Distinguishing Spins in Decay Chains at the Large Hadron Collider

Abstract

If new particles are discovered at the LHC, it will be important to determine their spins in as model-independent a way as possible. We consider the case, commonly encountered in models of physics beyond the Standard Model, of a new scalar or fermion $D$ decaying sequentially into other new particles $C,B,A$ via the decay chain $D\to Cq$, $C\to B{l}^{near}$, $B\to A{l}^{far}$, $l^{near}$ and $l^{far}$ being opposite-sign same-flavour charged leptons and $A$ being invisible. We compute the observable 2- and 3-particle invariant mass distributions for all possible spin assignments of the new particles, and discuss their distinguishability using a quantitative measure known as the Kullback-Leibler distance.

23 pages, 12 figures uses Feynarts; v2 has minor corrections and a new section 4.2 which includes the 3D analysis described in hep-ph/0606212; v3 has reference added and typos fixed - matches journal version; v4 corrects typo in equation B9

References in corpus (2)

• It's a Gluino!
• Constrained invariant mass distributions in cascade decays. The shape of the "$m_{qll}$-threshold" and similar distributions

Cited by in corpus (30)

• Simplified Models for a First Characterization of New Physics at the LHC
• Using Subsystem MT2 for Complete Mass Determinations in Decay Chains with Missing Energy at Hadron Colliders
• Unifying inflation and dark matter with neutrino masses
• Measuring Supersymmetry
• \sqrt{s}_min: a global inclusive variable for determining the mass scale of new physics in events with missing energy at hadron colliders
• A model independent spin analysis of fundamental particles using azimuthal asymmetries
• Using kinematic boundary lines for particle mass measurements and disambiguation in SUSY-like events with missing energy
• Precise reconstruction of sparticle masses without ambiguities
• Constrained invariant mass distributions in cascade decays. The shape of the "$m_{qll}$-threshold" and similar distributions
• Spin Analysis of Supersymmetric Particles
• Squark Flavor Violation at the LHC
• Spin Correlations in Decay Chains Involving W Bosons
• Testing Gluino Spin with Three-Body Decays
• Precision Determination of Invisible-Particle Masses at the CERN LHC: II
• $\tau$ Polarization in SUSY Cascade Decays
• NLO production of W' bosons at hadron colliders using the MC@NLO and POWHEG methods
• The study of sq_L sq_L production at LHC in the l^\pm l^\pm channel and sensitivity to other models
• The Interplay Between Collider Searches For Supersymmetric Higgs Bosons and Direct Dark Matter Experiments
• Distinguishing Supersymmetry From Universal Extra Dimensions or Little Higgs Models With Dark Matter Experiments
• Identification of the Origin of Monojet Signatures at the LHC
• Spin Determination via Third Generation Cascade Decays
• Determining Spins of Metastable Sleptons at the Large Hadron Collider
• Squark Cascade Decays to Charginos/Neutralinos: Gluon Radiation
• Distinguishing spins in decay chains with photons at the Large Hadron Collider
• Probing Supersymmetry With Third-Generation Cascade Decays
• Same-Sign Charginos and Majorana Neutralinos at the LHC
• Model Discrimination at the LHC: a Case Study
• Mass Determination of New Particle States
• Complementarity of the CERN Large Hadron Collider and the $e^{+}{e}^{-}$ International Linear Collider
• Complementarity of LHC and ILC