Probing minimal supergravity at the CERN LHC for largetanβ

For large values of the minimal supergravity model parameter $\tan \beta ,$ the tau lepton and the bottom quark Yukawa couplings become large, leading to reduced masses of $\tau$ sleptons and b squarks relative to their first and second generation counterparts, and to enhanced decays of charginos and neutralinos to $\tau$ leptons and b quarks. We evaluate the reach of the CERN Large Hadron Collider (LHC) $\mathrm{pp}$ collider for supersymmetry in the MSUGRA model parameter space. We find that values of $m_{\tilde{g}}\sim 1500–2000\hspace{0.5em}\mathrm{GeV}$ can be probed with just $10\hspace{0.5em}{\mathrm{fb}}^{-1}$ of integrated luminosity for $\tan \beta$ values as high as 45, so that MSUGRA cannot escape the scrutiny of LHC experiments by virtue of having a large value of $\tan \beta .$ We also perform a case study of an MSUGRA model at $\tan \beta =45\mathrm{}$ where $Z_2\to \tau {\tilde{\tau }}_1$ and $W_1\to {\tilde{\tau }}_1{\nu }_{\tau }$ with $\sim 100\%$ branching fraction. In this case, at least within our simplistic study, we show that a di-tau mass edge, which determines the value of $m_{Z_2}-m_{Z_1},$ can still be reconstructed. This information can be used as a starting point for reconstructing SUSY cascade decays on an event-by-event basis, and can provide a strong constraint in determining the underlying model parameters. Finally, we show that for large $\tan \beta ,$ there can be an observable excess of $\tau$ leptons, and argue that $\tau$ signals might serve to provide new information about the underlying model framework.