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

Abstract

We present a focused study of a predictive unified model whose measurable consequences are immediately relevant to early discovery prospects of supersymmetry at the LHC. ATLAS and CMS have released their analysis with 35 pb −1 of data and the model class we discuss is consistent with this data. It is shown that with an increase in luminosity the LSP dark matter mass and the gluino mass can be inferred from simple observables such as kinematic edges in leptonic channels and peak values in effective mass distributions. Specifically, we consider cases in which the neutralino is of low mass and where the relic density consistent with WMAP observations arises via the exchange of Higgs bosons in unified supergravity models. The magnitudes of the gaugino masses are sharply limited to focused regions of the parameter space, and in particular the dark matter mass lies in the range ∼ (50 − 65) GeV with an upper bound on the gluino mass of 575 GeV, with a typical mass of 450 GeV. We find that all model points in this paradigm are discoverable at the LHC at √ s = 7 TeV. We determine lower bounds on the entire sparticle spectrum in this model based on existing experimental constraints. In addition, we find the spin-independent cross section for neutralino scattering on nucleons to be generally in the range of σ SĨ χ 0 1 p = 10 −46±1 cm 2 with much higher cross sections also possible. Thus direct detection experiments such as CDMS and XENON already constrain some of the allowed parameter space of the low mass gaugino models and further data will provide important cross-checks of the model assumptions in the near future.

Tuning supersymmetric models at the LHC: a comparative analysis at two-loop level.

“…The data output was then filtered by the experimental constraints. The run time to generate the phase space points of the five models was about 15000 one-day jobs on the CERN computing service, and each plot was generated from ≈ 4 × 10 7 points in a random scan of the parameter space (for alternative and recent data analysis see [44][45][46][47][48][49][50]). …”

Benchmark models, planes, lines and points for future SUSY searches at the LHC

“…Several groups have published SUSY fits to the available data, both before and after incorporation of the published 2010 LHC data [91,[96][97][98][99][100][101][102][103][104][105][106][107][108][109], some fits have been made [110][111][112] incorporating the preliminary CMS and ATLAS results based on ∼1 fb −1 of data, and attempts have also been made to foresee the evolution of these fits if the Table 1 List of the SPS benchmark points, with their status with respect to the current limits from LHC SUSY searches, adapted from [91]. For each point the columns labelled A, B, C and D give the cross section for each of the signal regions used in the 35/pb AT-LAS 0-lepton analysis [10].…”

Ultrahigh jet multiplicity signal of stringy no-scaleF−SU(5)at thes=Li1, Maxin2, Nanopoulos3 et al. 2011Phys. Rev. D5131360View full textAdd to dashboardCite

“…Data corresponding to the paltry integrated luminosity of 35 pb −1 has already been able to establish new constraints on the viable parameter space [1][2][3], due to the unprecedented center of mass collision energy now available. The search strategy for SUSY signals in the early LHC data has been actively and eagerly studied by quite a few groups [4][5][6][7][8], with particular focus on the parameter space featuring a traditional mass relationship between squarks and the gluino, such as a gluino heavier than all squarks or a gluino lighter than all squarks.…”