Determination of supersymmetric masses using kinematic fits at the LHC

Abstract

In case of the discovery of supersymmetry at the LHC, the goal will be to identify the underlying theory, its fundamental parameters, and the masses of SUSY particles. We followed here the approach to reconstruct the decay chains in SUSY events under the assumption of common intermediate masses. These masses cannot be extracted from each event because of the unmeasured LSP momenta in case of R-parity conservation. But an ensemble of events can be over-constrained, if the decay chains are long enough, such that enough mass constraints are available. Here, we present a new method combining a) a SUSY mass scan, b) a kinematic fitting based on a genetic algorithm for decay chain reconstruction, and c) the usage of angular decay information to suppress the background from other SUSY processes. Taking into account the full combinatorial background and experimental resolutions in the most difficult case of the fully hadronic decay mode, we demonstrate, within one SUSY scenario, that this method can be used to derive a probability map of the SUSY parameter space.

15 pages, 15 figures

References in corpus (15)

• PYTHIA 6.4 Physics and Manual
• Measuring superparticle masses at hadron collider using the transverse mass kink
• Using Subsystem MT2 for Complete Mass Determinations in Decay Chains with Missing Energy at Hadron Colliders
• Accurate Mass Determinations in Decay Chains with Missing Energy
• Mass Determination of New States at Hadron Colliders
• Kinematic Cusps: Determining the Missing Particle Mass at Colliders
• Using kinematic boundary lines for particle mass measurements and disambiguation in SUSY-like events with missing energy
• The Precision Determination of Invisible-Particle Masses at the LHC
• A short comparison between m_T2 and m_CT
• Constrained invariant mass distributions in cascade decays. The shape of the "$m_{qll}$-threshold" and similar distributions
• Precision Determination of Invisible-Particle Masses at the CERN LHC: II
• Effects of QCD radiation on inclusive variables for determining the scale of new physics at hadron colliders
• Hidden Thresholds: A Technique for Reconstructing New Physics Masses at Hadron Colliders
• A Simple Mass Reconstruction Technique for SUSY particles at the LHC
• Mass Determination of New Particle States

Cited by in corpus (4)

• Dark Matter Particle Spectroscopy at the LHC: Generalizing MT2 to Asymmetric Event Topologies
• Detecting kinematic boundary surfaces in phase space: particle mass measurements in SUSY-like events
• Kinematic Edges with Flavor Splitting and Mixing
• Multi-Dimensional Phase Space Methods for Mass Measurements and Decay Topology Determination