294 research outputs found
e+ e- -> t anti-t H including decays: on the size of background contributions
We present results for the lowest order cross sections, calculated with the
complete set of the standard model Feynman diagrams, of all possible detection
channels of the associated production of the top quark pair and the light Higgs
boson, which may be used for determination of the top-Higgs Yukawa coupling at
the future e+e- linear collider. We show that, for typical particle
identification cuts, the background contributions are large. In particular, the
QCD background contributions are much bigger than could be expected when taking
into account a possibly low virtuality of exchanged gluons. Moreover, we
include the initial state radiation effects and discuss the dependence of the
cross sections on the Higgs boson and top quark masses.Comment: 13 pages, 1 figure; substantially revised version, accepted for
publication in Eur.Phys.J.
Maximal subextensions of plurisubharmonic functions
In this paper we are concerned with the problem of local and global
subextensions of (quasi-)plurisubharmonic functions from a "regular" subdomain
of a compact K\"ahler manifold. We prove that a precise bound on the complex
Monge-Amp\`ere mass of the given function implies the existence of a
subextension to a bigger regular subdomain or to the whole compact manifold. In
some cases we show that the maximal subextension has a well defined complex
Monge-Amp\`ere measure and obtain precise estimates on this measure. Finally we
give an example of a plurisubharmonic function with a well defined
Monge-Amp\`ere measure and the right bound on its Monge-Amp\`ere mass on the
unit ball in \C^n for which the maximal subextension to the complex
projective space \mb P_n does not have a globally well defined complex
Monge-Amp\`ere measure
Factorizable electroweak one-loop corrections to top quark pair production and decay in e+e- collisions
We discuss an influence of the quantum electrodynamics corrections due to the initial state radiation in the structure function approach and factorizable electroweak O( ) corrections in the pole approximation on the
standard model predictions for top quark pair production and decay into six fermions at a linear e+e− collider. The discussion is illustrated with numerical results for one selected six-fermion reaction e+e− ! b μμ+¯ bμ−¯ μ
Production of Bc mesons in photon-photon and hadron-hadron collisions
We discuss two-photon and hadronic production of Bc mesons in nonrelativistic
bound state approximation and to lowest order in the coupling
constants a and a s . It is shown that in photon-photon collisions, heavy
quark fragmentation is dominated by recombination of b and c quarks up
to the highest accessible transverse momenta. In contrast, in hadroproduction,
which at high energies mainly involves gluon-gluon collisions, the
fragmentation mechanism dominates at transverse momenta py > mRc,
providing a simple and satisfactory approximation of the complete 0(a ) )
results in the high-px regime. Contradictions in previous publications
on hadroproduction of Bc mesons are clarified. We also present predictions
for cross sections and differential distributions at present and future
accelerators
Microstructured reactor as a pre-turbo catalytic converter
The idea of a structured catalytic converter
placed immediately after engine exhaust valves, thus
operating on high gas temperature and velocity, is
explored. The assumption is that major part of the reactor
operates in the entry region where Nusselt and Sherwood
numbers are highly enhanced. In this work, flow resistances
as well as heat and mass transfer coefficients were studied
for gas velocities exceeding 50 m/s. Consequently, the
transition range (between laminar and turbulent flows) was
reached. The comparison with classic monolith has shown
significant improvement in heat or mass transfer paid by
slight increase in flow resistance
Top quark pair production and decay at linear colliders: signal vs. off resonance background
Standard Model predictions for the reactions with six fermions in the final
state relevant for top quark pair production and decay at linear colliders are
discussed. An issue of the double resonance signal versus non doubly resonant
background is addresed. Effects related to the off-mass-shell production of the
t\bar{t}-pair are discussed.Comment: 9 pages, talk presented by K. Kolodziej at 6th International
Symposium on Radiative Corrections RADCOR 2002 and 6th Zeuthen Workshop on
Elementary Particle Theory ``Loops and Legs in Quantum Field Theory'',
Kloster Banz, Germany, September 8--13, 200
Towards high precision predictions for top quark pair production and decay at a linear collider
We report on the progress in work on improving precision of the standard model theoretical predictions for the top quark pair production and Decay into six fermions at a linear collider. Two programs have been combined
into a single Monte Carlo program: eett6f, a MC program for e+e− ! 6f, and topfit, a program for electroweak radiative corrections to e+e− ! t¯t. The MC program is described and preliminary numerical results are shown
ECOLOGICAL ENTREPRENEURSHIP IN WINE-PRODUCING MICRO-ENTERPRISES IN THE LOWER SILESIAN VOIVODESHIP
This article attempts to determine the conditions of ecological entrepreneurship in micro-enterprises producing wine in the Lower Silesian Voivodeship. Currently, the implementation of pro-environmental ideas in local enterprises is of great importance. This is particularly important for micro-entrepreneurs, whose share of GDP in this region is the highest in Poland. The wine industry is deserving of attention because the number of producers has increased greatly in recent years (including in the Lower Silesian Voivodship). In addition to a literature review, the article will present the results of the author’s own doctoral research on determining the conditions and manifestations of local entrepreneurship in the Lower Silesian Voivodship on the example of wine production
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