Supersymmetric NLO QCD Corrections to Resonant Slepton Production and Signals at the Tevatron and the LHC

TL;DR

The paper addresses resonant slepton production in a baryon-triality SUSY framework, providing a comprehensive NLO QCD and SUSY-QCD calculation of total and differential cross sections for Tevatron and LHC energies. It augments fixed-order results with Collins-Soper-Sterman soft-gluon resummation and a careful matching to fixed-order calculations, and examines the running of the $\\lambda'$ coupling and the decoupling of heavy superpartners. The study finds significant SUSY-QCD corrections (up to ~35%) and enhanced precision due to reduced scale uncertainties, while delivering detailed slepton decay patterns and predictions for like-sign dimuon signals. By benchmarking analytic results against MC generators, the work also highlights discrepancies in p_T spectra and provides guidance for improving experimental analyses and event simulation in searches for baryon-tr triality SUSY signals.

Abstract

We compute the total cross section and the transverse momentum distribution for single charged slepton and sneutrino production at hadronic colliders including NLO supersymmetric and non-supersymmetric QCD corrections. The supersymmetric QCD corrections can be substantial. We also resum the gluon transverse momentum distribution and compare our results with two Monte Carlo generators. We compute branching ratios of the supersymmetric decays of the slepton and determine event rates for the like-sign dimuon final state at the Tevatron and at the LHC.

Figures (8)

• Figure 1: Generic Feynman diagrams for resonant slepton production, (a) LO; (b) QCD vertex corrections; (c) QCD self energy; (d) SUSY-QCD vertex correction; (e) SUSY-QCD self energy; (f) QCD real gluon radiation; (g) QCD Compton process.
• Figure 2: Single slepton production cross section at the Tevatron (lower curves) and at the LHC (upper curves). The $LQ\bar{D}$-coupling is set to $\lambda^{\prime}_{i11} = 0.01$. The CTEQ6 LO/NLO PDFs have been used, and renormalization and factorization scales have been identified with the slepton mass $\tilde{m}$.
• Figure 3: SUSY-QCD $K$-factor for resonant slepton production via $\lambda'_{i11}=0.01$ at the LHC, $\sqrt{S}=14$ TeV, for three sets of squark and gluino masses ($m_{\tilde{q}_L} = m_{\tilde{q}_R} = m_{\tilde{g}}$). Different values for the SUSY breaking parameter $A$ are chosen as indicated. For comparison we give also the QCD $K$-factor (solid lines). The CTEQ6 LO/NLO PDFs have been used, and renormalization and factorization scales have been identified with the slepton mass $\tilde{m}$.
• Figure 4: The same as Fig. \ref{['fig_Kfact_LHC']} but for the Tevatron.
• Figure 5: Differential transverse momentum distribution of the slepton at the Tevatron for the $u\overline{d}$ initiated process via $\lambda'_{i11}$. The two sets of curves correspond to slepton masses of $200$ and $500\,{\rm GeV}$. The different lines of each set denote the perturbative (dot dashed), asymptotic (dashed), summed (dotted) and full (solid) differential cross section.