Year: 2010
Type: article
Abstract: Motivated by dark-matter considerations in supersymmetric theories, we investigate in a fairly model-independent way the detection at the LHC of nearly degenerate gauginos with mass differences between a few GeV and about 30 GeV. Because of the degeneracy of gaugino states, the conventional leptonic signals are likely lost. We first consider the leading signal from gluino production and decay. We find that it is quite conceivable to reach a large statistical significance for the multijet plus missing energy signal with an integrated luminosity about $50\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$ ($50\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$) for a gluino mass of 500 GeV (1 TeV). If gluinos are not too heavy, less than about 1.5 TeV, this channel can typically probe gaugino masses up to about 100 GeV below the gluino mass. We then study the Drell-Yan type of gaugino pair production in association with a hard QCD jet, for gaugino masses in the range of 100--150 GeV. The signal observation may be statistically feasible with about $10\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$, but systematically challenging due to the lack of distinctive features for the signal distributions. By exploiting gaugino pair production through weak boson fusion, signals of large missing energy plus two forward-backward jets may be observable at a $4--6\ensuremath{\sigma}$ level above the large SM backgrounds with an integrated luminosity of $100--300\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$. Finally, we point out that searching for additional isolated soft muons in the range ${p}_{T}\ensuremath{\sim}3--10\text{ }\text{ }\mathrm{GeV}$ in the data samples discussed above may help to enrich the signal and to control the systematics. Significant efforts are made to explore the connection between the signal kinematics and the relevant masses for the gluino and gauginos, to probe the mass scales of the superpartners, in particular, the lightest supersymmetric particle dark matter.
Authors: Gian F. Giudice, Tao Han, Kai Wang, Lian-Tao Wang
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2143442771