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 740$ 95 12 AAD 2020 R ATLS 1${{\mathit \ell}}$ + 2${{\mathit b}}$-jets + $\not E_T$, Tchi1n2E, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 290$ 95 13 SIRUNYAN 2020 AU CMS soft ${{\mathit \tau}}$ + jet + $\not E_T$, Tchi1n2D, wino, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}$ $−$ ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 50 GeV $> 680$ 95 14 AABOUD 2019 AU ATL 0, 1, 2 or more ${{\mathit \ell}}$, ${{\mathit H}}$ ( $\rightarrow$ ${{\mathit \gamma}}{{\mathit \gamma}}$ , ${{\mathit b}}{{\mathit b}}$ , ${{\mathit W}}{{\mathit W}^{*}}$ , ${{\mathit Z}}{{\mathit Z}^{*}}$ , ${{\mathit \tau}}{{\mathit \tau}}$ ) (various searches), Tchi1n2E, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$=0 GeV $>112$ 95 15 SIRUNYAN 2019 BU CMS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\widetilde{\mathit \chi}}_{{1}}^{+}}{{\widetilde{\mathit \chi}}_{{2}}^{0}}$ + 2 jets, ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ , heavy sleptons, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ $−$ ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 1 GeV, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ = ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{+}}}$ $>215$ 95 15 SIRUNYAN 2019 BU CMS ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\widetilde{\mathit \chi}}_{{1}}^{+}}{{\widetilde{\mathit \chi}}_{{2}}^{0}}$ + 2 jets, ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{+}}{{\mathit \ell}^{-}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ , heavy sleptons, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ $−$ ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 30 GeV, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ = ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{+}}}$ $> 760$ 95 16 AABOUD 2018 AY ATLS 2${{\mathit \tau}}+\not E_T$, Tchi1n2D and ${{\widetilde{\mathit \tau}}_{{L}}}$-only, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 1125$ 95 17 AABOUD 2018 BT ATLS 2,3${{\mathit \ell}}+\not E_T$, Tchi1n2C, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$=0 GeV $> 580$ 95 18 AABOUD 2018 BT ATLS 2,3${{\mathit \ell}}+\not E_T$, Tchi1n2F, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$=0 GeV $\text{none 130 - 230, 290 - 880}$ 95 19 AABOUD 2018 CK ATLS 2${{\mathit H}}$ ( $\rightarrow$ ${{\mathit b}}{{\mathit b}}$ )+$\not E_T$,Tn1n1A, GMSB $\text{none 220 - 600}$ 95 20 AABOUD 2018 CO ATLS 2,3${{\mathit \ell}}$ + $\not E_T$, recursive jigsaw, Tchi1n2F, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 145$ 95 21 AABOUD 2018 R ATLS 2${{\mathit \ell}}$ (soft) + $\not E_T$, Tchi1n2G, higgsino, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ $−$ ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 5 GeV $> 175$ 95 22 AABOUD 2018 R ATLS 2${{\mathit \ell}}$ (soft) + $\not E_T$, Tchi1n2F, wino, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ $−$ ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 10 GeV $> 1060$ 95 23 AABOUD 2018 U ATLS 2 ${{\mathit \gamma}}$ + $\not E_T$, GGM,Tchi1chi1A, any NLSP mass $> 167$ 95 24 SIRUNYAN 2018 AJ CMS 2${{\mathit \ell}}$ (soft) + $\not E_T$, Tchi1n2G, higgsino, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ $−$ ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 15 GeV $> 710$ 95 25 SIRUNYAN 2018 DP CMS 2${{\mathit \tau}}+\not E_T$, Tchi1n2D, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $\text{none 220 - 490}$ 95 26 SIRUNYAN 2017 AW CMS 1${{\mathit \ell}}$+ 2 ${{\mathit b}}$-jets + $\not E_T$, Tchi1n2E, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $>600$ 95 27 AAD 2016 AA ATLS 3,4${{\mathit \ell}}$ + $\not E_T$, Tn2n3A, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$=0GeV $>670$ 95 27 AAD 2016 AA ATLS 3,4${{\mathit \ell}}+\not E_T$,Tn2n3B,${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}<$ 200GeV $>250$ 95 28 AAD 2015 BA ATLS ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}$ = ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 380$ 95 29 AAD 2014 H ATLS ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit \tau}^{\pm}}{{\mathit \nu}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}{{\mathit \tau}^{\pm}}{{\mathit \tau}^{\mp}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ , simplified model, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}$ = ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 700$ 95 29 AAD 2014 H ATLS ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{\pm}}{{\mathit \nu}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}{{\mathit \ell}^{\pm}}{{\mathit \ell}^{\mp}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ , simplified model, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}$ = ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 345$ 95 29 AAD 2014 H ATLS ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit W}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}{{\mathit Z}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ , simplified model, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}$ = ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 148$ 95 29 AAD 2014 H ATLS ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit W}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}{{\mathit H}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ , simplified model, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}$ = ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV $> 620$ 95 30 AAD 2014 X ATLS ${}\geq{}4{{\mathit \ell}^{\pm}}$, ${{\widetilde{\mathit \chi}}_{{2,3}}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{\pm}}{{\mathit \ell}^{\mp}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ , ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV 31 AAD 2013 ATLS 3${{\mathit \ell}^{\pm}}$ + $\not E_T$, pMSSM, SMS 32 CHATRCHYAN 2012 BJ CMS ${}\geq{}$2 ${{\mathit \ell}}$, jets + $\not E_T$, ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}{{\widetilde{\mathit \chi}}_{{2}}^{0}}$ $\bf{> 62.4}$ 95 33 ABREU 2000 W DLPH ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$, 1${}\leq{}$tan $\beta {}\leq{}$40, all $\Delta \mathit m$, all $\mathit m_{0}$ $\bf{> 99.9}$ 95 33 ABREU 2000 W DLPH ${{\widetilde{\mathit \chi}}_{{3}}^{0}}$, 1${}\leq{}$tan $\beta {}\leq{}$40, all $\Delta \mathit m$, all $\mathit m_{0}$ $\bf{> 116.0}$ 95 33 ABREU 2000 W DLPH ${{\widetilde{\mathit \chi}}_{{4}}^{0}}$, 1${}\leq{}$tan $\beta {}\leq{}$40, all $\Delta \mathit m$, all $\mathit m_{0}$ • • We do not use the following data for averages, fits, limits, etc. • • $> 310$ 95 34 AAD 2020 AN ATLS 2${{\mathit \gamma}}$ + $\not E_T$, Tchi1n2E, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$=0 GeV $\text{none 180 - 355}$ 95 35 AAD 2014 G ATLS ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit W}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}{{\mathit Z}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ , simplified model, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}$ = ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$, ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 0 GeV 36 KHACHATRYAN 2014 I CMS ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ $\rightarrow$ ( ${{\mathit Z}}$ , ${{\mathit H}}$) ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ ${{\widetilde{\mathit \ell}}}{{\mathit \ell}}$ , simplified model 37 AAD 2012 AS ATLS 3${{\mathit \ell}^{\pm}}$ + $\not E_T$, pMSSM 38 AAD 2012 T ATLS ${{\mathit \ell}^{\pm}}{{\mathit \ell}^{\pm}}$ + $\not E_T$, ${{\mathit p}}$ ${{\mathit p}}$ $\rightarrow$ ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}{{\widetilde{\mathit \chi}}_{{2}}^{0}}$ 1  TUMASYAN 2022Q searched in up to 137 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for evidence of electroweakino and top squark pair production with a small mass difference between the produced supersymmetric particles and the lightest neutralino in events with two or three low-momentum leptons and missing transverse momentum. No significant excess above the Standard Model expectations is observed. Limits are set on the mass of ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ in the model Tchi1n2F, see their Figure 8. Limits are also set in a higgsino simplified model with both ${{\widetilde{\mathit \chi}}_{{2}}^{0}}{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ and ${{\widetilde{\mathit \chi}}_{{2}}^{0}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ production, where ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit Z}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ and ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}$ = 1/2(${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}+{\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$). A model inspired by the pMSSM is used for further interpretations in the case of a higgsino LSP, see their Figure 9. Limits are also set on the mass of the top squark in the models Tstop2 and Tstop3, see their Figure 10. 2  TUMASYAN 2022S searched in 137 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for evidence of electroweakino pair production in events with three or four leptons, with up to two hadronically decaying ${{\mathit \tau}}$ leptons, or two same-sign light leptons (${{\mathit e}}$ or ${{\mathit \mu}}$). No significant excess above the Standard Model expectations is observed. Limits are set on the mass of ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ in the models Tchi1n2B (in flavory-democratic and tau-enriched or -dominated scenarios), Tchi1n2E, Tchi1n2F, see their Figures $16 - 20$, and on the mass of the higgsino-triplet ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$, ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$, and ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ in the models Tn1n1A, Tn1n1B, and Tn1n1C, see their Figure 21. 3  TUMASYAN 2022V searched in 137 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for evidence of electroweakino pair production with decay to two Higgs bosons ${{\mathit H}}$, with ${{\mathit H}}$ $\rightarrow$ ${{\mathit b}}{{\overline{\mathit b}}}$ , resulting either in 4 resolved ${{\mathit b}}$-jets or two large-radius jets, and large $\not E_T$. No significant excess above the Standard Model expectations is observed. Limits are set on the mass of ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ in the models Tn1n1A, see their Figures 11 and 12, or in a model where higgsino-like nearly mass degenerate ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{3}}^{0}}$ are pair produced and each decay to ${{\mathit H}}$ and a bino-like ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$, see their Figure 13. Limits are also set on the gluino mass in the model Tglu1I, see their Figure 14. 4  AAD 2021BG searched in 139 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for pair production ${{\widetilde{\mathit \chi}}_{{2}}^{0}}{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ in final states with three leptons, with and without assuming the presence of a ${{\mathit Z}}$ $\rightarrow$ ${{\mathit \ell}}{{\mathit \ell}}$ decay. No significant excess above the Standard Model predictions is observed. Limits are set on the ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ mass in Tchi1n2E, Tchi1n2F and Tchi1n2Ga. See their Fig. 16. 5  AAD 2021Y searched in 139 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for supersymmetry in events with four or more leptons (electrons, muons and tau-leptons). No significant excess above the Standard Model expectations is observed. Limits are set on Tchi1n12-GGM, and RPV models similar to Tchi1n2I, Tglu1A (with ${{\mathit q}}$ = ${{\mathit u}}$, ${{\mathit d}}$, ${{\mathit s}}$, ${{\mathit c}}$, ${{\mathit b}}$, with equal branching fractions), and ${{\widetilde{\mathit \ell}}_{{L}}}$ $/$ ${{\widetilde{\mathit \nu}}}$ $\rightarrow$ ${{\mathit \ell}}$ $/$ ${{\mathit \nu}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ (mass-degenerate ${{\widetilde{\mathit \ell}}_{{L}}}$ and ${{\widetilde{\mathit \nu}}}$ of all 3 generations), all with ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{\pm}}{{\mathit \ell}^{\mp}}{{\mathit \nu}}$ via ${{\mathit \lambda}_{{12k}}}$ or ${{\mathit \lambda}_{{i 33}}}$ (where $\mathit i,k$ $\in$ 1,2), see their Figure 11. 6  SIRUNYAN 2021M searched in 137 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for supersymmetry in events with two opposite-sign same-flavor leptons (electrons, muons) and $\not E_T$. No significant excess above the Standard Model expectations is observed. Limits are set on the gluino mass in the simplified model Tglu4C, see their Figure 10, on the ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ mass in Tchi1n2Fa, see their Figure 11, on the ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ mass in Tn1n1C and Tn1n1B for ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}={\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}={\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$, see their Figure 12. Limits are also set on the light squark mass for the simplified model Tsqk2A, on the sbottom mass in Tsbot3, see their Figure 13, and on the slepton mass in direct electroweak pair production of mass-degenerate left- and right-handed sleptons (selectrons and smuons), see their Figure 14. 7  TUMASYAN 2021C searched in 137 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for supersymmetry in events with with one lepton, a Higgs boson decaying to a pair of bottom quarks, and large $\not E_T$. No significant excess above the Standard Model expectations is observed. Lower limits are set on the masses of ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ in the simplified model Tchi1n2E, see their Figure 6. 8  AAD 2020AN searched in 139 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for events with two photons and missing transverse momentum. Events are further categorised in terms of lepton or jet multiplicity. No significant excess over the expected background is observed. Limits at 95$\%$ C.L. are set on the Higgsino mass in the T1n1n1A simplified model, see their Figure 11. 9  AAD 2020I reported on ATLAS searches for electroweak production in models with compressed mass spectra as Tchi1n2Ga. A dataset of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV corresponding to an integrated luminosity of 139 ${\mathrm {fb}}{}^{-1}$ was used. Events with $\not E_T$, two same-flavour, opposite-charge, low-transverse-momentum leptons, and jets from initial-state radiation or characteristic of vector-boson fusion production are selected. Constraints at 95$\%$ C.L. are placed in Higgsino models on the mass of the ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ (the ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ mass is halfway between the ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ masses) at 193 GeV for a mass splitting between ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ of 9.3 GeV and extend down to a mass splitting of 2.4 GeV at the LEP chargino mass limit. See their Fig. 14(a). 10  AAD 2020I reported on ATLAS searches for electroweak production in models with compressed mass spectra as Tchi1n2Fa. A dataset of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV corresponding to an integrated luminosity of 139 ${\mathrm {fb}}{}^{-1}$ was used. Events with $\not E_T$, two same-flavour, opposite-charge, low-transverse-momentum leptons, and jets from initial-state radiation or characteristic of vector-boson fusion production are selected. Constraints at 95$\%$ C.L. are placed in Wino-Bino models on the mass of the ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ (degenerate with ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$) at 240 GeV for a mass splitting between ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ of 7 GeV and extend down to a mass splitting of 1.5 GeV at the LEP chargino mass limit of 92.4 GeV. See their Fig. 14(b,c). 11  AAD 2020K reported on a search for electroweak production in models with mass splittings near the electroweak scale as Tchi1n2F and exploiting three-lepton final state events with an emulated recursive jigsaw reconstruction method. The analysis uses a dataset of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV corresponding to an integrated luminosity of 139 ${\mathrm {fb}}{}^{-1}$. Exclusion limits at 95$\%$ C.L. are derived on next-to-lightest neutralinos and charginos with masses up to 345 GeV for a massless lightest neutralino, see their Fig. 7. 12  AAD 2020R searched for electroweak production in the model Tchi1n2E, selecting events with a pair of ${{\mathit b}}$-tagged jets consistent with those from a Higgs boson decay, either an electron or a muon from the ${{\mathit W}}$ boson decay and $\not E_T$. The analysis uses a dataset of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV corresponding to an integrated luminosity of 139 ${\mathrm {fb}}{}^{-1}$. Exclusion limits at 95$\%$ C.L. are derived on next-to-lightest neutralinos and charginos with masses up to 740 GeV for a massless lightest neutralino, assuming pure wino cross-sections. See their Fig. 6. 13  SIRUNYAN 2020AU searched in 77.2 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for events containing one soft, hadronically decaying tau lepton, one energetic jet from initial-state radiation, and large $\not E_T$. No excess over the expected background is observed. Limits are derived on the wino mass in the Tchi1n2D simplified model, see their Figure 2. 14  AABOUD 2019AU searched in 36.1 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for direct electroweak production of charginos and next-to-lightest neutralinos decaying into lightest neutralinos and a ${{\mathit W}}$ and a Higgs boson, respectively. Fully hadronic, semileptonic, diphoton, and multilepton (electrons, muons) final states with missing transverse momentum are considered in this search. Observations are consistent with the Standard Model expectations, and 95$\%$ confidence-level limits of up to 680 GeV on the chargino/next-to-lightest neutralino masses are set (Tchi1n2E model). See their Figure 14 for an overlay of exclusion contours from all searches. 15  SIRUNYAN 2019BU searched for pair production of gauginos via vector boson fusion assuming the gaugino spectrum is compressed, in 35.9 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV. The final states explored included zero leptons plus two jets, one lepton plus two jets, and one hadronic tau plus two jets. A similar bound is obtained in the light slepton limit. 16  AABOUD 2018AY searched in 36.1 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for direct electroweak production of charginos and neutralinos as in Tchi1n2D models, in events characterised by the presence of at least two hadronically decaying tau leptons and large missing transverse energy. No significant deviation from the expected SM background is observed. Assuming decays via intermediate ${{\widetilde{\mathit \tau}}_{{L}}}$ and ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{\pm}}}$ = ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$, the observed limits rule out ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ masses up to 760 GeV for a massless ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$. See their Fig.7 (right). Interpretations are also provided in Fig 8 (bottom) for different assumptions on the ratio between ${\mathit m}_{{{\widetilde{\mathit \tau}}}}$ and ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ + ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$. 17  AABOUD 2018BT searched in 36.1 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for direct electroweak production of charginos, chargino and next-to-lightest neutralinos and sleptons in events with two or three leptons (electrons or muons), with or without jets, and large missing transverse energy. No significant excess above the Standard Model expectations is observed. Limits are set on the next-to-lightest neutralino mass up to 1100 GeV for massless ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ in the Tchi1n2C simplified model exploiting the 3${{\mathit \ell}}$ signature, see their Figure 8(c). 18  AABOUD 2018BT searched in 36.1 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for direct electroweak production of charginos, chargino and next-to-lightest neutralinos and sleptons in events with two or three leptons (electrons or muons), with or without jets, and large missing transverse energy. No significant excess above the Standard Model expectations is observed. Limits are set on the next-to-lightest neutralino mass up to 580 GeV for massless ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ in the Tchi1n2F simplified model exploiting the 2${{\mathit \ell}}$+2 jets and 3${{\mathit \ell}}$ signatures, see their Figure 8(d). 19  AABOUD 2018CK searched for events with at least 3 ${{\mathit b}}$-jets and large missing transverse energy in two datasets of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV of 36.1 ${\mathrm {fb}}{}^{-1}$ and 24.3 ${\mathrm {fb}}{}^{-1}$ depending on the trigger requirements. The analyses aimed to reconstruct two Higgs bosons decaying to pairs of ${{\mathit b}}$-quarks. No significant excess above the Standard Model expectations is observed. Limits are set on the Higgsino mass in the T1n1n1A simplified model, see their Figure 15(a). Constraints are also presented as a function of the BR of Higgsino decaying into an higgs boson and a gravitino, see their Figure 15(b). 20  AABOUD 2018CO searched in 36.1 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for direct electroweak production of mass-degenerate charginos and next-to-lightest neutralinos in events with two or three leptons (electrons or muons), with or without jets, and large missing transverse energy. The search channels are based on recursive jigsaw reconstruction. Limits are set on the next-to-lightest neutralinos mass up to 600 GeV for massless neutralinos in the Tchi1n2F simplified model exploiting the statistical combination of 2${{\mathit \ell}}$+2 jets and 3${{\mathit \ell}}$ channels. Next-to-lightest neutralinos masses below 220 GeV are not excluded due to an excess of events above the SM prediction in the dedicated regions. See their Figure 13(d). 21  AABOUD 2018R searched in 36.1 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for electroweak production in scenarios with compressed mass spectra in final states with two low-momentum leptons and missing transverse momentum. The data are found to be consistent with the SM prediction. Results are interpreted in Tchi1n2G higgsino models, and ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ masses are excluded up to 145 GeV for ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ $−$ ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 5 GeV. The exclusion limits extend down to mass splittings of 2.5 GeV, see their Fig. 10 (top). Results are also interpreted in terms of exclusion bounds on the production cross-sections for the NUHM2 scenario as a function of the universal gaugino mass ${\mathit m}_{\mathrm {1/2}}$ and ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ $−$ ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$, see their Fig. 12. 22  AABOUD 2018R searched in 36.1 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for electroweak production in scenarios with compressed mass spectra in final states with two low-momentum leptons and missing transverse momentum. The data are found to be consistent with the SM prediction. Results are interpreted in Tchi1n2F wino models, and ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ masses are excluded up to 175 GeV for ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ $−$ ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$ = 10 GeV. The exclusion limits extend down to mass splittings of 2 GeV, see their Fig. 10 (bottom). Results are also interpreted in terms of exclusion bounds on the production cross-sections for the NUHM2 scenario as a function of the universal gaugino mass ${\mathit m}_{\mathrm {1/2}}$ and ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{2}}^{0}}}$ $−$ ${\mathit m}_{{{\widetilde{\mathit \chi}}_{{1}}^{0}}}$, see their Fig. 12. 23  AABOUD 2018U searched in 36.1 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV in events with at least one isolated photon, possibly jets and significant transverse momentum targeting generalised models of gauge-mediated SUSY breaking. No significant excess of events is observed above the SM prediction. Results of the diphoton channel are interpreted in terms of lower limits on the masses of gauginos Tchi1chi1A models, which reach as high as 1.3 TeV. Gaugino masses below 1060 GeV are excluded for any NLSP mass, see their Fig. 10. 24  SIRUNYAN 2018AJ searched in 35.9 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for events containing two low-momentum, oppositely charged leptons (electrons or muons) and $\not E_T$. No excess over the expected background is observed. Limits are derived on the wino mass in the Tchi1n2F simplified model, see their Figure 5. Limits are also set on the stop mass in the Tstop10 simplified model, see their Figure 6. Finally, limits are set on the Higgsino mass in the Tchi1n2G simplified model, see Figure 8 and in the pMSSM, see Figure 7. 25  SIRUNYAN 2018DP searched in 35.9 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for direct electroweak production of charginos and neutralinos or of chargino pairs in events with a tau lepton pair and significant missing transverse momentum. Both hadronic and leptonic decay modes are considered for the tau lepton. No significant excess above the Standard Model expectations is observed. Limits are set on the chargino mass in the Tchi1chi1D and Tchi1n2 simplified models, see their Figures 14 and 15. Also, excluded stau pair production cross sections are shown in Figures 11, 12, and 13. 26  SIRUNYAN 2017AW searched in 35.9 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for events with a charged lepton (electron or muon), two jets identified as originating from a ${{\mathit b}}$-quark, and large $\not E_T$. No significant excess above the Standard Model expectations is observed. Limits are set on the mass of the chargino and the next-to-lightest neutralino in the Tchi1n2E simplified model, see their Figure 6. 27  AAD 2016AA summarized and extended ATLAS searches for electroweak supersymmetry in final states containing several charged leptons, $\not E_T$, with or without hadronic jets, in 20 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV. The paper reports the results of new interpretations and statistical combinations of previously published analyses, as well as new analyses. Exclusion limits at 95$\%$ C.L. are set on mass-degenerate ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{3}}^{0}}$ masses in the Tn2n3A and Tn2n3B simplified models. See their Fig. 15. 28  AAD 2015BA searched in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV for electroweak production of charginos and neutralinos decaying to a final state containing a ${{\mathit W}}$ boson and a 125 GeV Higgs boson, plus missing transverse momentum. No excess beyond the Standard Model expectation is observed. Exclusion limits are derived in simplified models of direct chargino and next-to-lightest neutralino production, with the decays ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ $\rightarrow$ ${{\mathit W}^{\pm}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ and ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ $\rightarrow$ ${{\mathit H}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ having 100$\%$ branching fraction, see Fig. 8. A combination of the multiple final states for the Higgs decay yields the best limits (Fig. 8d). 29  AAD 2014H searched in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV for electroweak production of charginos and neutralinos decaying to a final sate with three leptons and missing transverse momentum. No excess beyond the Standard Model expectation is observed. Exclusion limits are derived in simplified models of direct chargino and next-to-lightest neutralino production, with decays to the lightest neutralino via either all three generations of leptons, staus only, gauge bosons, or Higgs bosons, see Fig. 7. An interpretation in the pMSSM is also given, see Fig. 8. 30  AAD 2014X searched in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV for events with at least four leptons (electrons, muons, taus) in the final state. No significant excess above the Standard Model expectations is observed. Limits are set on the neutralino mass in an R-parity conserving simplified model where the decay ${{\widetilde{\mathit \chi}}_{{2,3}}^{0}}$ $\rightarrow$ ${{\mathit \ell}^{\pm}}{{\mathit \ell}^{\mp}}{{\widetilde{\mathit \chi}}_{{1}}^{0}}$ takes place with a branching ratio of 100$\%$, see Fig. 10. 31  AAD 2013 searched in 4.7 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV for charginos and neutralinos decaying to a final state with three leptons (${{\mathit e}}$ and ${{\mathit \mu}}$) and missing transverse energy. No excess beyond the Standard Model expectation is observed. Exclusion limits are derived in the phenomenological MSSM, see Fig. 2 and 3, and in simplified models, see Fig. 4. For the simplified models with intermediate slepton decays, degenerate ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}$ and ${{\widetilde{\mathit \chi}}_{{2}}^{0}}$ masses up to 500 GeV are excluded at 95$\%$ C.L. for very large mass differences with the ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$. Supersedes AAD 2012AS. 32  CHATRCHYAN 2012BJ searched in 4.98 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV for direct electroweak production of charginos and neutralinos in events with at least two leptons, jets and missing transverse momentum. No significant excesses over the expected SM backgrounds are observed and 95$\%$ C.L. limits on the production cross section of ${{\widetilde{\mathit \chi}}_{{1}}^{\pm}}{{\widetilde{\mathit \chi}}_{{2}}^{0}}$ pair production were set in a number of simplified models, see Figs. 7 to 12. Most limits are for exactly 3 jets. 33  ABREU 2000W combines data collected at $\sqrt {\mathit s }$=189 GeV with results from lower energies. The mass limit is obtained by constraining the MSSM parameter space with gaugino and sfermion mass universality at the GUT scale, using the results of negative direct searches for neutralinos (including cascade decays and ${{\widetilde{\mathit \tau}}}{{\mathit \tau}}$ final states) from ABREU 2001 , for charginos from ABREU 2000J and ABREU 2000T (for all $\Delta \mathit m_{+}$), and for charged sleptons from ABREU 2001B. The results hold for the full parameter space defined by all values of $\mathit M_{2}$ and $\vert \mu \vert {}\leq{}$2 TeV with the ${{\widetilde{\mathit \chi}}_{{1}}^{0}}$ as LSP. 34  AAD 2020AN searched in 139 ${\mathrm {fb}}{}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 13 TeV for events with two photons and missing transverse momentum. Events are further categorised in terms of lepton or jet multiplicity. No significant excess over the expected background is observed. Limits at 95$\%$ C.L. are derived in Tchi1n2E simplified models. Next-to-lightest neutralinos and charginos with masses up to 310 GeV for a massless lightest neutralino are excluded. See their Fig. 10. 35  AAD 2014G searched in 20.3 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV for electroweak production of chargino-neutralino pairs, decaying to a final sate with two leptons (${{\mathit e}}$ and ${{\mathit \mu}}$) and missing transverse momentum. No excess beyond the Standard Model expectation is observed. Exclusion limits are derived in simplified models of chargino and next-to-lightest neutralino production, with decays to the lightest neutralino via gauge bosons, see Fig. 7. An interpretation in the pMSSM is also given, see Fig. 10. 36  KHACHATRYAN 2014I searched in 19.5 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 8 TeV for electroweak production of charginos and neutralinos decaying to a final state with three leptons (${{\mathit e}}$ or ${{\mathit \mu}}$) and missing transverse momentum, or with a ${{\mathit Z}}$-boson, dijets and missing transverse momentum. No excess beyond the Standard Model expectation is observed. Exclusion limits are derived in simplified models, see Figs. $12 - 16$. 37  AAD 2012AS searched in 2.06 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV for charginos and neutralinos decaying to a final state with three leptons (${{\mathit e}}$ and ${{\mathit \mu}}$) and missing transverse energy. No excess beyond the Standard Model expectation is observed. Exclusion limits are derived in the phenomenological MSSM, see Fig. 2 (top), and in simplified models, see Fig. 2 (bottom). 38  AAD 2012T looked in 1 fb${}^{-1}$ of ${{\mathit p}}{{\mathit p}}$ collisions at $\sqrt {s }$ = 7 TeV for the production of supersymmetric particles decaying into final states with missing transverse momentum and exactly two isolated leptons (${{\mathit e}}$ or ${{\mathit \mu}}$). Same-sign dilepton events were separately studied. Additionally, in opposite-sign events, a search was made for an excess of same-flavor over different-flavor lepton pairs. No excess over the expected background is observed and limits are placed on the effective production cross section of opposite-sign dilepton events with $\not E_T$ $>$ 250 GeV and on same-sign dilepton events with $\not E_T$ $>$ 100 GeV. The latter limit is interpreted in a simplified electroweak gaugino production model.

References:

TUMASYAN 2022Q JHEP 2204 091 Search for supersymmetry in final states with two or three soft leptons and missing transverse momentum in proton-proton collisions at $ \sqrt{s} $ = 13 TeV TUMASYAN 2022S JHEP 2204 147 Search for electroweak production of charginos and neutralinos in proton-proton collisions at $ \sqrt{s} $ = 13 TeV TUMASYAN 2022V JHEP 2205 014 Search for higgsinos decaying to two Higgs bosons and missing transverse momentum in proton-proton collisions at $ \sqrt{s} $ = 13 TeV AAD 2021Y JHEP 2107 167 Search for supersymmetry in events with four or more charged leptons in 139 fb$^{?1}$ of $ \sqrt{s} $ = 13 TeV pp collisions with the ATLAS detector AAD 2021BG EPJ C81 1118 Search for chargino?neutralino pair production in final states with three leptons and missing transverse momentum in $\sqrt{s} = 13$ TeV pp collisions with the ATLAS detector SIRUNYAN 2021M JHEP 2104 123 Search for supersymmetry in final states with two oppositely charged same-flavor leptons and missing transverse momentum in proton-proton collisions at $\sqrt{s} =$ 13 TeV TUMASYAN 2021C JHEP 2110 045 Search for chargino-neutralino production in events with Higgs and W bosons using 137 fb$^{?1}$ of proton-proton collisions at $ \sqrt{s} $ = 13 TeV AAD 2020R EPJ C80 691 Search for direct production of electroweakinos in final states with one lepton, missing transverse momentum and a Higgs boson decaying into two $b$-jets in $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector AAD 2020AN JHEP 2010 005 Search for direct production of electroweakinos in final states with missing transverse momentum and a Higgs boson decaying into photons in pp collisions at $ \sqrt{s} $ = 13 TeV with the ATLAS detector AAD 2020I PR D101 052005 Searches for electroweak production of supersymmetric particles with compressed mass spectra in $\sqrt{s}=$ 13 TeV $pp$ collisions with the ATLAS detector AAD 2020K PR D101 072001 Search for chargino-neutralino production with mass splittings near the electroweak scale in three-lepton final states in $\sqrt {s}$=13 TeV $pp$ collisions with the ATLAS detector SIRUNYAN 2020AU PRL 124 041803 Search for Supersymmetry with a Compressed Mass Spectrum in Events with a Soft $\tau$ Lepton, a Highly Energetic Jet, and Large Missing Transverse Momentum in Proton-Proton Collisions at $\sqrt{s}=$ TeV AABOUD 2019AU PR D100 012006 Search for chargino and neutralino production in final states with a Higgs boson and missing transverse momentum at $\sqrt{s} = 13$ TeV with the ATLAS detector SIRUNYAN 2019BU JHEP 1908 150 Search for supersymmetry with a compressed mass spectrum in the vector boson fusion topology with 1-lepton and 0-lepton final states in proton-proton collisions at $\sqrt{s}=$ 13 TeV AABOUD 2018BT EPJ C78 995 Search for electroweak production of supersymmetric particles in final states with two or three leptons at $\sqrt{s}=13\,$TeV with the ATLAS detector AABOUD 2018AY EPJ C78 154 Search for the direct production of charginos and neutralinos in final states with tau leptons in $\sqrt{s} = $ 13 TeV $pp$ collisions with the ATLAS detector AABOUD 2018CK PR D98 092002 Search for pair production of higgsinos in final states with at least three $b$-tagged jets in $\sqrt{s} = 13$ TeV $pp$ collisions using the ATLAS detector AABOUD 2018CO PR D98 092012 Search for chargino-neutralino production using recursive jigsaw reconstruction in final states with two or three charged leptons in proton-proton collisions at $\sqrt{s}=13$ TeV with the ATLAS detector AABOUD 2018U PR D97 092006 Search for photonic signatures of gauge-mediated supersymmetry in 13 TeV $pp$ collisions with the ATLAS detector AABOUD 2018R PR D97 052010 Search for electroweak production of supersymmetric states in scenarios with compressed mass spectra at $\sqrt{s}=13$ TeV with the ATLAS detector SIRUNYAN 2018AJ PL B782 440 Search for new physics in events with two soft oppositely charged leptons and missing transverse momentum in proton-proton collisions at $\sqrt{s}=$ 13 TeV SIRUNYAN 2018DP JHEP 1811 151 Search for supersymmetry in events with a $\tau$ lepton pair and missing transverse momentum in proton-proton collisions at $\sqrt{s} =$ 13 TeV SIRUNYAN 2017AW JHEP 1711 029 Search for Electroweak Production of Charginos and Neutralinos in ${{\mathit W}}{{\mathit H}}$ Events in Proton-Proton Collisions at $\sqrt {s }$ = 13 TeV AAD 2016AA PR D93 052002 Search for the Electroweak Production of Supersymmetric Particles in $\sqrt {s }$ = 8 TeV ${{\mathit p}}{{\mathit p}}$ Collisions with the ATLAS Detector AAD 2015BA EPJ C75 208 Search for Direct Pair Production of a Chargino and a Neutralino Decaying to the 125 GeV Higgs Boson in $\sqrt {s }$ = 8 TeV ${{\mathit p}}{{\mathit p}}$ Collisions with the ATLAS Detector AAD 2014H JHEP 1404 169 Search for Direct Production of Charginos and Neutralinos in Events with Three Leptons and Missing Transverse Momentum in $\sqrt {s }$ = 8 TeV ${{\mathit p}}{{\mathit p}}$ Collisions with the ATLAS Detector AAD 2014X PR D90 052001 Search for Supersymmetry in Events with Four or More Leptons in $\sqrt {s }$ = 8 TeV ${{\mathit p}}{{\mathit p}}$ Collisions with the ATLAS Detector AAD 2014G JHEP 1405 071 Search for Direct Production of charginos, neutralinos and sleptons in Final States with Two Leptons and Missing Transverse Momentum in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 8 TeV with the ATLAS Detector KHACHATRYAN 2014I EPJ C74 3036 Searches for Electroweak Production of charginos, neutralinos, and sleptons Decaying to Leptons and ${{\mathit W}}$, ${{\mathit Z}}$, and Higgs Bosons in ${{\mathit p}}{{\mathit p}}$ Collisions at 8 TeV AAD 2013 PL B718 841 Search for Direct Production of Charginos and Neutralinos in Events with Three Leptons and Missing Transverse Momentum in $\sqrt {s }$ = 7 TeV ${{\mathit p}}{{\mathit p}}$ Collisions with the ATLAS Detector AAD 2012AS PRL 108 261804 Search for Supersymmetry in Events with Three Leptons and Missing Transverse Momentum in $\sqrt {s }$ = 7 TeV ${{\mathit p}}{{\mathit p}}$ Collisions with the ATLAS Detector AAD 2012T PL B709 137 Searches for Supersymmetry with the ATLAS Detector using Final States with Two Leptons and Missing Transverse Momentum in $\sqrt {s }$ = 7 TeV Proton$−$Proton Collisions CHATRCHYAN 2012BJ JHEP 1211 147 Search for Electroweak Production of Charginos and Neutralinos using Leptonic Final States in ${{\mathit p}}{{\mathit p}}$ Collisions at $\sqrt {s }$ = 7 TeV ABREU 2000W PL B489 38 Limits on the Masses of Supersymmetric Particles at $\sqrt {s }$ = 189-GeV