Top-Quark Initiated Processes at High-Energy Hadron Colliders

Abstract

In hadronic collisions at high energies, the top-quark may be treated as a parton inside a hadron. Top-quark initiated processes become increasingly important since the top-quark luminosity can reach a few percent of the bottom-quark luminosity. In the production of a heavy particle $H$ with mass $m_H>m_t$, treating the top-quark as a parton allows us to resum large logarithms $\log (m_H^2/m_t^2$) arising from collinear splitting in the initial state. We quantify the effect of collinear resummation at the 14-TeV LHC and a future 100-TeV hadron collider, focusing on the top-quark open-flavor process $gg\to t\bar{t}H$ in comparison with $t\bar{t}\to H$ and $tg\to tH$ at the leading order (LO) in QCD. We employ top-quark parton distribution functions with appropriate collinear subtraction and power counting. We find that (1) Collinear resummation enhances the inclusive production of a heavy particle with $m_H\approx$ 5 TeV (0.5 TeV) by more than a factor of two compared to the open-flavor process at a 100-TeV (14-TeV) collider; (2) Top-quark mass effects are important for scales $m_H$ near the top-quark threshold, where the cross section is largest. We advocate a modification of the ACOT factorization scheme, dubbed m-ACOT, to consistently treat heavy-quark masses in hadronic collisions; (3) The scale uncertainty of the total cross section in m-ACOT is of about 20 percent at the LO. While a higher-order calculation is indispensable for a precise prediction, the LO cross section is well described by the process $t\bar{t}\to H$ using an effective factorization scale significantly lower than $m_H$. We illustrate our results by the example of a heavy spin-0 particle. Our main results also apply to the production of particles with spin-1 and 2.

arXiv comment30 pages, 9 figures, 1 table, matches version published in JHEP

References in corpus (30)

• The automated computation of tree-level and next-to-leading order differential cross sections, and their matching to parton shower simulations
• Parton distributions with LHC data
• Cuba - a library for multidimensional numerical integration
• Strong Dynamics and Electroweak Symmetry Breaking
• Quantum Gravity and Extra Dimensions at High-Energy Colliders
• On Kaluza-Klein States from Large Extra Dimensions
• The p_T Spectrum in Heavy-Flavour Hadroproduction
• The Anatomy of Electro-Weak Symmetry Breaking. I: The Higgs boson in the Standard Model
• RS1, Custodial Isospin and Precision Tests
• Leptoproduction of Heavy Quarks II -- A Unified QCD Formulation of Charged and Neutral Current Processes from Fixed-target to Collider Energies
• The p_T Spectrum in Heavy-Flavour Photoproduction
• Experimental Probes of Localized Gravity: On and Off the Wall
• Boosted objects: a probe of beyond the Standard Model physics
• Associated Higgs production with top quarks at the Large Hadron Collider: NLO QCD corrections
• Hard-scattering factorization with heavy quarks: A general treatment
• Heavy quarks in deep-inelastic scattering
• Charm electroproduction viewed in the variable-flavour number scheme versus fixed-order perturbation theory
• An Ordered Analysis of Heavy Flavour Production in Deep Inelastic Scattering
• Treatment of Heavy Quarks in Deeply Inelastic Scattering
• Open Heavy Flavor Production in QCD -- Conceptual Framework and Implementation Issues
• CTEQ6 Parton Distributions with Heavy Quark Mass Effects
• Higgs-Boson Production in Association with a Single Bottom Quark
• Higgs-Boson Production via Bottom-Quark Fusion
• Searching for the Kaluza-Klein Graviton in Bulk RS Models
• Higgs Working Group Report of the Snowmass 2013 Community Planning Study
• b-Initiated processes at the LHC: a reappraisal
• Higgs-Boson Production in Association with Bottom Quarks at Next-to-Leading Order
• Unbroken $SU(2)$ at a 100 TeV collider
• New Particles Working Group Report of the Snowmass 2013 Community Summer Study
• A Redux on "When is the Top Quark a Parton?"

Cited by in corpus (29)

• Physics Opportunities of a 100 TeV Proton-Proton Collider
• The Structure of the Proton in the LHC Precision Era
• Dynamical scales for multi-TeV top-pair production at the LHC
• Electroweak Splitting Functions and High Energy Showering
• Higgs production in bottom-quark fusion in a matched scheme
• Resummation and Matching of $b$-quark Mass Effects in $b\bar{b}H$ Production
• The Effective Vector Boson Approximation in High-Energy Muon Collisions
• Intrinsic charm in a matched general-mass scheme
• Doubly Charged Higgs Boson Production at Hadron Colliders
• Matched predictions for the $b\bar{b}H$ cross section at the 13 TeV LHC
• LePDF: Standard Model PDFs for High-Energy Lepton Colliders
• Vector and Axial-vector resonances in composite models of the Higgs boson
• Measuring the Top Yukawa Coupling at 100 TeV
• Anatomy of double heavy-quark initiated processes
• Heavy-flavor parton distributions without heavy-flavor matching prescriptions
• Weak Boson Fusion at 100 TeV
• Implementation of Angularly Ordered Electroweak Parton Shower in Herwig 7
• Automated Neutrino Jet and Top Jet Predictions at Next-to-Leading-Order with Parton Shower Matching in Effective Left-Right Symmetric Models
• Dark Matter from Electroweak Single Top Production
• Implications of Vector Boson Scattering Unitarity in Composite Higgs Models
• The top threshold effect in the $\gamma \gamma$ production at the LHC
• The impact of top-quark modelling on the exclusion limits in $\mathbf{t}\bar{\mathbf{t}}+\text{DM}$ searches at the LHC
• $t{Z}^{\prime }$ production at hadron colliders
• Probing top-antitop resonances with $t\bar{t}$ scattering at LHC14
• Inclusive Higgs Production at Large Transverse Momentum
• Kaluza-Klein gluons at 100 TeV: NLO corrections
• Parton Distributions at a 100 TeV Hadron Collider
• NLO QCD corrections to single vector-like top partner production in association with top quark at the LHC
• Weak bosons as partons below 10 TeV partonic center-of-momentum