1,949 research outputs found
A New Approach for Reconstructing SUSY Particle Masses with a few fb^(-1) at the LHC
We describe a new cascade mass reconstruction approach to allow
reconstruction of SUSY particle masses in long cascades (five or more
particles) at the LHC with integrated luminosity as low as a few fb^(-1). This
approach is based on a consecutive use of the endpoint method, an event filter
and a combinatorial mass reconstruction method. The endpoint method gives a
preliminary estimate of light sparticle masses. An event filter combining the
maximum likelihood distributions for all events in the data sample allows
suppression of backgrounds and gives a preliminary estimate of heavy sparticle
masses. Finally, SUSY particle masses are reconstructed by a search for a
maximum of a combined likelihood function constructed for each possible
combination of five events in the data sample.
SUSY data sample sets for the SU3 model point containing 80k events each were
generated, corresponding to an integrated luminosity of 4.2 fb^(-1). These
events were passed through the AcerDET detector simulator, which parametrized
the response of a detector. To demonstrate the stability and precision of the
approach five different 80k event data sets were considered. Masses were
reconstructed with a precision of about 10% for heavy sparticles and 10-20% for
light sparticles.Comment: 23 pages, 9 figures, added 1 referenc
Angular asymmetries as a probe for anomalous contributions to HZZ vertex at the LHC
In this article, the prospects for studying the tensor structure of the HZZ
vertex with the LHC experiments are presented. The structure of tensor
couplings in Higgs di-boson decays is investigated by measuring the asymmetries
and by studing the shapes of the final state angular distributions. The
expected background contributions, detector resolution, and trigger and
selection efficiencies are taken into account. The potential of the LHC
experiments to discover sizeable non-Standard Model contributions to the HZZ
vertex with and is demonstrated.Comment: 9 pages, 8 figures; added 3 references for section 1; added 3
references, added missing unit GeV in Table III and 4 clarifying sentences to
the tex
Reconstruction of the bubble nucleating potential
We calculate analytically the bubble nucleation rate in a model of first
order inflation which is able to produce large scale structure. The computation
includes the first-order departure from the thin-wall limit, the explicit
derivation of the pre-exponential factor, and the gravitational correction. The
resulting bubble spectrum is then compared with constraints from the large
scale structure and the microwave background. We show that there are models
which pass all the constraints and produce bubble-like perturbations of
interesting size. Furthermore, we show that it is in principle possible to
reconstruct completely the inflationary two-field potential from observations.Comment: Accepted for publication in Phys. Rev. D, 19 pages, 2 ps figs
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