Combined collider constraints on neutralinos and charginos

GAMBIT Collaboration:

Research output: Contribution to journalArticleResearchpeer-review

5 Citations (Scopus)

Abstract

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.

Original languageEnglish
Article number395
JournalEuropean Physical Journal C
Volume79
Issue number5
DOIs
Publication statusPublished - 1 May 2019

Keywords

  • Mass
  • Gaugino masses
  • Standard model (particle physics)

Cite this

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title = "Combined collider constraints on neutralinos and charginos",
abstract = "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.",
keywords = "Mass, Gaugino masses, Standard model (particle physics)",
author = "Peter Athron and Csaba Bal{\'a}zs and Andy Buckley and Cornell, {Jonathan M.} and Matthias Danninger and Ben Farmer and Andrew Fowlie and Gonzalo, {Tom{\'a}s E.} and Julia Harz and Paul Jackson and Rose Kudzman-Blais and Anders Kvellestad and Martinez, {Gregory D.} and Andreas Petridis and Are Raklev and Christopher Rogan and Pat Scott and Abhishek Sharma and Martin White and Yang Zhang and {GAMBIT Collaboration:}",
year = "2019",
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Combined collider constraints on neutralinos and charginos. / GAMBIT Collaboration:.

In: European Physical Journal C, Vol. 79, No. 5, 395, 01.05.2019.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Combined collider constraints on neutralinos and charginos

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

AU - GAMBIT Collaboration:

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.

KW - Mass

KW - Gaugino masses

KW - Standard model (particle physics)

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

VL - 79

JO - European Physical Journal C

JF - European Physical Journal C

SN - 1434-6044

IS - 5

M1 - 395

ER -