The Production of Charginos/Neutralinos and Sleptons at Hadron Colliders

Abstract

We analyse the production of charginos/neutralinos and sleptons at the hadron colliders Tevatron and LHC in the direct channels: $p\bar{p}/pp \to \tildeχ_i \tildeχ_j + X$ and $\tilde{\ell} \bar{\tilde{\ell}'} +X$. The cross sections for these reactions are given in next-to-leading order SUSY QCD. By including the higher-order corrections, the predictions become theoretically stable, being nearly independent of the factorization and renormalization scales. Since the corrections increase the cross sections, the discovery range for these particles is extended in the refined analysis.

Figures (4)

• Figure 1: Basic diagrams for the production of chargino/neutralino pairs at hadron colliders in quark-antiquark collisions; (b) generic diagrams of SUSY-QCD corrections, comprising vertices, box diagrams, and diagrams for three-parton final states.
• Figure 2: Dependence of the cross sections for the production of $\tilde{\chi}_1^+ \tilde{\chi}_2^0$ pairs on the factorization/renormalization scale $Q$ in leading order and next-to-leading order SUSY QCD for the mSUGRA point defined in the text. The scale $Q$ is given in units of the average of the $\tilde{\chi}_1^+$ and $\tilde{\chi}_2^0$ masses $m(\tilde{\chi})$.
• Figure 3: (a) $K$-factors for hadroproduction of chargino/neutralino pairs in NLO SUSY QCD, and (b) the NLO cross sections at Tevatron and LHC. The parameters are derived from the mSUGRA point defined in the text, but varying the gaugino mass $m_{1/2}$; the factorization/renormalization scale is taken at the average chargino/neutralino mass. The mass at the lower $x$-axis is identified with the chargino/neutralino mass or the heavier of the chargino/neutralino masses in the pairs. [The $\tilde{\chi}_1^+$ and $\tilde{\chi}_2^0$ masses nearly coincide.]
• Figure 4: (a) $K$-factors for hadroproduction of slepton pairs in NLO SUSY QCD as a function of the squark mass $m_{\tilde{q}}$ for a gluino mass of 200 GeV and for slepton masses ${\tilde{e}_R}/{\tilde{e}_L}/{\tilde{\nu}_L} = 120/150/135$ GeV. (b) The NLO cross sections at Tevatron and LHC as a function of the slepton masses [${\tilde{e}}$ mass in mixed pairs] for squark/gluino masses fixed at 200 GeV. In both figures, the factorization/renormalization scale is taken at the average slepton mass.