TY - JOUR
T1 - Combined collider constraints on neutralinos and charginos
AU - GAMBIT Collaboration
AU - Athron, Peter
AU - Balázs, Csaba
AU - Buckley, Andy
AU - Cornell, Jonathan M.
AU - Danninger, Matthias
AU - Farmer, Ben
AU - Fowlie, Andrew
AU - Gonzalo, Tomás E.
AU - Harz, Julia
AU - Jackson, Paul
AU - Kudzman-Blais, Rose
AU - Kvellestad, Anders
AU - Martinez, Gregory D.
AU - Petridis, Andreas
AU - Raklev, Are
AU - Rogan, Christopher
AU - Scott, Pat
AU - Sharma, Abhishek
AU - White, Martin
AU - Zhang, Yang
N1 - Publisher Copyright:
© 2019, The Author(s).
PY - 2019/5/1
Y1 - 2019/5/1
N2 - 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 [InlineEquation not available: see fulltext.] 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 [InlineEquation not available: see fulltext.] = (8–155, 103–260, 130–473, 219–502) GeV and chargino masses of [InlineEquation not available: see fulltext.] = (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 σ, 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 2.9σ. 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.
AB - 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 [InlineEquation not available: see fulltext.] 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 [InlineEquation not available: see fulltext.] = (8–155, 103–260, 130–473, 219–502) GeV and chargino masses of [InlineEquation not available: see fulltext.] = (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 σ, 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 2.9σ. 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.
UR - http://www.scopus.com/inward/record.url?scp=85065643190&partnerID=8YFLogxK
U2 - 10.1140/epjc/s10052-019-6837-x
DO - 10.1140/epjc/s10052-019-6837-x
M3 - Article
AN - SCOPUS:85065643190
SN - 1434-6044
VL - 79
JO - European Physical Journal C
JF - European Physical Journal C
IS - 5
M1 - 395
ER -