8,001 research outputs found
Recent Results on Strangeness Production from CERN Experiment NA49
New results from NA49 on the production of strangeness in elementary and
nuclear reactions are presented. New measurements of charged kaon and pion
production have been obtained from 40 AGeV Pb+Pb collisions. The evolution of
strange meson yields in nucleus-nucleus interactions is studied as a function
of collision energy and system size. Cascade baryon yields are presented for a
wide range of hadronic interactions including first measurements in p+p and
centrality controlled p+Pb collisions.Comment: 4 pages, 4 figures, to be published in the Proceedings of XXXVIth
Rencontre de Moriond, QCD and High Energy Hadronic Interactions, March 200
Baryon Number Transfer in Hadron+Nucleus and Nucleus+Nucleus Collisions: A Link between Elementary and Complex Interactions
The baryon number transfer is studied in elementary and complex hadronic
interactions at the CERN experiment NA49 at the SPS, at 158 AGeV beam energy
(\sqrt{s}=17.2 GeV). A two component picture is proposed, which builds up the
net proton distribution from a target and a projectile component. Using pion
beam, the projectile component is experimentally determined for p+p and p+A
interactions. A similar stopping behaviour of the projectile component is found
for p+A and A+A interactions. Based on these observations, the baryon transfer
is assumed to provide a common scale of inelasticity in p+p, p+A and A+A
interactions. A model-independent way is proposed to predict the pion
multiplicity in A+A.Comment: 10 pages, 12 figures. To appear in the proceedings of International
Workshop on Quark and Hadron Dynamics in Relativistic Heavy Ion Collisions
(BP 2002), Budapest, Hungary, 3-7 Mar 200
Creating temperature dependent Ni-MH battery models for low power mobile devices
In this paper the methodology and the results of creating temperature
dependent battery models for ambient intelligence applications is presented.
First the measurement technology and the model generation process is presented
in details, and then the characteristic features of the models are discussed.Comment: Submitted on behalf of TIMA Editions
(http://irevues.inist.fr/tima-editions
On Renyi entropies characterizing the shape and the extension of the phase space representation of quantum wave functions in disordered systems
We discuss some properties of the generalized entropies, called Renyi
entropies and their application to the case of continuous distributions. In
particular it is shown that these measures of complexity can be divergent,
however, their differences are free from these divergences thus enabling them
to be good candidates for the description of the extension and the shape of
continuous distributions. We apply this formalism to the projection of wave
functions onto the coherent state basis, i.e. to the Husimi representation. We
also show how the localization properties of the Husimi distribution on average
can be reconstructed from its marginal distributions that are calculated in
position and momentum space in the case when the phase space has no structure,
i.e. no classical limit can be defined. Numerical simulations on a one
dimensional disordered system corroborate our expectations.Comment: 8 pages with 2 embedded eps figures, RevTex4, AmsMath included,
submitted to PR
Comments concerning the paper "Measurement of negatively charged pion spectra in inelastic p+p interactions at 20, 31, 40, 80 and 158 GeV/c" by the NA61 collaboration
New data from the NA61 collaboration on the production of negative pions in
p+p interactions at beam momenta between 20 and 158 GeV/c are critically
compared to available results in the same energy range. It is concluded that
the NA61 data show some discrepancies with the previous results. This concerns
in particular the total yields, the integrated rapidity distributions and
the double differential cross sections.Comment: 16 pages, 13 figure
Information Length and Localization in One Dimension
The scaling properties of the wave functions in finite samples of the one
dimensional Anderson model are analyzed. The states have been characterized
using a new form of the information or entropic length, and compared with
analytical results obtained by assuming an exponential envelope function. A
perfect agreement is obtained already for systems of -- sites over
a very wide range of disorder parameter . Implications for
higher dimensions are also presented.Comment: 11 pages (+3 Figures upon request), Plain TE
Occupation probability of harmonic-oscillator quanta for microscopic cluster-model wave functions
We present a new and simple method of calculating the occupation probability
of the number of total harmonic-oscillator quanta for a microscopic
cluster-model wave function. Examples of applications are given to the recent
calculations including -model for He, -model for
Li, and -model for Be as well as the classical
calculations of -model for Li and -model
for C. The analysis is found to be useful for quantifying the amount of
excitations across the major shell as well as the degree of clustering. The
origin of the antistretching effect is discussed.Comment: 9 page
Positron scattering and annihilation from the hydrogen molecule at zero energy
The confined variational method is used to generate a basis of correlated
gaussians to describe the interaction region wave function for positron
scattering from the H molecule. The scattering length was
while the zero energy of 15.7 is compatible with
experimental values. The variation of the scattering length and
with inter-nuclear distance was surprisingly rapid due to virtual state
formation at
Nematic order of model goethite nanorods in a magnetic field
We explore the nematic order of model goethite nanorods in an external
magnetic field within Onsager-Parsons density functional theory. The goethite
rods are represented by monodisperse, charged spherocylinders with a permanent
magnetic moment along the rod main axis, forcing the particles to align
parallel to the magnetic field at low field strength. The intrinsic diamagnetic
susceptibility anisometry of the rods is negative which leads to a preferred
perpendicular orientation at higher field strength. It is shown that these
counteracting effects may give rise to intricate phase behavior, including a
pronounced stability of biaxial nematic order and the presence of reentrant
phase transitions and demixing phenomena. The effect of the applied field on
the nematic-to-smectic transition will also be addressed.Comment: 12 pages, 5 figures, submitted to Phys. Rev.
Shell model on a random gaussian basis
Pauli-projected random gaussians are used as a representation to solve the
shell model equations. The elements of the representation are chosen by a
variational procedure. This scheme is particularly suited to describe cluster
formation and cluster decay in nuclei. It overcomes the basis-size problem of
the ordinary shell model and the technical difficulties of the
cluster-configuration shell model. The model reproduces the -decay
width of Po satisfactorily.Comment: Latex, Submitted to Phys. Lett. B, 7 pages, 2 figures available upon
request, ATOMKI-1994-
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