32,868 research outputs found
A phenomenological interpretation of open charm production at HERA in terms of the semi-hard approach
In the framework of the semi-hard (k_t-factorization) approach, we analyze
the various charm production processes in the kinematic region covered by the
HERA experiments.Comment: DESY 02-017, LUNFD6/(NFFL--7209) 200
Unintegrated gluon distribution and soft pp collisions at LHC
We found the parameterization of the unintegrated gluon distribution from the
best description of the LHC data on the inclusive spectra of hadrons produced
in collisions at the mid-rapidity region and small transverse momenta. It
is different from the one obtained within perturbative QCD only at low
intrinsic transverse momenta . The application of this distribution to
analysis of the DIS allows us to get the results which do not contradict
the H1 and ZEUS data on the structure functions at low . So, the connection
between the soft processes at LHC and low- physics at HERA is found.Comment: 8 pages, 4 figures. Contributed to 3rd Workshop on Multi-Parton
Interactions at the LHC (MPI11), Hamburg, 21-25 November 201
Determination of HART I Blade Structural Properties by Laboratory Testing
The structural properties of higher harmonic Aeroacoustic Rotor Test (HART I) blades were measured using the original set of blades tested in the German-dutch wind tunnel (DNW) in 1994. the measurements include bending and torsion stiffness, geometric offsets, and mass and inertia properties of the blade. the measured properties were compared to the estimated values obtained initially from the blade manufacturer. The previously estimated blade properties showed consistently higher stiffness, up to 30 percent for the flap bending in the blade inboard root section
Investigation of beauty production and parton shower effects at LHC
We present hadron-level predictions from the Monte Carlo generator Cascade
and parton level calculations of open b quark, b-flavored hadron and inclusive
b-jet production in the framework of the kt-factorization QCD approach for the
LHC energies. The unintegrated gluon densities in a proton are determined using
the CCFM evolution equation and the Kimber-Martin-Ryskin (KMR) prescription.
Our predictions are compared with the first data taken by the CMS and LHCb
collaborations at 7 TeV. We study the theoretical uncertainties of our
calculations and investigate the effects coming from parton showers in initial
and final states. The special role of initial gluon transverse momenta in
description of the data is pointed out.Comment: 19 pages, 11 figures. arXiv admin note: substantial text overlap with
arXiv:1105.507
Tripartite Entanglement in Noninertial Frame
The tripartite entanglement is examined when one of the three parties moves
with a uniform acceleration with respect to other parties. As Unruh effect
indicates, the tripartite entanglement exhibits a decreasing behavior with
increasing the acceleration. Unlike the bipartite entanglement, however, the
tripartite entanglement does not completely vanish in the infinite acceleration
limit. If the three parties, for example, share the Greenberger-Horne-Zeilinger
or W-state initially, the corresponding -tangle, one of the measures for
tripartite entanglement, is shown to be or 0.176 in this
limit, respectively. This fact indicates that the tripartite quantum
information processing may be possible even if one of the parties approaches to
the Rindler horizon. The physical implications of this striking result are
discussed in the context of black hole physics.Comment: 19 pages, 5 figure
Superperturbation solver for quantum impurity models
We present a very efficient solver for the general Anderson impurity problem.
It is based on the perturbation around a solution obtained from exact
diagonalization using a small number of bath sites. We formulate a perturbation
theory which is valid for both weak and strong coupling and interpolates
between these limits. Good agreement with numerically exact quantum Monte-Carlo
results is found for a single bath site over a wide range of parameters. In
particular, the Kondo resonance in the intermediate coupling regime is well
reproduced for a single bath site and the lowest order correction. The method
is particularly suited for low temperatures and alleviates analytical
continuation of imaginary time data due to the absence of statistical noise
compared to quantum Monte-Carlo impurity solvers.Comment: 6 pages, 5 figure
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