Benchmark Models, Planes, Lines and Points for Future SUSY Searches at the LHC

TL;DR

This work presents a structured framework of SUSY benchmark models and subspaces (planes, lines, points) to standardize and extend the interpretation of LHC searches. By incorporating CMSSM, NUHM, mGMSB, mAMSB, MM-AMSB, p19MSSM, RPV, and NMSSM, the authors provide concrete, testable spectra and signature-topologies that can be updated as data accrue, including relic-density considerations and NLSP phenomenology. They discuss how current SUSY fits shape benchmark choices, and they offer explicit lines and points designed to probe diverse mass hierarchies, decay modes, and experimental signatures while keeping input spectra available (Les Houches format). The framework aims to facilitate cross-model comparisons, detector performance tests, and efficient exploration of higher-mass regions as the LHC advances, while acknowledging that cosmological constraints and alternative DM scenarios may affect the relevance of certain CMSSM-like benchmarks. Overall, the paper delivers a practical, extensible mapping of theoretically motivated SUSY scenarios into actionable experimental benchmarks across a broad model landscape.

Abstract

We define benchmark models for SUSY searches at the LHC, including the CMSSM, NUHM, mGMSB, mAMSB, MM-AMSB and p19MSSM, as well as models with R-parity violation and the NMSSM. Within the parameter spaces of these models, we propose benchmark subspaces, including planes, lines and points along them. The planes may be useful for presenting results of the experimental searches in different SUSY scenarios, while the specific benchmark points may serve for more detailed detector performance tests and comparisons. We also describe algorithms for defining suitable benchmark points along the proposed lines in the parameter spaces, and we define a few benchmark points motivated by recent fits to existing experimental data.

Figures (2)

• Figure 1: CMSSM fit points are projected on (upper panel) the $(m_0, m_{1/2})$ plane and (lower panel) the $(m_{1/2}, \tan\beta)$ plane. The best-fit points for different data sets are indicated by different symbols: closed stars for pre-LHC fits (Allanach Allanach:2011ut, Fittino Bechtle:2011dm, MC Buchmueller:2011aa, SuperBayes Trotta:2008bp), diamonds for fits including the first SUSY searches by CMS and ATLAS (Allanach Allanach:2011ut, MC Buchmueller:2011aa), triangles including all relevant 2010 LHC data (Allanach Allanach:2011wi, Bertone Bertone:2011nj, Fittino Bechtle:2011it, MC Buchmueller:2011ki), squares for estimates of the impacts of LHC data sets with 1, 2, 7 fb$^{-1}$ in the absence of a SUSY discovery Bechtle:2011dm, and open stars for fits including 1 fb$^{-1}$ of LHC data Farina:2011bhEPS. Also shown as crosses are two older benchmark points: SPS1a Allanach:2002nj and a similar benchmark point B$^{\prime \prime}$bench. The various symbols are also coded with different colours for different fitting groups, as shown in the legend. The line illustrates the trend of these fits as stronger constraints are incorporated.
• Figure 2: The CMSSM $(m_0, m_{1/2})$ planes for (left) $\tan \beta = 10, \mu > 0$ and $A_0 = 0$, and (right) $\tan \beta = 40, \mu > 0$ and $A_0 = - 500$ GeV. In the brown shaded regions at small $m_0$ the LSP is charged, in the pink shaded regions at large $m_0$ there is no consistent electroweak vacuum, the green shaded regions are excluded by $b \to s \gamma$, and the grey shaded regions are favoured by $(g-2)_\mu$ at the 1- (2-)$\sigma$ level indicated by dashed (solid) lines. LEP searches for charginos exclude the regions below the near-horizontal black dashed lines, LEP searches for the Higgs boson exclude the regions below the near-horizontal red dot-dashed lines, and LHC searches exclude the regions below the purple lines. The benchmark lines are solid black, and the dots denote the benchmark points spaced regularly along these lines. The dark blue strips yield the correct cold dark matter density in the CMSSM. All experimental numbers and the corresponding references can be found in Buchmueller:2011ki.