Top Partners at the LHC: Spin and Mass Measurement

Abstract

If one takes naturalness seriously and also assumes a weakly coupled extension of the Standard Model (SM) then there are predictions for phenomenology that can be inferred in a model independent framework. The first such prediction is that there must be some colored particle with mass O(TeV) that cancels the top loop contribution to the quadratic divergence of the Higgs mass. In this paper we begin a model independent analysis of the phenomenology of this "top partner," t'. We make one additional assumption that it is odd under a parity which is responsible for the stability of a WIMP dark matter candidate, N. We focus on three questions to be explored at the LHC: discovery opportunities, mass determination, and spin determination of this top partner. We find that within a certain region of masses for the t' and N, t'\bar{t'} is easily discovered in the t\bar{t}+2N decay with the tops decaying fully hadronically. We show that without having to rely on other channels for new physics that for a a given t' spin the masses of t' and N can be measured using kinematic information (e.g. average MET or H_T) and total cross section. A degeneracy due to the spin remains, but with several hundred inverse fb of luminosity we demonstrate potentially useful new methods for determining the t' spin over a wide range of masses. Our methods could be useful for distinguishing supersymmetric and non-supersymmetric models.

arXiv comment28 pages, 5 figures

References in corpus (29)

• Big Bang Nucleosynthesis (in "The Review of Particle Properties" 2004)
• New Generation of Parton Distributions with Uncertainties from Global QCD Analysis
• ALPGEN, a generator for hard multiparton processes in hadronic collisions
• Bounds on Universal Extra Dimensions
• The Littlest Higgs
• MadEvent: Automatic Event Generation with MadGraph
• Measuring masses of semi-invisibly decaying particles pair produced at hadron colliders
• Automatic Generation of Tree Level Helicity Amplitudes
• The Twin Higgs: Natural Electroweak Breaking from Mirror Symmetry
• TeV Symmetry and the Little Hierarchy Problem
• m_T2 : the truth behind the glamour
• Little Hierarchy, Little Higgses, and a Little Symmetry
• Physics potential and experimental challenges of the LHC luminosity upgrade
• Precision SUSY Measurements at LHC
• Bosonic Supersymmetry? Getting Fooled at the LHC
• Phenomenology of the Littlest Higgs with T-Parity
• T Parity and the Littlest Higgs
• Discrimination of Supersymmetry and Universal Extra Dimensions at Hadron Colliders
• Distinguishing Spins in Supersymmetric and Universal Extra Dimension Models at the Large Hadron Collider
• Determining the spin of supersymmetric particles at the LHC using lepton charge asymmetry
• Supersymmetry and the LHC Inverse Problem
• Measurement of SUSY masses via cascade decays for SPS 1a
• Measuring slepton spin at the LHC
• Top Partners in Little Higgs Theories with T-parity
• Contrasting Supersymmetry and Universal Extra Dimensions at the CLIC Multi-TeV e+e- Collider
• Measurement of the Gluino Mass via Cascade Decays for SPS 1a
• Fittino, a program for determining MSSM parameters from collider observables using an iterative method
• Invariant mass distributions in cascade decays
• Improved Measurement of ttZ Couplings at the LHC

Cited by in corpus (95)

• Natural SUSY Endures
• Stop Reconstruction with Tagged Tops
• Strategies to Identify Boosted Tops
• Model Independent Framework for Searches of Top Partners
• Natural Dark Matter from an Unnatural Higgs Boson and New Colored Particles at the TeV Scale
• Using Subsystem MT2 for Complete Mass Determinations in Decay Chains with Missing Energy at Hadron Colliders
• The Hunt for New Physics at the Large Hadron Collider
• The Status of GMSB After 1/fb at the LHC
• Physics searches at the LHC
• Dark Matter Particle Spectroscopy at the LHC: Generalizing MT2 to Asymmetric Event Topologies
• A Review of the Mass Measurement Techniques proposed for the Large Hadron Collider
• Phenomenology of Littlest Higgs Model with T-parity: including effects of T-odd fermions
• Spin Measurements in Cascade Decays at the LHC
• Exploring the Higgs Portal with 10/fb at the LHC
• LHC and Dark Matter Signals of Improved Naturalness
• Measuring Supersymmetry
• Hunting for the Top Partner in the Littlest Higgs Model with T-parity at the LHC
• It's a Gluino!
• \sqrt{s}_min: a global inclusive variable for determining the mass scale of new physics in events with missing energy at hadron colliders
• Polarized Tops from Stop Decays at the LHC
• BRIDGE: Branching Ratio Inquiry/Decay Generated Events
• Natural Supersymmetry at the LHC
• Stops and MET: the shape of things to come
• A model independent spin analysis of fundamental particles using azimuthal asymmetries
• Vacuum Instabilities with a Wrong-Sign Higgs-Gluon-Gluon Amplitude
• Using kinematic boundary lines for particle mass measurements and disambiguation in SUSY-like events with missing energy
• Precise reconstruction of sparticle masses without ambiguities
• The "Top Priority" at the LHC
• Natural SUSY in Plain Sight
• How to Improve Top Tagging
• Dark Matter-Motivated Searches for Exotic 4th Generation Quarks in Tevatron and Early LHC Data
• Top Quark Pair plus Large Missing Energy at the LHC
• Alternatives to an Elementary Higgs
• The Dark Top
• Searching for Direct Stop Production in Hadronic Top Data at the LHC
• A Review of Spin Determination at the LHC
• Collider Signature of T-quarks
• The race for supersymmetry: using mT2 for discovery
• Constraining Top partner and Naturalness at the LHC and TLEP
• Single production of the top partners at high energy colliders
• Testing the Littlest Higgs Model with T-parity at the Large Hadron Collider
• Impact of Single-Top Measurement to Littlest Higgs Model with T-Parity
• Spin Correlations in Decay Chains Involving W Bosons
• Search for Higgs bosons of the Universal Extra Dimensions at the Large Hadron Collider
• A top-squark hunter's guide
• Model Independent Constraints Among the Wtb, Zbb, and Ztt Couplings
• Identifying Multi-Top Events from Gluino Decay at the LHC
• Testing Gluino Spin with Three-Body Decays
• Search for single production of the vector-like top partner at the 14 TeV LHC
• Benchmarking an Even Better HEPTopTagger
• Next-to-Leading Order Cross Sections for New Heavy Fermion Production at Hadron Colliders
• Kinematic Cusps With Two Missing Particles I: Antler Decay Topology
• Opening the black box of neural nets: case studies in stop/top discrimination
• Phenomenology of Top Partners at the ILC
• Little M-theory
• Exotic Top Partners and Little Higgs
• Search for single production of vector-like top partners at the Large Hadron Electron Collider
• Kinematic Cusps with Two Missing Particles II: Cascade Decay Topology
• Search for single production of the heavy vectorlike $T$ quark with $T\to th$ and $h\to \gamma \gamma$ at the high-luminosity LHC
• Mass reconstruction with $M_2$ under constraint in semi-invisible production at a hadron collider
• Collider signature of $U_1$ Leptoquark and constraints from $b\to c$ observables
• SUSY-Yukawa Sum Rule at the LHC
• Naturalness, b to s gamma, and SUSY Heavy Higgses
• The production and decay of the top partner $T$ in the left-right twin higgs model at the ILC and CLIC
• Structure of Fat Jets at the Tevatron and Beyond
• Distinguishing the Littlest Higgs model with T-parity from supersymmetry at the LHC using trileptons
• Spin Determination via Third Generation Cascade Decays
• Improved mass measurement using the boundary of many-body phase space
• Towards Measuring the Stop Mixing Angle at the LHC
• A Spin-1 Top Quark Superpartner
• Distinguishing spins in decay chains with photons at the Large Hadron Collider
• Initial determination of the spins of the gluino and squarks at LHC
• Determining the Dark Matter Particle Mass through Antler Topology Processes at Lepton Colliders
• Same-Sign Charginos and Majorana Neutralinos at the LHC
• Precision Measurements of Little Higgs Parameters at the International Linear Collider
• Phenomenology of Universal Extra Dimensions
• Spin Discrimination in Three-Body Decays
• Spheres To Jets: Tuning Event Shapes with 5d Simplified Models
• Model Discrimination at the LHC: a Case Study
• Multi-Dimensional Phase Space Methods for Mass Measurements and Decay Topology Determination
• Measuring Masses in Semi-Invisible Final States at Electron-Positron Colliders
• Kinematic Edges with Flavor Oscillation and Non-Zero Widths
• Top quark induced vacuum misalignment in little higgs models
• Large Jet Multiplicities and New Physics at the LHC
• T-odd top partner pair production in the dilepton final states at the LHC in the littlest Higgs Model with T-parity
• Odd Decays from Even Anomalies: Gauge Mediation Signatures Without SUSY
• Dreaming Awake: Disentangling the Underlying Physics in Case of a SUSY-like Discovery at the LHC
• A New Method for the Spin Determination of Dark Matter
• Searching for supersymmetry scalelessly
• Spin and Chirality Effects in Antler-Topology Processes at High Energy $e^{+}{e}^{-}$ Colliders
• Dissecting new physics models through kinematic edges
• Effects of Anomalous Couplings on Spin Determination in Cascade Decays
• Applying Machine Learning Techniques To Intermediate-Length Cascade Decays
• Mono-b events from single stop production at the HL-LHC and HE-LHC
• Large Jet Multiplicities and Natural Supersymmetry at the LHC