7,342 research outputs found
Next-to-leading order QCD corrections to photon production via weak-boson fusion
We present a calculation of next-to-leading order QCD corrections to gamma jj
production via weak-boson fusion at a hadron collider in the form of a flexible
parton-level Monte Carlo program which allows us to study cross sections and
distributions within experimentally relevant selection cuts. The radiative
corrections are found to be moderate with residual scale uncertainties being
considerably improved beyond tree level. The sensitivity of the reaction to
anomalous W+ W- gamma couplings is investigated.Comment: 14 pages, 8 figure
Next-to-leading order QCD corrections to W+Z and W-Z production via vector-boson fusion
We present the calculation of the next-to-leading order QCD corrections to
electroweak p p -> e+ nu_e mu+ mu- jj and p p -> e- nubar_e mu+ mu- jj
production at the CERN LHC in the form of a fully flexible parton-level Monte
Carlo program. The QCD corrections to the total cross sections are modest,
changing the leading-order results by less than 10%. At the Born level, the
shape of kinematic distributions can depend significantly on the choice of
factorization scale. This theoretical uncertainty is strongly reduced by the
inclusion of the next-to-leading order QCD corrections.Comment: 15 pages, 6 figures; new figure and comments added; version published
by PR
Next-to-leading order QCD corrections to high-p_T pion production in longitudinally polarized pp collisions
We present a calculation for single-inclusive large-p_T pion production in
longitudinally polarized pp collisions in next-to-leading order QCD. We choose
an approach where fully analytical expressions for the underlying partonic
hard-scattering cross sections are obtained. We simultaneously rederive the
corresponding corrections to unpolarized scattering and confirm the results
existing in the literature. Our results allow to calculate the double-spin
asymmetry A_LL^pi for this process at next-to-leading order, which will soon be
used at BNL-RHIC to measure the polarization of gluons in the nucleon.Comment: 23 pages, LaTeX, 6 figures as eps file
Parton-shower effects on Higgs boson production via vector-boson fusion in association with three jets
We present an implementation of Higgs boson production via vector-boson
fusion in association with three jets at hadron colliders in the POWHEG-BOX, a
framework for the matching of NLO-QCD calculations with parton-shower programs.
Our work provides the means to precisely describe the properties of extra jet
activity in vector-boson fusion reactions that are used for the suppression of
QCD backgrounds by central jet veto techniques. For a representative setup at
the CERN LHC we verify that uncertainties related to parton-shower effects are
mild for distributions related to the third jet, in contrast to what has been
observed in calculations based on vector-boson fusion induced Higgs production
in association with two jets.Comment: 12 pages, 8 figure
The Super Bigbite Project: a Study of Nucleon Form Factors
A proposed set of instrumentation, collectively referred to as the Super
Bigbite project, is presented. Used in three different configurations it will
allow measurements of three nucleon electromagnetic form factors GEn, GEp, and
GMn with unprecedented precision to Q2-values up to three times higher than
existing data
Flavor decomposition of the elastic nucleon electromagnetic form factors
The u- and d-quark contributions to the elastic nucleon electromagnetic form
factors have been determined using experimental data on GEn, GMn, GpE, and GpM.
Such a flavor separation of the form factors became possible up to 3.4 GeV2
with recent data on GEn from Hall A at JLab. At a negative four-momentum
transfer squared Q2 above 1 GeV2, for both the u- and d-quark components, the
ratio of the Pauli form factor to the Dirac form factor, F2/F1, was found to be
almost constant, and for each of F2 and F1 individually, the d-quark portions
of both form factors drop continuously with increasing Q2.Comment: 4 pages, 3 figure
Do methanethiol adsorbates on the Au(111) surface dissociate?
The interaction of methanethiol molecules CHSH with the Au(111) surface
is investigated, and it is found for the first time that the S-H bond remains
intact when the methanethiol molecules are adsorbed on the regular Au(111)
surface. However, it breaks if defects are present in the Au(111) surface. At
low coverage, the fcc region is favored for S atom adsorption, but at saturated
coverage the adsorption energies at various sites are almost iso-energetic. The
presented calculations show that a methanethiol layer on the regular Au(111)
surface does not dimerize.Comment: 4 pages, 2 figures, 4 tables, submitted to Phys. Rev. Let
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