637 research outputs found
Branching Fraction Measurements of the SM Higgs with a Mass of 160 GeV at Future Linear \ee Colliders
Assuming an integrated luminosity of 500 fb and a center-of-mass
energy of 350 GeV, we examine the prospects for measuring branching fractions
of a Standard Model-like Higgs boson with a mass of 160 GeV at the future
linear \ee collider TESLA when the Higgs is produced via the Higgsstrahlung
mechanism, \ee \pfr HZ. We study in detail the precisions achievable for the
branching fractions of the Higgs into WW, ZZ and \bb. However, the
measurement of BF(H \pfr \gaga) remains a great challence. Combined with the
expected error for the inclusive Higgsstrahlung production rate the uncertainty
for the total width of the Higgs is estimated.Comment: 17 pages Latex, including 7 figure
On the search for 50 GeV neutrinos
Using the computer code CompHEP we estimate the number of events and the
background, at LEP II and TESLA, for the reaction ,
where is a hypothetical Dirac neutrino with mass of the order of 50 GeV.Comment: Standard LaTeX, 9 pages, 2 tables, 3 figure
Precision measurements, extra generations and heavy neutrino
The existence of extra chiral generations with all fermions heavier than
is strongly disfavored by the precision electroweak data. The exclusion
of one additional generation of heavy fermions in SUSY extension of Standard
Model is less forbidden if chargino and neutralino have low degenerate masses
with GeV. However the data are fitted nicely even by a few
extra generations, if one allows neutral leptons to have masses close to 50
GeV. Such heavy neutrino can be searched in the reaction at LEP-200 with total final luminosity of .Comment: 5 pages, 6 figures, Proceedings ICHEP2000 Osaka conferenc
Higgs Boson Discovery Potential of LHC in the Channel
We discuss the SM Higgs discovery potential of LHC in the reaction when the jet is observed at sufficiently high to
be reliably identified. We conclude that this channel gives promising discovery
possibilities for the Higgs boson mass range 100-140 GeV, during LHC operation
at a low luminosity. With 30 fb of accumulated data and for
GeV about 100 signal events could be observed with the number of background
events larger by a factor of 2 only, showing a signal significance
. We use the difference of distributions in the partonic
subprocess energy for the signal and background for a better
separation of the signal.Comment: 15 pages including 6 figures, LaTeX, use epsfig.sty. To appear in
Phys.Lett.B. In this replacement minor LaTeX improvements are mad
Search for Higgs Boson at LHC in the Reaction pp->gamma+gamma+jet at a Low Luminosity
We discuss the SM Higgs discovery potential of the LHC in the channel
pp->H+jet->gamma+gamma+jet when the jet is observed at sufficiently high Pt and
a small rapidity to be reliably identified. We calculate all the signal
subprocesses and the irreducible background with realistic kinematical cuts.
The reducible QCD background is also estimated. We conclude that the channel
gamma+gamma+jet can give about 120-200 signal events for Higgs mass MH=100-140
GeV at the integrated luminosity of 30 inverse fb. This signal rate should be
compared with only 330-600 events for the irreducible background per two-photon
invariant mass interval of 2 GeV. We estimate the QCD reducible background at
the level of 20% of the irreducible one. Thus, one may hope that the Higgs
boson can be discovered already during the LHC operation at a low luminosity.
At a high luminosity the observation of several hundreds of high Pt Higgs
bosons in this channel will be possible with significance higher than 15 for
L=100 inverse fb.Comment: 21 pages (LaTeX code, epsf.sty), 2 tables, 9 figures; to appear in
the Proceedings of XIIth International Workshop on High Energy Physics and
Quantum Field Theory (QFTHEP-97), Samara, Russia, September 4-10, 199
The application of Signal Detection Theory principles to aircraft certification
This paper presents the application of Signal Detection Theory (SDT) concepts to the certification of optional systems that provide operational or system safety benefits. The method and analysis yield quantitative requirements for the system performance that account for the risks and benefits of the potential system. This is in contrast to the standard certification approach which only focuses on Failure Conditions, and does not examine potential system benefits. A case study of an aircraft spotter on an electronic moving map illustrates that substantial safety improvements may be achieved even with the relatively low levels of software reliability associated with Commercial Off-the-shelf Software (COTS). The method makes few domain assumptions, and is based on the underpinnings of SDT and Bayesian probability theory, with well-established validity and reliability. Accordingly, the technique should have broad application to the certification of all optional aircraft systems
Age features of O2 mass transfer regimes in adolescents’ body at rest
The results of complex studies of the quantitative relationship between the stage-by-stage mass transfer of O2 and the efficiency of cardiorespiratory system functioning in relation to its consumption in adolescents’ body under conditions of relative rest are presented.
The results obtained show that in adolescents, the modes of mass transfer of O2 in the body and the nature of the respiratory and circulatory systems functioning in relation to its consumption have a number of age-related differences compared with adult men. So, in adolescents, the external respiration system at rest functions less economically than in adults. Each liter of O2 consumed by adolescents is extracted from almost 3 liters more than in adults the amount of air ventilated per minute through the lungs. The volumetric indicators of blood circulation are also higher in adolescents, which may indicate the influence of neuro-humoral rearrangements in the body during the pubertal period. The coefficient of oxygen utilization by tissues from arterial blood in adolescents turned out to be significantly higher, which may characterize a higher tension of tissue metabolic processes
Mass of the higgs versus fourth generation masses
The predicted value of the higgs mass is analyzed assuming the
existence of the fourth generation of leptons () and quarks ().
The steep and flat directions are found in the five-dimensional parameter
space: , , , , . The LEPTOP fit of the precision
electroweak data is compatible (in particular) with GeV, GeV, GeV, GeV, and GeV. The quality of fits drastically improves when the data on b- and
c-quark asymmetries and new NuTeV data on deep inelastic scattering are
ignored.Comment: 8 pages, 4 figure
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