35 research outputs found
Vector boson production in joint resummation
We study the transverse momentum () distribution of an electro-weak
vector boson produced via the Drell-Yan mechanism, in the context of joint
resummation. This formalism allows for the simultaneous resummation of
logarithmic contributions that are enhanced at small and at partonic
threshold. We extend joint resummation to next-to-next-to leading logarithmic
accuracy and we present resummed and matched results for three different
phenomenological setups. In particular, we study the production of a boson
at the Tevatron and at the Large Hadron Collider (LHC), as well as the
production of a heavier at the LHC. We compare our findings to
standard resummation, as well as to fixed-order perturbation theory. We
find that joint resummation provides a moderate (but not flat) correction with
respect to resummation and it leads to a reduction of the scale
dependence of the results. However, our study also shows some limitations of
this formalism. While the use of joint resummation for production at the
Tevatron and production at the LHC appears to be justified, our
implementation suffers from a stronger dependence on power corrections for
processes which are further away from threshold, such as production at the
LHC, for which we cannot claim an improvement over standard resummation.Comment: 28 pages, 10 figures, published versio
Soft gluon resummation for associated production at the LHC
We perform resummation of soft gluon corrections to the total cross section
for the process . The resummation is carried out at
next-to-leading-logarithmic (NLL) accuracy using the Mellin space technique,
extending its application to the class of processes. We present an
analytical result for the soft anomalous dimension for a hadronic production of
two coloured massive particles in association with a colour singlet. We discuss
the impact of resummation on the numerical prediction for the associated Higgs
boson production with top quarks at the LHC.Comment: 11 pages, 4 figure
Improving predictions for associated production at the LHC : soft gluon resummation through NNLL accuracy
In the following we present our recent results on the resummation of soft
gluon corrections to the cross section at the LHC.
The resummation was carried out at next-to-next-to-leading-logarithmic (NNLL)
accuracy using the Mellin space technique. Obtained results were matched to the
NLO cross section. We show that the resummation leads to reduction of
scale-variation uncertainty of the total cross
section.Comment: 6 pages, 1 figure, 1 table, proceedings prepared for the European
Physical Society Conference on High Energy Physics (EPS-HEP 2017), 5-12 July
2017, Venice, Ital
Associated production at the LHC: theoretical predictions at NLO+NNLL accuracy
We perform threshold resummation of soft gluon corrections to the total cross
section and the invariant mass distribution for the process .
The resummation is carried out at next-to-next-to-leading-logarithmic (NNLL)
accuracy using the direct QCD Mellin space technique in the three-particle
invariant mass kinematics. After presenting analytical expressions we discuss
the impact of resummation on the numerical predictions for the associated Higgs
boson production with top quarks at the LHC. We find that NLO+NNLL resummation
leads to predictions for which the central values are remarkably stable with
respect to scale variation and for which theoretical uncertainties are reduced
in comparison to NLO predictions.Comment: 21 pages, 9 figures; NNLL results accounting now for color
decomposition of the one-loop hard function, discussion of the literature
added, typos correcte
Soft gluon resummation for gluon-induced Higgs Strahlung
We study the effect of soft gluon emission on the total cross section
predictions for the associated Higgs production process at the LHC.
To this end, we perform resummation of threshold corrections at the NLL
accuracy in the absolute threshold production limit and in the threshold limit
for production of a system with a given invariant mass. Analytical results
and numerical predictions for various possible LHC collision energies are
presented. The perturbative stability of the results is verified by including
universal NNLL effects. We find that resummation significantly reduces the
scale uncertainty of the contribution, which is the dominant source
of perturbative uncertainty to production. We use our results to evaluate
updated numbers for the total inclusive cross section of associated
production at the LHC. The reduced scale uncertainty of the
component translates into a decrease of the overall scale error by about a
factor of two.Comment: 22 pages, 4 figures, 2 table
Soft gluon resummation for the associated production of a top quark pair with a W boson at the LHC
We present our results on soft gluon resummation in the invariant mass
threshold applied to the associated production of a top quark pair with a W
boson at the LHC in the Mellin space formalism.Comment: 6 pages, 4 figures, 1 table, proceedings prepared for the European
Physical Society Conference on High Energy Physics (EPS-HEP 2017), 5-12 July
2017, Venice, Ital
Associated top-pair production with a heavy boson production through NLO+NNLL accuracy at the LHC
In this talk we present results of our recent calculations of cross sections
and distributions for the associate production of top-antitop quark pairs with
a heavy boson (Higgs, W, Z) at the LHC, obtained using threshold resummation in
direct QCD, i.e. in the Mellin-space approach.Comment: 4 pages, 6 figures, contribution to the 2019 QCD session of the 54th
Rencontres de Morion
Associated top quark pair production with a heavy boson: differential cross sections at NLO+NNLL accuracy
We present theoretical predictions for selected differential cross sections
for the process at the LHC, where can be a Higgs
(), a or a boson. The predictions are calculated in the direct QCD
framework up to the next-to-next-leading logarithmic (NNLL) accuracy and
matched to the complete NLO results including QCD and electroweak effects.
Additionally, results for the total cross sections are provided. The
calculations deliver a significant improvement of the theoretical predictions,
especially for the and the production. In these
cases, predictions for both the total and differential cross sections are
remarkably stable with respect to the central scale choice and carry a
substantially reduced scale uncertainty in comparison with the complete NLO
predictions.Comment: 28 pages, 23 figures; Published versio
Top Precision for Associated Top-Pair Production Processes at the LHC
The studies of the associated production processes of a top-quark pair with a
colour-singlet boson, e.g. Higgs, W or Z, are among the highest priorities of
the LHC programme. Correspondingly, improvements in precision of theoretical
predictions for these processes are of central importance. In this talk, we
review our latest results on resummation of soft gluon corrections. The
resummation is carried out using the direct QCD Mellin space technique in
three-particle invariant mass kinematics. We discuss the impact of the soft
gluon corrections on predictions for total cross sections and differential
distributions.Comment: 12 pages, 9 figures, proceedings of the XXVI Cracow Epiphany
Conference on LHC Physics: Standard Model and Beyond, to be published in Acta
Physica Polonica