12,622 research outputs found
Monte Carlo study of gg->H+jets contribution to Vector Boson Fusion Higgs production at the LHC
The contribution of gg->H+jets production process to the vector boson fusion
production of the Higgs boson, VV->H, at LHC was evaluated with the ALPGEN
generator and the PYTHIA shower Monte Carlo including a jet-parton matching
procedure. After the experimental like event selections applied at PYTHIA
particle level, the contribution was found to be 4-5 % for a Higgs boson mass
of 120 GeV
Viscous Effects in the Inception of Cavitation on Axisymmetric Bodies
Cavitation inception and development on two axisymmetric bodies was studied with the aid of a Schlieren flow visualization method developed for that purpose. Both bodies were found to exhibit a laminar boundary layer separation; cavitation inception was observed to occur within this region of separated flow. The incipient cavitation index was found to be closely correlated with the magnitude of the pressure coefficient at the location of flow separation on one of the bodies. There is also experimental evidence that events at the site of turbulent reattachment of the separated flow may also greatly influence cavitation inception
Recursive image sequence segmentation by hierarchical models
This paper addresses the problem of image sequence segmentation. A technique using a sequence model based on compound random fields is presented. This technique is recursive in the sense that frames are processed in the same cadency as they are produced. New regions appearing in the sequence are detected by a morphological procedure.Peer ReviewedPostprint (published version
Bosonic and fermionic Weinberg-Joos (j,0)+ (0,j) states of arbitrary spins as Lorentz-tensors or tensor-spinors and second order theory
We propose a general method for the description of arbitrary single spin-j
states transforming according to (j,0)+(0,j) carrier spaces of the Lorentz
algebra in terms of Lorentz-tensors for bosons, and tensor-spinors for
fermions, and by means of second order Lagrangians. The method allows to avoid
the cumbersome matrix calculus and higher \partial^{2j} order wave equations
inherent to the Weinberg-Joos approach. We start with reducible Lorentz-tensor
(tensor-spinor) representation spaces hosting one sole (j,0)+(0,j) irreducible
sector and design there a representation reduction algorithm based on one of
the Casimir invariants of the Lorentz algebra. This algorithm allows us to
separate neatly the pure spin-j sector of interest from the rest, while
preserving the separate Lorentz- and Dirac indexes. However, the Lorentz
invariants are momentum independent and do not provide wave equations. Genuine
wave equations are obtained by conditioning the Lorentz-tensors under
consideration to satisfy the Klein-Gordon equation. In so doing, one always
ends up with wave equations and associated Lagrangians that are second order in
the momenta. Specifically, a spin-3/2 particle transforming as (3/2,0)+ (0,3/2)
is comfortably described by a second order Lagrangian in the basis of the
totally antisymmetric Lorentz tensor-spinor of second rank, \Psi_[ \mu\nu].
Moreover, the particle is shown to propagate causally within an electromagnetic
background. In our study of (3/2,0)+(0,3/2) as part of \Psi_[\mu\nu] we
reproduce the electromagnetic multipole moments known from the Weinberg-Joos
theory. We also find a Compton differential cross section that satisfies
unitarity in forward direction. The suggested tensor calculus presents itself
very computer friendly with respect to the symbolic software FeynCalc.Comment: LaTex 34 pages, 1 table, 8 figures. arXiv admin note: text overlap
with arXiv:1312.581
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