6,555 research outputs found
Optics measurements for the LHC beam in the TT2-TT10 line and effect of the QKE58 suppression.
Dispersion and optics measurements in TT2-TT10 have been performed for the fast extracted LHC proton beam, to investigate the effect of the QKE58 doublet suppression in the PS (foreseen in 2007) in term of change in the optics parameters at the beginning of the transfer line and of injection mismatch in the SPS. In the note, the results of the November 2006 campaign are discussed and the tools used for the dispersion, Twiss parameters and beam profiles measurements are presented
Dark Universe and distribution of Matter as Quantum Imprinting: the Quantum Origin of Universe
In this paper we analyze the Dark Matter problem and the distribution of
matter through two different approaches, which are linked by the possibility
that the solution of these astronomical puzzles should be sought in the quantum
imprinting of the Universe. The first approach is based on a cosmological model
formulated and developed in the last ten years by the first and third authors
of this paper; the so-called Archaic Universe. The second approach was
formulated by Rosen in 1933 by considering the Friedmann-Einstein equations as
a simple one-dimensional dynamical system reducing the cosmological equations
in terms of a Schroedinger equation. As an example, the quantum memory in
cosmological dynamics could explain the apparently periodic structures of the
Universe while Archaic Universe shows how the quantum phase concernts not only
an ancient era of the Universe, but quantum facets permeating the entire
Universe today.Comment: 18 page
Calibration and correction of the BTVs images
As the screen at the BTV monitor is not orthogonal to the optical axis of the camera, the image acquired by the CCD results distorted. An algorithm to correct for this distortion and other orientation errors is described in this note
Relative entropy via non-sequential recursive pair substitutions
The entropy of an ergodic source is the limit of properly rescaled 1-block
entropies of sources obtained applying successive non-sequential recursive
pairs substitutions (see P. Grassberger 2002 ArXiv:physics/0207023 and D.
Benedetto, E. Caglioti and D. Gabrielli 2006 Jour. Stat. Mech. Theo. Exp. 09
doi:10.1088/1742.-5468/2006/09/P09011). In this paper we prove that the cross
entropy and the Kullback-Leibler divergence can be obtained in a similar way.Comment: 13 pages , 2 figure
LHC LEAD ION BEAM OPTICS WITH LOW-BETA INSERTION FOR THE PS TO SPS TRANSFER LINE
In the context of the LHC operation with lead ions programme, a low beta insertion was implemented in the PS to SPS transfer line TT2, for the stripping foil installation, in order to reduce the beam emittance blow-up at the foil to values consistent with the tight emittance budget of the LHC. Extra quadrupoles and power converters had to be installed in TT2, in order to obtain a satisfactorily low beta at the stripper location and a good quality matching of the line at the SPS injection. The performance of the new optics is discussed and measurements results in TT2 and in the SPS with the "early ion beam" are presented
Proposal for the installation of three additional OTR monitors in the TT2 line
The location of a set of three MTV monitors equipped with OTR (Optical Transition Radiation)screens in the line TT2 is proposed, in order to measure emittance and Twiss parameters of beams ejected from the PS when they are not sent to TT10/SPS and as a complement of downstream measurements. The monitors will be installed during the 2008-2009 machine shutdown
MEAN-FIELD LIMIT FOR PARTICLE SYSTEMS WITH TOPOLOGICAL INTERACTIONS
The mean-field limit for systems of self-propelled agents with “topological interaction” cannot be obtained by means of the usual Dobrushin approach. We get results by adapting to the multidimensional case the techniques developed by Trocheris in 1986 to treat the Vlasov-Poisson equation in one dimension
FIRST EVIDENCE OF OPUNTIA FICUS INDICA LEAVES USED AS SURFACE FINISHING TREATMENTS ON THE PIETRA LECCESE
Lecce stone belongs to the group of Miocene limestone and is distributed in many areas of
the Salento peninsula. The great part of the historical buildings, both religious and civil, in
this area have been constructed with this porous and soft material.
In the past, various methods and recipes have been used to protect the surfaces and ensure
their longevity. However, these ancient "recipes" are unidentified, because these techniques
were known only by the artisans who used them [2].
For this purpose, selected religious and civil buildings in the territory of the province of
Lecce, made of Lecce stone, not yet restored and possibly treated with some of these
unknown recipes because of their good conservation state, were studied and the presence
of surface treatments was investigated.
Samples were analysed by Py/GC-MS with and without thermally assisted hydrolysis and
methylation using tetramethylammonium hydroxide (TMAH). The results of the analyses
showed that these buildings have been protected with different natural products. Moreover,
for the first time, chemical biomarkers demonstrating the use of prickly pear leaves (Opuntia
ficus indica [3]) as protective surface finishes have been identified
Some aspects of the inertial spin model for flocks and related kinetic equations
In this paper, we study the macroscopic behavior of the inertial spin (IS) model. This model has been recently proposed to describe the collective dynamics of flocks of birds, and its main feature is the presence of an auxiliary dynamical variable, a sort of internal spin, which conveys the interaction among the birds with the effect of better describing the turning of flocks. After discussing the geometrical and mechanical properties of the IS model, we show that, in the case of constant interaction among the birds, its mean-field limit is described by a nonlinear Fokker-Planck equation, whose equilibria are fully characterized. Finally, in the case of non-constant interactions, we derive the kinetic equation for the mean-field limit of the model in the absence of thermal noise, and explore its macroscopic behavior by analyzing the mono-kinetic solutions
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