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arXiv · hep-ph/0611316

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

Guang Bian·Mike Bisset·Nicholas Kersting·Y. Liu·X. Wang
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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.

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Guang Bian, Mike Bisset, Nicholas Kersting, Y. Liu, X. Wang. 2006-11-27. Wedgebox analysis of four-lepton events from neutralino pair production at the LHC. https://doi.org/10.1140/epjc%2Fs10052-007-0472-7

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