5,442 research outputs found
Initial Conditions for Large Cosmological Simulations
This technical paper describes a software package that was designed to
produce initial conditions for large cosmological simulations in the context of
the Horizon collaboration. These tools generalize E. Bertschinger's Grafic1
software to distributed parallel architectures and offer a flexible alternative
to the Grafic2 software for ``zoom'' initial conditions, at the price of large
cumulated cpu and memory usage. The codes have been validated up to resolutions
of 4096^3 and were used to generate the initial conditions of large
hydrodynamical and dark matter simulations. They also provide means to generate
constrained realisations for the purpose of generating initial conditions
compatible with, e.g. the local group, or the SDSS catalog.Comment: 12 pages, 11 figures, submitted to ApJ
Search for oscillations using inclusive lepton events
A new search for Bs oscillations is performed in a sample of semileptonic b-hadron decays collected by the ALEPH experiment during 1991-1995. Compared to previous inclusive lepton analyses, the proper time resolution and mistag are significantly improved. In addition sub-samples of the data are assigned an enriched or depleted Bs fraction. Maximum likelihood fits are performed to derive a preliminary lower limit of Dms > 10.2 ps-1 at 95L. Combining with the ALEPH Ds based analyses yields Dms>10.4 ps-1 at 95L
WIRELESS AND BATTERYLESS SURFACE ACOUSTIC WAVE SENSORS FOR HIGH TEMPERATURE ENVIRONMENTS
International audienceSurface acoustic wave (SAW) devices are widely used as filter, resonator or delay line in electronic systems in a wide range of applications: mobile communication, TVs, radar, stable resonator for clock generation, etc. The resonance frequency and the delay line of SAW devices are depending on the properties of materials forming the device and could be very sensitive to the physical parameters of the environment. Since SAW devices are more and more used as sensor for a large variety of area: gas, pressure, force, temperature, strain, radiation, etc. The sensors based SAW present the advantage to be passive (batteryless) and/or wireless. These interesting properties combined with a small size, a low cost radio request system and a small antennas when operating at high frequency, offer new and exiting perspectives for wireless measurement processes and IDTAG applications. When the materials constituting the devices are properly selected, it becomes possible to use those sensors without embedded electronic in hostile environments (as high temperature, nuclear site, …) where no solutions are currently used. General principle of the SAW sensor in wired and wireless configurations will be developed and a review of recent works concerning the field of high temperature applications will be presented with specific attention given to the choice of materials constituting the SAW device
Massive Stars in the Range : Evolution and Nucleosynthesis. II. the Solar Metallicity Models
We present the evolutionary properties of a set of massive stellar models
(namely 13, 15, 20 and 25 ) from the main sequence phase up to the
onset of the iron core collapse. All these models have initial solar chemical
composition, i.e. Y=0.285 and Z=0.02. A 179 isotope network, extending from
neutron up to and fully coupled to the evolutionary code has been
adopted from the Carbon burning onward. Our results are compared, whenever
possible, to similar computations available in literature.Comment: 42 pages, 18 figures, 26 tables, accepted for publicatin in ApJ
Many-body theory interpretation of deep inelastic scattering
We analyze data on deep inelastic scattering of electrons from the proton
using ideas from standard many-body theory involving {\em bound} constituents
subject to {\em interactions}. This leads us to expect, at large three-momentum
transfer , scaling in terms of the variable . The response at constant scales well in this variable.
Interaction effects are manifestly displayed in this approach. They are
illustrated in two examples.Comment: 10 pages, 4 figure
Suppressed decay into open charm for the Y(4260) being an hybrid
We investigate the Y(4260) resonance recently discovered by the Babar
collaboration. We propose the observation of its decay into J/psi pi pi and its
non observation into open charm as a consequence of it being a charmonium
hybrid state with a magnetic constituent gluon. We prove a selection rule
forbidding its decay into two S-wave charmed mesons in any potential model. We
suggest a generalisation of the selection rule based only on the heavy quark
nature of the charm.Comment: 5 page
Q**2-dependence of deep inelastic lepton scattering off nuclear targets
Deep inelastic scattering of leptons off nuclear targets is analized within
the convolution model taking into account nucleon-nucleon correlations. We show
that in the nuclear medium nucleons are distributed according to a function
that exhibits a sizeable Q**2-dependence and reduces to the ordinary light-cone
distribution in the Bjorken limit. At Q**2 1 this
Q**2-dependence turns out to be stronger than the one associated with the
nucleon structure function, predicted by pertubative quantum chromodynamics.Comment: 11 pages including figs. Figs. can be sent by PS-fil
Two charged strangeonium-like structures observable in the process
Via the Initial Single Pion Emission (ISPE) mechanism, we study the
invariant mass spectrum distribution of . Our calculation indicates there exist a sharp peak
structure () close to the threshold and a broad
structure () near the threshold. In addition, we
also investigate the process due to
the ISPE mechanism, where a sharp peak around the threshold
appears in the invariant mass spectrum distribution. We
suggest to carry out the search for these charged strangeonium-like structures
in future experiment, especially Belle II, Super-B and BESIII.Comment: 7 pages, 5 figures. Accepted by Eur. Phys. J.
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