Top-antitop production from $W_L^{+}{W}_L^{-}$ and $Z_L{Z}_L$ scattering under a strongly-interacting symmetry-breaking sector

Abstract

By using a Non-linear Electroweak Chiral Lagrangian, including the Higgs, coupled to heavy quarks, and the Equivalence Theorem, we compute (in the regime $M_t^2/v^2\ll \sqrt{s}{M}_t/v^2\ll s/v^2$) the one-loop amplitudes $W^{+}{W}^{-}\to t\bar{t}$, $ZZ\to t\bar{t}$ and $hh\to t\bar{t}$ (to NLO in the effective theory). We calculate the scalar partial-wave helicity amplitudes which allow us to check unitarity at the perturbative level in both $M_t/v$ and $s/v$. As with growing energy perturbative unitarity deteriorates, we also introduce a new unitarization method with the right analytical behavior on the complex $s$-plane and that can support poles on the second Riemann sheet to describe resonances in terms of the Lagrangian couplings. Thus we have achieved a consistent phenomenological description of any resonant $t\bar{t}$ production that may be enhanced by a possible strongly interacting Electroweak Symmetry Breaking Sector.

13 pages, 12 figures

References in corpus (7)

• Observation of a new particle in the search for the Standard Model Higgs boson with the ATLAS detector at the LHC
• Observation of a new boson at a mass of 125 GeV with the CMS experiment at the LHC
• Top-pair production at the LHC through NNLO QCD and NLO EW
• Signal background interference effects in heavy scalar production and decay to a top-anti-top pair
• Unitarity, analyticity, dispersion relations and resonances in strongly interacting $W_L{W}_L$, $Z_L{Z}_L$ and $hh$ scattering
• Search for the Standard Model Higgs boson decaying into $b\bar{b}$ produced in association with top quarks decaying hadronically in $pp$ collisions at $\sqrt{s}$=8 TeV with the ATLAS detector
• Possible new resonance from $W_L{W}_L$-$hh$ interchannel coupling

Cited by in corpus (6)

• The Standard Model as an Effective Field Theory
• SMEFT is falsifiable through multi-Higgs measurements (even in the absence of new light particles)
• Systematizing and addressing theory uncertainties of unitarization with the Inverse Amplitude Method
• Strongly coupled theories beyond the Standard Model
• SMEFT as a slice of HEFT's parameter space
• Resonant production of Wh and Zh at the LHC