14,566 research outputs found
Searches for Low Mass Higgs Boson at the Tevatron
We present the result of the searches for a low mass Standard Model Higgs
boson performed at the Tevatron ppbar collider (sqrt(s) =1.96 TeV) by the CDF
and D0 experiments with an integrated luminosity of up to 8.5 fb^-1. Individual
searches are discussed and classified according to their sensitivity. Primary
channels rely on the associate production with a vector boson (WH or ZH) and
the H->bbbar decay channel (favored for M_H<135 GeV/c^2). Event selection is
based on the leptonic decay of the vector boson and the identification of
b-hadron enriched jets. Each individual channel is sensitive, for M_H=115
GeV/c^2, to less than 5 times the SM expected cross section and the most
sensitive channels can exclude a production cross section of 2.3 x sigma_H SM.
Secondary channels rely on a variety of final states. Although they are from 2
to 5 times less sensitive than any primary channel, they contribute to the
Tevatron combination and, in some cases, they pose strong constrains on exotic
Higgs boson models.Comment: Presented at the 2011 Hadron Collider Physics symposium (HCP-2011),
Paris, France, November 14-18 2011, 4 pages, 5 figur
Searches for electroweak production of supersymmetric gauginos and sleptons with the ATLAS detector
Many supersymmetry models feature gauginos and also sleptons with masses
below a few hundred GeV. These can give rise to direct pair production rates at
the LHC that can be observed in the data sample recorded by the ATLAS detector.
The talk presents results from searches for gaugino and slepton pair production
in final states with leptons.Comment: LHCP 2014 conference proceedin
Reachability problems for a wave-wave system with a memory term
We solve the reachability problem for a coupled wave-wave system with an integro-differential term. The control functions act on one side of the boundary. The estimates on the time is given in terms of the parameters of the problem and they are explicitly computed thanks to Ingham type results. Nevertheless some restrictions appear in our main results. The Hilbert Uniqueness Method is briefly recalled. Our findings can be applied to concrete examples in viscoelasticity theor
Inverse observability inequalities for integrodifferential equations in square domains
In this paper we will consider oscillations of square viscoelastic membranes by adding to the wave equation another term, which takes into account the memory. To this end, we will study a class of integrodifferential equations in square domains. By using accurate estimates of the spectral properties of the integrodifferential operator, we will prove an inverse observability inequality
Control problems for weakly coupled systems with memory
We investigate control problems for wave-Petrovsky coupled systems in the
presence of memory terms. By writing the solutions as Fourier series, we are
able to prove Ingham type estimates, and hence reachability results. Our
findings have applications in viscoelasticity theory and linear acoustic
theory
Support Vector Machine Classification on a Biased Training Set: Multi-Jet Background Rejection at Hadron Colliders
This paper describes an innovative way to optimize a multivariate classifier,
in particular a Support Vector Machine algorithm, on a problem characterized by
a biased training sample. This is possible thanks to the feedback of a
signal-background template fit performed on a validation sample and included
both in the optimization process and in the input variable selection. The
procedure is applied to a real case of interest at hadron collider experiments:
the reduction and the estimate of the multi-jet background in the
plus jets data sample collected by the CDF experiment. The training samples,
partially derived from data and partially from simulation, are described in
detail together with the input variables exploited for the classification. At
present, the reached performance is superior to any other prescription applied
to the same final state at hadron collider experiments.Comment: 24 pages, 8 figures, preprint of NIM pape
Carleman estimate and application to an inverse source problem for a viscoelasticity model in anisotropic case
We consider an anisotropic hyperbolic equation with memory term: ∂t2u(x,t)=∑i,j=1n∂i(aij(x)∂ju)+∫0t∑|α|≤2bα(x,t,η)∂xαu(x,η)dη+R(x,t)f(x) for and , which is a simplified model equation for viscoelasticity. The main result is a both-sided Lipschitz stability estimate for an inverse source problem of determining a spatial varying factor of the force term . The proof is based on a Carleman estimate and due to the anisotropy, the existing transformation technique does not work and we introduce a new transformation of u in order to treat the integral terms
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