Wedgebox analysis of four-lepton events from neutralino pair production at the LHC

Abstract

`Wedgebox' plots constructed by plotting the di-electron invariant mass versus the di-muon invariant mass from pp -> e^+e^- mu^+ mu^- + missing energy signature LHC events. Data sets of such events are obtained across the MSSM input parameter space in event-generator simulations, including cuts designed to remove SM backgrounds. Their study reveals several general features: (1)Regions in the MSSM input parameter space where a sufficient number of events are expected so as to be able to construct a clear wedgebox plot are delineated. (2)The presence of box shapes on a wedgebox plot either indicates the presence of heavy Higgs bosons decays or restricts the location to a quite small region of low μand M_2 values \lsim 200 GeV, a region denoted as the `lower island'. In this region, wedgebox plots can be quite complicated and change in pattern rather quickly as one moves around in the (μ, M_2) plane. (3)Direct neutralino pair production from an intermediate Z^{0*} may only produce a wedge-shape since only \widetildeχ_2^0\widetildeχ_3^0 decays can contribute significantly. (4)A double-wedge or wedge-protruding-from-a-box pattern on a wedgebox plot, which results from combining a variety of MSSM production processes, yields three distinct observed endpoints, almost always attributable to \widetildeχ_{2,3,4}^0 \to \widetildeχ_1^0 \ell^+\ell^- decays, which can be utilized to determine a great deal of information about the neutralino and slepton mass spectra and related MSSM input parameters. Wedge and double-wedge patterns are seen in wedgebox plots in another region of higher μand M_2 values, denoted as the`upper island.' Here the pattern is simpler and more stable as one moves across the (μ, M_2) input parameter space.

28 pages (LaTeX), 8 figures (encapsulated postscript)

References in corpus (4)

• Boosted Decision Trees as an Alternative to Artificial Neural Networks for Particle Identification
• Studies of Boosted Decision Trees for MiniBooNE Particle Identification
• Reconstructing Sparticle Mass Spectra using Hadronic Decays
• The Neutralino Sector in the U(1)-Extended Supersymmetric Standard Model

Cited by in corpus (8)

• A Review of the Mass Measurement Techniques proposed for the Large Hadron Collider
• Four-lepton LHC events from MSSM Higgs boson decays into neutralino and chargino pairs
• A Simple Mass Reconstruction Technique for SUSY particles at the LHC
• Hidden Thresholds: A Technique for Reconstructing New Physics Masses at Hadron Colliders
• Extracting MSSM Masses From Heavy Higgs Decays to Four Leptons at the LHC
• Testing a U(1) Solution to the Mu Problem
• Tau-Sneutrino NLSP and Multilepton Signatures at the LHC
• Transverse mass and invariant mass observables for measuring the mass of a semi-invisibly decaying heavy particle