168 research outputs found
Isolated-photon production in polarized hadronic collisions
After a short discussion on the definition of isolated-photon cross sections
in perturbative QCD, I present phenomenological predictions relevant for
polarized hadron-hadron collisions in the RHIC energy range. The possibility of
measuring is investigated.Comment: 3 pages Latex; npb.sty and 2 ps figures included. Talk given at
DIS99, 19 - 23 April 1999, Zeuthen, D
Isolated photons in perturbative QCD
I present a definition of the cross section for the production of an isolated
photon plus jets which only depends upon direct photon production, and it
is independent of the parton-to-photon fragmentation contribution. This
prescription, based on a modified cone approach which implements the isolation
condition in a smooth way, treats in the same way quarks and gluons and can be
directly applied to experimental data in hadron-hadron, photon-hadron and
\epem collisions. The case of several, isolated photons in the final state
can also be dealt with in the very same way.Comment: 10 pages Late
Determination of the top quark mass from leptonic observables
We present a procedure for the determination of the mass of the top quark at
the LHC based on leptonic observables in dilepton events. Our
approach utilises the shapes of kinematic distributions through their few
lowest Mellin moments; it is notable for its minimal sensitivity to the
modelling of long-distance effects, for not requiring the reconstruction of top
quarks, and for having a competitive precision, with theory errors on the
extracted top mass of the order of 0.8 GeV. A novel aspect of our work is the
study of theoretical biases that might influence in a dramatic way the
determination of the top mass, and which are potentially relevant to all
template-based methods. We propose a comprehensive strategy that helps minimise
the impact of such biases, and leads to a reliable top mass extraction at
hadron colliders.Comment: 29 pages, 3 figure
The MC@NLO 2.2 Event Generator
This is the user's manual of MC@NLO 2.2. This package is a practical
implementation, based upon the HERWIG event generator, of the MC@NLO formalism,
which allows one to incorporate NLO QCD matrix elements consistently into a
parton shower framework. Processes available in this version include the
hadroproduction of Higgs bosons, single vector bosons, vector boson pairs, and
heavy quark-antiquark pairs. This document is self-contained, but we emphasise
the main differences with respect to previous versions.Comment: 17 pages, no figures. Version 2 has more details on some features.
Program available at http://www.hep.phy.cam.ac.uk/theory/webber/MCatNLO
The MC@NLO 3.4 Event Generator
This is the user's manual of MC@NLO 3.4. This package is a practical
implementation, based upon the HERWIG event generator, of the MC@NLO formalism,
which allows one to incorporate NLO QCD matrix elements consistently into a
parton shower framework. Processes available in this version include the
hadroproduction of single vector and Higgs bosons, vector boson pairs, heavy
quark pairs, single top, single top in association with a W, lepton pairs, and
Higgs bosons in association with a W or Z. Spin correlations are included for
all processes except ZZ and WZ production. This document is self-contained, but
we emphasise the main differences with respect to previous versions.Comment: 30 page
D* Production in Two-Photon Collisions
We calculate total and differential production rates of D* mesons in
two-photon collisions at LEP2. We include full next-to-leading order QCD
corrections, and perform an extensive study of the sensitivity of our
predictions to variations of the renormalization scale, charm mass, photonic
parton distribution set and fragmentation function. The results are compared
with recent data from LEP2.Comment: Latex, 19 pages, 9 figure
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