848 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
Discovery limits for a new contact interaction at future hadronic colliders with polarized beams
The production of high-transverse energy jets in hadron-hadroncollisions is
sensitive to the presence of new contact interactions between quarks. If proton
polarization were available, the measurement of some parity violating spin
asymmetries in one-jet production at large transverse energy would complement
the usual search for deviations from the expected QCD cross section. In the
same time, a unique information on the chirality structure of the new
interaction could be obtained. In this context, we compare the potentialities
of various and colliders that are planned or have been proposed,
with the additional requirement of beam polarization.Comment: Latex file, 9 pages and 1 ps fig, definition of the subprocess
variables and one example of the effect of new contact terms on the parity
violating spin asymmetry are added. Eq. 8 (now eq. 9) and the following
equation are changed, giving better bounds in the polarized pp case (new
figure
Proposal of Qualitative Determination of Taxus baccata L. Homeopathic Tincture by applying Rapid Horizontal TLC and LC/MS Procedures
production at hadron colliders in NNLO QCD
Charged gauge boson pair production at the Large Hadron Collider allows
detailed probes of the fundamental structure of electroweak interactions. We
present precise theoretical predictions for on-shell production that
include, for the first time, QCD effects up to next-to-next-to-leading order in
perturbation theory. As compared to next-to-leading order, the inclusive
cross section is enhanced by 9% at 7 TeV and 12% at 14 TeV. The
residual perturbative uncertainty is at the 3% level. The severe contamination
of the cross section due to top-quark resonances is discussed in
detail. Comparing different definitions of top-free production in the
four and five flavour number schemes, we demonstrate that top-quark resonances
can be separated from the inclusive cross section without significant
loss of theoretical precision.Comment: 7 pages, 3 figure
Key exchange with the help of a public ledger
Blockchains and other public ledger structures promise a new way to create
globally consistent event logs and other records. We make use of this
consistency property to detect and prevent man-in-the-middle attacks in a key
exchange such as Diffie-Hellman or ECDH. Essentially, the MitM attack creates
an inconsistency in the world views of the two honest parties, and they can
detect it with the help of the ledger. Thus, there is no need for prior
knowledge or trusted third parties apart from the distributed ledger. To
prevent impersonation attacks, we require user interaction. It appears that, in
some applications, the required user interaction is reduced in comparison to
other user-assisted key-exchange protocols
W boson production at hadron colliders: the lepton charge asymmetry in NNLO QCD
We consider the production of W bosons in hadron collisions, and the
subsequent leptonic decay W->lnu_l. We study the asymmetry between the rapidity
distributions of the charged leptons, and we present its computation up to the
next-to-next-to-leading order (NNLO) in QCD perturbation theory. Our
calculation includes the dependence on the lepton kinematical cuts that are
necessarily applied to select W-> lnu_l events in actual experimental analyses
at hadron colliders. We illustrate the main differences between the W and
lepton charge asymmetry, and we discuss their physical origin and the effect of
the QCD radiative corrections. We show detailed numerical results on the charge
asymmetry in ppbar collisions at the Tevatron, and we discuss the comparison
with some of the available data. Some illustrative results on the lepton charge
asymmetry in pp collisions at LHC energies are presented.Comment: 37 pages, 21 figure
Improvement of Thermal Processes for Using Residues from Bioethanol and Sugar Production in Brazil: Experiments and Proposed Optimization Measures
Within a national funded Brazilian-German cooperation project ASHES, the thermal utilization of bagasse and other residuals from the sugar processing industry was examined. The characterization of the ashes was also performed but it is not in the focus of this paper. To determine the relevant combustion parameters, tests were carried out in a laboratory-scale, fixed bed reactor (KLEAA) at KIT-ITC. Subsequently, Fraunhofer UMSICHT carried out tests in continuously operated combustion plants with different plant sizes of 30 kW, 100 kW, and 440 kW. All relevant compositions were analyzed by CUTEC. The primary objective was to gain knowledge regarding the combustion and emission behavior of the fuels. These findings were used to identify optimization potentials at various points and elaborate concepts for their improvement. In the next steps of the project, optimization of these concepts will be the focus. In cooperation with the Brazilian project partners, several of them should be implemented into practice after the project
The fully differential hadronic production of a Higgs boson via bottom quark fusion at NNLO
The fully differential computation of the hadronic production cross section
of a Higgs boson via bottom quarks is presented at NNLO in QCD. Several
differential distributions with their corresponding scale uncertainties are
presented for the 8 TeV LHC. This is the first application of the method of
non-linear mappings for NNLO differential calculations at hadron colliders.Comment: 27 pages, 13 figures, 1 lego plo
Precision Calculations for Future Colliders
I discuss the motivations for, and the status of, precision calculations for
the Large Hadron Collider (LHC) and the planned International Linear Collider
(ILC).Comment: latex, uses ws-ijmpe.cls, 19 pages, 9 figures, 1 table, based on a
talk given at the symposium "50 Years of High Energy Physics at UB", to
appear in International Journal of Modern Physics
Security by Spatial Reference:Using Relative Positioning to Authenticate Devices for Spontaneous Interaction
Spontaneous interaction is a desirable characteristic associated with mobile and ubiquitous computing. The aim is to enable users to connect their personal devices with devices encountered in their environment in order to take advantage of interaction opportunities in accordance with their situation. However, it is difficult to secure spontaneous interaction as this requires authentication of the encountered device, in the absence of any prior knowledge of the device. In this paper we present a method for establishing and securing spontaneous interactions on the basis of emphspatial references that capture the spatial relationship of the involved devices. Spatial references are obtained by accurate sensing of relative device positions, presented to the user for initiation of interactions, and used in a peer authentication protocol that exploits a novel mechanism for message transfer over ultrasound to ensures spatial authenticity of the sender
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