General features of supersymmetric signals at the ILC: Solving the CERN LHC inverse problem

We present the first detailed, large-scale study of the minimal supersymmetric standard model (MSSM) at the $\sqrt{s}=500\text{ }\text{ }\mathrm{GeV}$ International Linear Collider (ILC), including full standard model backgrounds and detector simulation. This is the first realistic study of the capabilities of the ILC examining the physics of many distinct points in MSSM parameter space which are not linked to a particular supersymmetry (SUSY) breaking mechanism. Specifically, we investigate 242 points in the MSSM parameter space, which we term models, that correspond to the 162 pairs of models that were found by Arkani-Hamed et al. to give indistinguishable signatures at the LHC. We first determine whether the production of the various SUSY particles is visible above the standard model background for each of these parameter space points, and then make a detailed comparison of their various signatures. Assuming an integrated luminosity of $500\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ with 80% electron beam polarization, we find that only 82 out of 242 models lead to visible signatures of some kind with a significance $\ensuremath{\ge}5$ and that only 57 (63) out of the 162 model pairs are distinguishable at $5\text{ }(3)\ensuremath{\sigma}$. Our analysis includes PYTHIA and CompHEP SUSY signal generation, full matrix element SM backgrounds for all $2\ensuremath{\rightarrow}2$, $2\ensuremath{\rightarrow}4$ and $2\ensuremath{\rightarrow}6$ processes, ILC-specific initial state radiation and beamstrahlung generated via WHIZARD/GuineaPig, and employs the fast SiD detector simulation org.lcsim. If SUSY is light, the ILC will do a good job at examining its details.