Fine-tuning implications for complementary dark matter and LHC SUSY searches

Abstract

The requirement that SUSY should solve the hierarchy problem without undue fine-tuning imposes severe constraints on the new supersymmetric states. With the MSSM spectrum and soft SUSY breaking originating from universal scalar and gaugino masses at the Grand Unification scale, we show that the low-fine-tuned regions fall into two classes that will require complementary collider and dark matter searches to explore in the near future. The first class has relatively light gluinos or squarks which should be found by the LHC in its first run. We identify the multijet plus E miss T signal as the optimal channel and determine the discovery potential in the first run. The second class has heavier gluinos and squarks but the LSP has a significant Higgsino component and should be seen by the next generation of direct dark matter detection experiments. The combined information from the 7 TeV LHC run and the next generation of direct detection experiments can test almost all of the CMSSM parameter space consistent with dark matter and EW constraints, corresponding to a fine-tuning not worse than 1:100. To cover the complete low-fine-tuned region by SUSY searches at the LHC will require running at the full 14 TeV CM energy; Open Access doi:10.1007/JHEP05(2011)120 JHEP05(2011)120in addition it may be tested indirectly by Higgs searches covering the mass range below 120 GeV.

Predictive signatures of supersymmetry: Measuring the dark matter mass and gluino mass with early LHC data

“…In Figure 2, we plot the distribution in m eff for two of our benchmark points using the cut C 1 of Eq. (19). The heavy solid line gives the supersymmetric signal events plus the SM background while the shaded area is the SM background.…”

“…In Figure 4 we plot this distribution for the same two benchmark models from Figure 2 after applying the cuts C 5 from Eq. (19).…”

“…Thus, some aspects of the minimal supergravity models where the relics annihilate near the light CP-even Higgs pole have been discussed in Ref. [14][15][16][17][18][19], which fall under the mass hierarchy denoted by mSP4 (supergravity mass pattern 4) [14,15], where, in particular, a clean edge in the dilepton invariant mass in this model class was noted in Ref. [15].…”

“…In addition, the very recent work of Ref. [19] studies electroweak symmetry breaking in an overlapping class of models with a focus on the µ parameter and radiative breaking.…”

“…The mass splitting between the gluino and the lighter gauginos is appreciable. Thus should this model class be realized in nature, the production of jets from the gluino should be seen at the LHC at √ s = 7 TeV with about a few inverse femtobarns of data [16], [22], [23], [24,25], [19].…”