7 research outputs found
Exclusive top production at a Linear Collider at and off the threshold
We review exclusive top pair production including decays at a future
high-energy lepton collider, both in the threshold region and for higher
energies. For the continuum process, we take complete QCD next-to-leading order
matrix elements for the process with leptonic W decays into account.
At threshold, we match the fixed-order relativistic QCD-NLO cross section to a
nonrelativistic cross section with next-to-leading logarithmic (NLL) threshold
resummation implemented via a form factor.Comment: Talk presented at the International Workshop on Future Linear
Colliders (LCWS2017), Strasbourg, France, 23-27 October 2017. C17-10-23.
NLO QCD predictions for off-shell tt¯ and tt¯H production and decay at a linear collider
We present predictions for and production and decay
at future lepton colliders including non-resonant and interference
contributions up to next-to-leading order (NLO) in perturbative QCD. The
obtained precision predictions are necessary for a future precise determination
of the top-quark Yukawa coupling, and allow for top-quark phenomenology in the
continuum at an unprecedented level of accuracy. Simulations are performed with
the automated NLO Monte-Carlo framework WHIZARD interfaced to the OpenLoops
matrix element generator.Comment: 42 pages, 21 figure
NLO QCD Predictions for off-shell and Production and Decay at a Linear Collider
We present predictions for and production and decay at future lepton colliders including non-resonant and interference contributions up to next-to-leading order (NLO) in perturbative QCD. The obtained precision predictions are necessary for a future precise determination of the top-quark Yukawa coupling, and allow for top-quark phenomenology in the continuum at an unprecedented level of accuracy. Simulations are performed with the automated NLO Monte-Carlo framework WHIZARD interfaced to the OpenLoops matrix element generator
CONSORT flow diagram, showing inclusion and exclusion of participants in the study.
<p>CONSORT flow diagram, showing inclusion and exclusion of participants in the study.</p
Exclusive top production at a Linear Collider at and off the threshold
We review exclusive top pair production including decays at a future high-energy lepton collider, both in the threshold region and for higher energies. For the continuum process, we take complete QCD next-to-leading order matrix elements for the process with leptonic W decays into account. At threshold, we match the fixed-order relativistic QCD-NLO cross section to a nonrelativistic cross section with next-to-leading logarithmic (NLL) threshold resummation implemented via a form factor
Fully-differential top-pair production at a lepton collider: from threshold to continuum
We present an approach to predict exclusive W+bW−b¯¯ production at lepton colliders that correctly describes the top-anti-top threshold as well as the continuum region. We incorporate tt¯ form factors for the NLL threshold resummation derived in NRQCD into a factorized relativistic cross section using an extended double-pole approximation, which accounts for fixed-order QCD corrections to the top decays at NLO. This is combined with the full fixed-order QCD result at NLO for W+bW−b¯¯ production to obtain predictions that are not only valid at threshold but smoothly transition to the continuum region. Our implementation is based on the Monte Carlo event generator Whizard and the code Toppik and allows to compute fully-differential threshold-resummed cross sections including the interference with non-resonant background processes. For the first time it is now possible to systematically study general differential observables at future lepton colliders involving the decay products of the top quarks at energies close to the pair production threshold and beyond.© The Author