8,102 research outputs found
Model-independent constraints on contact interactions from LEP2 data analysis
We derive model-independent constraints on four-fermion contact
interaction-type dynamics from the published preliminary LEP2 experimental data
on e^+e^- annihilation into \mu^+\mu^- and \tau^+\tau^- pairs, measured at
different energies between 130 and 207 GeV. The basic observables are chosen to
be the total cross section and the forward-backward asymmetry, and the analysis
realistically takes into account data uncertainties and correlations among
measurements at the various energies. The combination of data from different
energy points plays an important role in the determination of regions allowed
for the contact interaction coupling constants. In contrast to the more common
one-parameter analyses, we only obtain constraints on pairs of parameters
rather than limits on individual ones.Comment: 13 pages, LaTeX, including figures. v2: Included discussion of tau
data, version to appear in EPJ
SUSTAINABLE CONCEPT FOR BORDER SETTLEMENT AT KAMPUNG ROMO KALISARI SURABAYA
The development of a city tend only to pay attention to the downtown area than in the border area. It can also be seen in the city of Surabaya, particularly in Sub-district Romo Kalisari which is a border kampung between Surabaya and Gresik. Border area is the main access from out of Surabaya to go to other cities and shows the identity of towns, especially to give a first impression on the city. But in Kampung Romo Kalisari, it has not been seen any effort to improve the quality of people.According to the theory used in this study, one of the things that are important in the development of the sustainable city is the economic improvement, particularly on the city's infrastructure. Border area also needs a management that supports the development of sustainable cities. Therefore, this study will provide concrete solutions on improving the city's infrastructure, such as transport and education facilities as well as the trade, which can be applied in the development of border kampungs in the Kampung Romo Kalisari, Surabaya
The Estimation of the Effective Centre of Mass Energy in q-qbar-gamma Events from DELPHI
The photon radiation in the initial state lowers the energy available for the
ee collisions; this effect is particularly important at LEP2 energies
(above the mass of the Z boson). Being aligned to the beam direction, such
initial state radiation is mostly undetected. This article describes the
procedure used by the DELPHI experiment at LEP to estimate the effective
centre-of-mass energy in hadronic events collected at energies above the Z
peak. Typical resolutions ranging from 2 to 3 GeV on the effective
center-of-mass energy are achieved, depending on the event topology.Comment: 12 pages, 6 figure
A selected ion flow tube study of the reactions of gas-phase cations with PSCl3
A selected ion flow tube was used to investigate the positive ion chemistry of thiophosphoryl chloride, PSCl. Rate coefficients and ion product branching ratios have been determined at room temperature for reactions with nineteen cations ; HO, CF, CF, NO, NO, SF, SF, CF, O, HO, NO, O, CO, CO, N, N, Ar, F and Ne (in order of increasing recombination energy). Complementary data described in the previous paper have been obtained for this molecule via the observation of threshold photoelectron photoion coincidences. For ions whose recombination energies are in the range 10-22 eV, comparisons are made between the product ion branching rations of PSCl from photoionisation and from ion-molecule reactions. In most instances, the data from the two experiments are well correlated, suggesting that long-range charge transfer is the dominant mechanism for these ion-molecule reactions ; the agreement is particularly good for the atomic ions Ar, F and Ne. Some reactions (e.g. O + PSCl), however, exhibit significant differences; short-range charge transfer must then be occurring following the formation of an ion-molecule complex. For ions whose recombination energies are less than 10 eV (i.e. HO, CF, CF and NO), reactions can only occur via a chemical process in which bonds are broken and formed, because the recombination energy of the cation is less than the ionisation energy of PSCl
Finite-gap Solutions of the Vortex Filament Equation: Isoperiodic Deformations
We study the topology of quasiperiodic solutions of the vortex filament
equation in a neighborhood of multiply covered circles. We construct these
solutions by means of a sequence of isoperiodic deformations, at each step of
which a real double point is "unpinched" to produce a new pair of branch points
and therefore a solution of higher genus. We prove that every step in this
process corresponds to a cabling operation on the previous curve, and we
provide a labelling scheme that matches the deformation data with the knot type
of the resulting filament.Comment: 33 pages, 5 figures; submitted to Journal of Nonlinear Scienc
Preliminary archaeometric analysis on a marble bas-relief of unknown origin
This paper addresses an archaeometric study of a marble bas-relief seized by the Cosenza Carabinieri Unit for the Protection of Cultural Heritage and Anti-Counterfeiting (Calabria, Italy). The research aimed to collect data on the authenticity of the artwork, providing indications about the compositional features of the sampled materials. An analytical approach based on the use of SEM-EDX and FT-IR techniques along with a stylistic evaluation of the artwork, allowed us to answer the requests posed by the institutions and to set the work in a different historical context from the Roman production
The on-ground calibration of the flight model of the HPGSPC onboard the SAX satellite: Calibration set-up and preliminary results
The High Pressure Gas Scintillation Proportional Counter (HPGSPC) is one of the Narrow Field Instruments of the Italian-Dutch X-ray astronomy satellite SAX. Sensitive in the hard X-ray band (4–120 keV), with a very good energy
resolution, the HPGSPC is well suited for studying in detail the cyclotron features present in the hard X-ray spectrum of some celestial sources. The scientific
calibration of the flight model of the HPGSPC took place at the LABEN premises(Vimodrone-Milano) during October and November 1994. In this paper we briefly describe the
on-ground instrument calibration system and we report some
preliminary results that show the performances of both single/double event and position reconstruction/energy correction onboard processing. Preliminary results
concerning the energy resolution and energy linearity are reported too
A Multi-Analytical Diagnostic on an Outdoor Wall Painting: The Study on the Déesis of St. Maria Annunziata’s Church, Motta San Giovanni (Reggio Calabria, Italy)
This article concerns the diagnostic campaign aimed at analyzing the mural painting representing the iconographic theme of the Deesis of the Church of St. Maria Annunziata, Motta San Giovanni, in the province of Reggio Calabria. In 1951, a flood caused the collapse of the building and the consequent breaking of the apse into two parts. The present study focused on the left side of the apse, hosting the figures of Christ and Mary, in order to plan the best conservation intervention strategy. For this purpose, non-invasive investigations and laboratory analytical methods were conducted in order to characterize the constituent materials and to identify the forms of alteration and degradation present on the surface of the painting. In particular, Raman spectroscopy, optical microscopy, scanning electron microscopy coupled to the chemical analysis by an EDS probe, Fourier-transform infrared spectroscopy and ion chromatography were employed. The results highlighted the presence of a single layer of plaster made with a lime-based binder. The chromatic palette of the painting is characterized by ochres and carbon black mixed with lime to obtain the different shades. Finally, the definition of the nature of the deposits and of the overlaid materials was fundamental in order to identify the best products and methods to restore the readability of the work
A mixed integer linear program to compress transition probability matrices in Markov chain bootstrapping
Bootstrapping time series is one of the most acknowledged tools to study the statistical properties of an evolutive phenomenon. An important class of bootstrapping methods is based on the assumption that the sampled phenomenon evolves according to a Markov chain. This assumption does not apply when the process takes values in a continuous set, as it frequently happens with time series related to economic and financial phenomena. In this paper we apply the Markov chain theory for bootstrapping continuous-valued processes, starting from a suitable discretization of the support that provides the state space of a Markov chain of order k≥1. Even for small k, the number of rows of the transition probability matrix is generally too large and, in many practical cases, it may incorporate much more information than it is really required to replicate the phenomenon satisfactorily. The paper aims to study the problem of compressing the transition probability matrix while preserving the “law” characterising the process that generates the observed time series, in order to obtain bootstrapped series that maintain the typical features of the observed time series. For this purpose, we formulate a partitioning problem of the set of rows of such a matrix and propose a mixed integer linear program specifically tailored for this particular problem. We also provide an empirical analysis by applying our model to the time series of Spanish and German electricity prices, and we show that, in these medium size real-life instances, bootstrapped time series reproduce the typical features of the ones under observation.
This is a post-peer-review, pre-copyedit version of an article published in Annals of Operations Research volume. The final authenticated version is available online at: http://dx.doi.org/10.1007/s10479-016-2181-
Performance of a Tungsten-Cerium Fluoride Sampling Calorimeter in High-Energy Electron Beam Tests
A prototype for a sampling calorimeter made out of cerium fluoride crystals
interleaved with tungsten plates, and read out by wavelength-shifting fibres,
has been exposed to beams of electrons with energies between 20 and 150 GeV,
produced by the CERN Super Proton Synchrotron accelerator complex. The
performance of the prototype is presented and compared to that of a Geant4
simulation of the apparatus. Particular emphasis is given to the response
uniformity across the channel front face, and to the prototype's energy
resolution.Comment: 6 pages, 6 figures, Submitted to NIM
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