Detecting a Light Gravitino at Linear Collider to Probe the SUSY Breaking Scale

Abstract

If supersymmetry is dynamically broken at a low scale ($M_{susy}$), within a few orders of magnitude of the weak scale, then the lightest supersymmetric partner is the gravitino and the next to lightest supersymmetric partner is a neutralino ${\chi }_1^0$ with mass $m_{{\chi }_1^0}$, which can decay into a photon ($\gamma$) plus a gravitino ($\tilde{G}$). We study the detection of $e^{-}{e}^{+}\to {\chi }_1^0{\chi }_1^0\to \gamma \tilde{G}\gamma \tilde{G}$ at the proposed Linear Collider, and find the range of the parameters $M_{susy}$ and $m_{{\chi }_1^0}$ that can be accessible with a right-hand polarized electron beam at $\sqrt{S}=500$\,GeV, with 50\,${\mathrm{fb}}^{-1}$ integrated luminosity. We also discuss briefly the accessible range for current electron and hadron colliders.

Comments: 20 pages, LaTeX file and postscript figures