32 research outputs found
Antenna subtraction with massive fermions at NNLO: Double real initial-final configurations
We derive the integrated forms of specific initial-final tree-level
four-parton antenna functions involving a massless initial-state parton and a
massive final-state fermion as hard radiators. These antennae are needed in the
subtraction terms required to evaluate the double real corrections to
hadronic production at the NNLO level stemming from the partonic
processes and .Comment: 24 pages, 1 figure, 1 Mathematica file attache
NNLO corrections to top-pair production at hadron colliders: the all-fermionic scattering channels
This is a second paper in our ongoing calculation of the
next-to-next-to-leading order (NNLO) QCD correction to the total inclusive
top-pair production cross-section at hadron colliders. In this paper we
calculate the reaction which was not considered
in our previous work on due to its phenomenologically
negligible size. We also calculate all remaining fermion-pair-initiated
partonic channels and that contribute to top-pair
production starting from NNLO. The contributions of these reactions to the
total cross-section for top-pair production at the Tevatron and LHC are small,
at the permil level. The most interesting feature of these reactions is their
characteristic logarithmic rise in the high energy limit. We compute the
constant term in the leading power behavior in this limit, and achieve
precision that is an order of magnitude better than the precision of a recent
theoretical prediction for this constant. All four partonic reactions computed
in this paper are included in our numerical program Top++. The calculation of
the NNLO corrections to the two remaining partonic reactions,
and , is ongoing.Comment: 1+16 pages; 3 figure
Antenna subtraction at NNLO with hadronic initial states: double real initial-initial configurations
The antenna subtraction method handles real radiation contributions in higher
order corrections to jet observables. The method is based on antenna functions,
which encapsulate all unresolved radiation between a pair of hard radiator
partons. To apply this method to compute hadron collider observables,
initial-initial antenna functions with both radiators in the initial state are
required in unintegrated and integrated forms. In view of extending the antenna
subtraction method to next-to-next-to-leading order (NNLO) calculations at
hadron colliders, we derive the full set of initial-initial double real
radiation antenna functions in integrated form.Comment: 38 pages; a FORM file with the integrated antennae is included with
this submission. arXiv admin note: text overlap with arXiv:1011.6631,
arXiv:1107.403
Antenna subtraction at NNLO with hadronic initial states: real-virtual initial-initial configurations
The antenna subtraction method handles real radiation contributions in higher
order corrections to jet observables. The method is based on antenna functions,
which encapsulate all unresolved radiation between a pair of hard radiator
partons. To apply this method to compute hadron collider observables,
initial-initial antenna functions with both radiators in the initial state are
required. In view of extending the antenna subtraction method to
next-to-next-to-leading order (NNLO) calculations at hadron colliders, we
derive the one-loop initial-initial antenna functions in unintegrated and
integrated form.Comment: 24 page