15,121 research outputs found
Dedicated front-end electronics for the next generation of linear collider electromagnetic calorimeter
This paper describes an R&D electronic program for the next generation of
linear collider electromagnetic calorimeter. After a brief presentation of the
requirements, a global scheme of the electronics is given. Then, we describe
the three different building blocks developed in 0.35\mum CMOS technology: an
amplifier, a comparator and finally the pipelined AD
Equilibrium and off-equilibrium simulations of the 4d Gaussian spin glass
In this paper we study the on and off-equilibrium properties of the four
dimensional Gaussian spin glass. In the static case we determine with more
precision that in previous simulations both the critical temperature as well as
the critical exponents. In the off-equilibrium case we settle the general form
of the autocorrelation function, and show that is possible to obtain
dynamically, for the first time, a value for the order parameter.Comment: 16 pages and 13 figures, uses epsfig.sty and rotate.sty. Some minor
grammatical changes. Also available at
http://chimera.roma1.infn.it/index_papers_complex.htm
The proton structure function F2 in the resonance region
Unique measurement of the proton structure function F2 in a wide
two-dimensional region of x and Q**2 has been reported. The accessible
kinematics covers entire resonance region up to W=2.5 GeV in the Q**2 interval
from 0.1 to 4.5 GeV**2. Obtained data allowed for the first time an evaluation
of moments of the structure function F2 directly from experimental data as well
as an intensive study of the Bloom-Gilman duality phenomenon.Comment: 6 pages, 4 figures, Proceedings of GDH2002 Conference, 3-6 July 2002,
Genova, Italy, to be published in World Scientifi
The SKA view of the Neutral Interstellar Medium in Galaxies
Two major questions in galaxy evolution are how star-formation on small
scales leads to global scaling laws and how galaxies acquire sufficient gas to
sustain their star formation rates. HI observations with high angular
resolution and with sensitivity to very low column densities are some of the
important observational ingredients that are currently still missing. Answers
to these questions are necessary for a correct interpretation of observations
of galaxy evolution in the high-redshift universe and will provide crucial
input for the sub-grid physics in hydrodynamical simulations of galaxy
evolutions. In this chapter we discuss the progress that will be made with the
SKA using targeted observations of nearby individual disk and dwarf galaxies.Comment: 22 pages, 4 figures, to appear as part of 'Neutral Hydrogen' in
Proceedings 'Advancing Astrophysics with the SKA (AASKA14)', PoS(AASKA14)12
First astrophysical results from AMBER/VLTI
The AMBER instrument installed at the Very Large Telescope (VLT) combines
three beams from as many telescopes to produce spectrally dispersed fringes
from milli-arcsecond angular scale in the near infrared. Two years after
installation, first scientific observations have been carried out during the
Science Demonstration Time and the Guaranteed Time mostly on bright sources due
to some VLTI limitations. In this paper, we review these first astrophysical
results and we show which types of completely new information is brought by
AMBER. The first astrophysical results have been mainly focusing on stellar
wind structure, kinematics, and its interaction with dust usually concentrated
in a disk. Because AMBER has dramatically increased the number of measures per
baseline, this instrument brings strong constraints on morphology and models
despite a relatively poor (u, v) coverage for each object.Comment: SPIE 6268 proceeding
Quarkonia production with the Hera-B experiment
Measurements of the dependence of the J/Psi production cross section on its
kinematic variables as well as on the target atomic numbers for 920 GeV/c
protons incident on different targets have been made with the Hera-B detector.
The large collected di-lepton sample allows to study the production ratio of
Psi(2S) to J/Psi and of Chic to J/Psi . We also report on measurements of the
b-bbar and Upsilon production cross section.Comment: 9 pages, 11 figure
Grid services for the MAGIC experiment
Exploring signals from the outer space has become an observational science
under fast expansion. On the basis of its advanced technology the MAGIC
telescope is the natural building block for the first large scale ground based
high energy gamma-ray observatory. The low energy threshold for gamma-rays
together with different background sources leads to a considerable amount of
data. The analysis will be done in different institutes spread over Europe.
Therefore MAGIC offers the opportunity to use the Grid technology to setup a
distributed computational and data intensive analysis system with the nowadays
available technology. Benefits of Grid computing for the MAGIC telescope are
presented.Comment: 5 pages, 1 figures, to be published in the Proceedings of the 6th
International Symposium ''Frontiers of Fundamental and Computational
Physics'' (FFP6), Udine (Italy), Sep. 26-29, 200
The VIMOS-VLT Deep Survey: Dependence of galaxy clustering on stellar mass
We have investigated the dependence of galaxy clustering on their stellar
mass at z~1, using the data from the VIMOS-VLT Deep Survey (VVDS). We have
measured the projected two-point correlation function of galaxies, wp(rp) for a
set of stellar mass selected samples at an effective redshift =0.85. We have
control and quantify all effects on galaxy clustering due to the incompleteness
of our low mass samples. We find that more massive galaxies are more clustered.
When compared to similar results at z~0.1 in the SDSS, we observed no evolution
of the projected correlation function for massive galaxies. These objects
present a stronger linear bias at z~1 with respect to low mass galaxies. As
expected, massive objects at high redshift are found in the highest pics of the
dark matter density field.Comment: 4 pages, 2 figures, 43rd Rencontres de Moriond - March 15-22, 2008 -
La Thuile (Val d'Aosta, Italy
The Finite Size SU(3) Perk-Schultz Model with Deformation Parameter q=exp(i 2 pi/3)
From extensive numeric diagonalizations of the SU(3) Perk-Schultz Hamiltonian
with a special value of the anisotropy and different boundary conditions, we
have observed simple regularities for a significant part of its eigenspectrum.
In particular the ground state energy and nearby excitations belong to this
part of the spectrum.
Our simple formulae describing these regularities remind, apart from some
selection rules, the eigenspectrum of the free fermion model. Based on the
numerical observations we formulate several conjectures. Using explicit
solutions of the associated nested Bethe-ansatz equations, guessed from an
analysis of the functional equations of the model, we provide evidence for a
part of them.Comment: 19 pages, no figure
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