Implications of Initial LHC Searches for Supersymmetry

Abstract

The CMS and ATLAS Collaborations have recently published the results of initial direct LHC searches for supersymmetry analyzing ~ 35/pb of data taken at 7 TeV in the centre of mass. We incorporate these results into a frequentist analysis of the probable ranges of parameters of simple versions of the minimal supersymmetric extension of the Standard Model (MSSM), namely the constrained MSSM (CMSSM), a model with common non-universal Higgs masses (NUHM1), the very constrained MSSM (VCMSSM) and minimal supergravity (mSUGRA). We present updated predictions for the gluino mass, m_gl, the light Higgs boson mass, M_h, BR(B_s to mu mu) and the spin-independent dark matter scattering cross section, sigma_SI. The CMS and ATLAS data make inroads into the CMSSM, NUHM1 and VCMSSM (but not mSUGRA) parameter spaces, thereby strengthening previous lower limits on sparticle masses and upper limits on sigma_SI in the CMSSM and VCMSSM. The favoured ranges of BR(B_s to mu mu) in the CMSSM, VCMSSM and mSUGRA are close to the Standard Model, but considerably larger values of BR(B_s to mu mu) are possible in the NUHM1. Applying the CMS and ATLAS constraints improves the consistency of the model predictions for M_h with the LEP exclusion limits.

Figures (7)

• Figure 1: The $(m_0, m_{1/2})$ planes in the CMSSM (upper left), NUHM1 (top right), VCMSSM (lower left) and mSUGRA (lower right). In each panel, we show the 68 and 95% CL contours (red and blue, respectively) both after applying the CMS CMSsusy and ATLAS ATLASsusy constraints (dashed and solid lines, respectively) and beforehand (dotted lines). Also shown as open (solid) green stars are the best-fit points found after applying the CMS (ATLAS) constraints in each model (see text), and as green 'snowflakes' the previous best-fit points.
• Figure 2: The $(\tan\beta, m_{1/2})$ planes in the CMSSM (upper left), NUHM1 (top right), VCMSSM (lower left) and mSUGRA (lower right). The line styles and stars have the same meanings as in Fig. \ref{['fig:m0m12']}.
• Figure 3: The one-parameter $\chi^2$ likelihood functions for the gluino mass $m_{\tilde{g}}$ in the CMSSM (upper left), NUHM1 (top right), VCMSSM (lower left) and mSUGRA (lower right). In each panel, we show the $\chi^2$ function including the CMS and ATLAS CMSsusyATLASsusy constraints as dashed and solid lines, respectively, and the previous $\chi^2$ function as a dotted line.
• Figure 4: The one-parameter $\chi^2$ likelihood functions for the lightest MSSM Higgs mass $M_h$ in the CMSSM (upper left), NUHM1 (top right), VCMSSM (lower left) and mSUGRA (lower right). In each panel, we show the $\chi^2$ functions including the CMS and ATLAS CMSsusyATLASsusy constraints as dashed (solid) lines, the latter with a red band indicating the estimated theoretical uncertainty in the calculation of $M_h$ of $\sim 1.5 \,\, \mathrm{GeV}$, and the pre-LHC $\chi^2$ function is shown as a dotted line.
• Figure 5: The one-parameter $\chi^2$ likelihood functions for ${\rm BR}(B_s \to \mu^+\mu^-)$ in the CMSSM (upper left), NUHM1 (top right), VCMSSM (lower left) and mSUGRA (lower right). In each panel, we show the $\chi^2$ function including the CMS and ATLAS CMSsusyATLASsusy constraints as dashed and solid lines, respectively, and the previous $\chi^2$ function as a dotted line.