412 research outputs found
Sudakov Logarithm Resummation for Vector Boson Production at Hadron Colliders
A complete description of W and Z boson production at high-energy colliders
requires the resummation of large Sudakov logarithms which dominate the
production at small transverse momentum. Currently there are two techniques for
performing this resummation: impact parameter space and transverse momentum
space. We argue that the latter can be formulated in a way which retains the
advantages of the former, while at the same time allowing a smooth transition
to finite order dominance at high transverse momentum.Comment: 5 pages, LaTeX, 2 figures, epsfig, contribution to the proceedings of
the UK Phenomenology Workshop on Collider Physics, 19-24 September 1999,
Durham, to be published in J. Phys.
The resummed Higgs boson transverse momentum distribution at the LHC
We apply QCD resummation techniques to study the transverse momentum
distribution of Higgs bosons produced via gluon-gluon fusion at the LHC. In
particular we focus on the joint resummation formalism which resums both
threshold and transverse momentum corrections simultaneously. A comparison of
results obtained in the joint and the standard recoil resummation frameworks is
presented.Comment: 9 pages, 1 figure, uses appolb.cls. Contribution to the Proceedings
of XXVII International Conference of Theoretical Physics, Ustron, Poland,
September 15-21, 2003. To appear in Acta Physica Polonica
Electroweak vector boson production in joint resummation
We study the application of the joint resummation to electroweak boson
production at hadron colliders. The joint resummation formalism resums both
threshold and transverse momentum corrections to the transverse momentum
distribution at next-to-leading logarithmic accuracy. We obtain a good
description of the transverse momentum distribution of Z bosons produced at the
Tevatron collider.Comment: 5 pages, 2 figures. Talk presented by A. Kulesza at the XXXVIIth
Rencontres de Moriond `QCD and high energy hadronic interactions', Les Arcs,
Franc
Prospects for observation of double parton scattering with four-muon final states at LHCb
We study the prospects for observing double parton scattering through
four-muon final states, forming two opposite-sign muon pairs, in the LHCb
experiment in pp collisions at 14 TeV centre of mass energy. We consider two
special cases, namely double Drell-Yan and J/psi-pair production. The kinematic
properties and prospects for observing these processes are discussed. We find
that the production rate depends strongly on the origin of the four muons,
while many kinematic properties can be used to help identify the presence of
double parton scattering events.Comment: 22 pages, 12 figure
Non-perturbative effects and the resummed Higgs transverse momentum distribution at the LHC
We investigate the form of the non-perturbative parameterization in both the
impact parameter (b) space and transverse momentum (p_T) space resummation
formalisms for the transverse momentum distribution of single massive bosons
produced at hadron colliders. We propose to analyse data on Upsilon
hadroproduction as a means of studying the non-perturbative contribution in
processes with two gluons in the initial state. We also discuss the theoretical
errors on the resummed Higgs transverse momentum distribution at the LHC
arising from the non-perturbative contribution.Comment: 22 pages, 10 figure
Supersymmetric top and bottom squark production at hadron colliders
The scalar partners of top and bottom quarks are expected to be the lightest
squarks in supersymmetric theories, with potentially large cross sections at
hadron colliders. We present predictions for the production of top and bottom
squarks at the Tevatron and the LHC, including next-to-leading order
corrections in supersymmetric QCD and the resummation of soft gluon emission at
next-to-leading-logarithmic accuracy. We discuss the impact of the higher-order
corrections on total cross sections and transverse-momentum distributions, and
provide an estimate of the theoretical uncertainty due to scale variation and
the parton distribution functions.Comment: 29 pages, 6 figure
Same-sign W pair production as a probe of double parton scattering at the LHC
We study the production of same-sign W boson pairs at the LHC in double
parton interactions. Compared with simple factorised double parton
distributions (dPDFs), we show that the recently developed dPDFs, GS09, lead to
non-trivial kinematic correlations between the W bosons. A numerical study of
the prospects for observing this process using same-sign dilepton signatures,
including same-sign WWjj, di-boson and heavy flavour backgrounds, at 14 TeV
centre-of-mass energy is then performed. It is shown that a small excess of
same-sign dilepton events from double parton scattering over a background
dominated by single scattering WZ(gamma*) production could be observed at the
LHC.Comment: 14 pages, 8 figures. Added references, slight changes in the text
Recommended from our members
Explanatory debugging: Supporting end-user debugging of machine-learned programs
Many machine-learning algorithms learn rules of behavior from individual end users, such as task-oriented desktop organizers and handwriting recognizers. These rules form a “program” that tells the computer what to do when future inputs arrive. Little research has explored how an end user can debug these programs when they make mistakes. We present our progress toward enabling end users to debug these learned programs via a Natural Programming methodology. We began with a formative study exploring how users reason about and correct a text-classification program. From the results, we derived and prototyped a concept based on “explanatory debugging”, then empirically evaluated it. Our results contribute methods for exposing a learned program's logic to end users and for eliciting user corrections to improve the program's predictions
- …