7,295 research outputs found
Stopping in central Pb + Pb collisions at SPS energies and beyond
We investigate stopping and baryon transport in central relativistic Pb + Pb
and Au + Au collisions. At energies reached at the CERN Super Proton
Synchrotron [sqrt(s_NN) = 6.3-17.3 GeV] and at RHIC (62.4 GeV), we determine
the fragmentation-peak positions from the data. The resulting linear growth of
the peak positions with beam rapidity is in agreement with our results from a
QCD-based approach that accounts for gluon saturation. No discontinuities in
the net-proton fragmentation peak positions occur in the expected transition
region from partons to hadrons at 6-10 GeV.Comment: 5 pages, 3 figures, 1 table. Figures updated, table shortened, 1
reference adde
Learning and Communication in Sender-Reciever Games: An Economic Investigation
This paper compares the performance of stimulus response (SR) and belief-based learning (BBL) using data from game theory experiments. The environment, extensive form games played in a population setting, is novel in the empirical literature on learning in games. Both the SR and BBL models fit the data reasonably well in common interest games with history while the test results accept SR and reject BBL in games with no history and in all but one of the divergent interest games. Estimation is challenging since the likelihood function is not globally concave and the results may be subject to convergence bias.econometrics;game theory and experiments
Pseudo-potential treatment of two aligned dipoles under external harmonic confinement
Dipolar Bose and Fermi gases, which are currently being studied extensively
experimentally and theoretically, interact through anisotropic, long-range
potentials. Here, we replace the long-range potential by a zero-range
pseudo-potential that simplifies the theoretical treatment of two dipolar
particles in a harmonic trap. Our zero-range pseudo-potential description
reproduces the energy spectrum of two dipoles interacting through a
shape-dependent potential under external confinement very well, provided that
sufficiently many partial waves are included, and readily leads to a
classification scheme of the energy spectrum in terms of approximate angular
momentum quantum numbers. The results may be directly relevant to the physics
of dipolar gases loaded into optical lattices.Comment: 9 pages, 4 figure
PHENIX and the Reaction Plane: Recent Results
During the past several years, experiments at RHIC have established that a
dense partonic medium is produced in Au+Au collisions at sqrt(s)=200 GeV.
Subsequently, a primary goal of analysis has been to understand and
characterize the dynamics underlying this new form of matter. Among the many
probes available, the measurements with respect to the reaction plane has
proven to be crucial to our understanding of a wide range of topics, from the
hydrodynamics of the initial expansion of the collision region to high-pt jet
quenching phenomena. Few tools have the ability to shed light on such a wide
variety of observables as the reacion plane. In this article, we discuss recent
PHENIX measurements with respect to the reaction plane, and the implications
for understanding the underlying physics of RHIC collisions.Comment: 9 pages, 13 figures, Submitted for proceedings to the Winter Workshop
on Nuclear Dynamics 2010, Ocho Rios, Jamaic
Practical learning method for multi-scale entangled states
We describe a method for reconstructing multi-scale entangled states from a
small number of efficiently-implementable measurements and fast
post-processing. The method only requires single particle measurements and the
total number of measurements is polynomial in the number of particles. Data
post-processing for state reconstruction uses standard tools, namely matrix
diagonalisation and conjugate gradient method, and scales polynomially with the
number of particles. Our method prevents the build-up of errors from both
numerical and experimental imperfections
Efeito de agentes de controle biológico na indução de resistência em videira.
O objetivo deste trabalho foi avaliar o efeito de agentes comerciais de controle biolĂłgico como indutores de resistĂŞncia em videira para o controle do mĂldio
Dilute Bose gases interacting via power-law potentials
Neutral atoms interact through a van der Waals potential which asymptotically
falls off as r^{-6}. In ultracold gases, this interaction can be described to a
good approximation by the atom-atom scattering length. However, corrections
arise that depend on the characteristic length of the van der Waals potential.
We parameterize these corrections by analyzing the energies of two- and
few-atom systems under external harmonic confinement, obtained by numerically
and analytically solving the Schrodinger equation. We generalize our results to
particles interacting through a longer-ranged potential which asymptotically
falls off as r^{-4}.Comment: 7 pages, 4 figure
Power estimation on functional level for programmable processors
In diesem Beitrag werden verschiedene Ansätze zur Verlustleistungsschätzung von programmierbaren Prozessoren vorgestellt und bezüglich ihrer Übertragbarkeit auf moderne Prozessor-Architekturen wie beispielsweise Very Long Instruction Word (VLIW)-Architekturen bewertet. Besonderes Augenmerk liegt hierbei auf dem Konzept der sogenannten Functional-Level Power Analysis (FLPA). Dieser Ansatz basiert auf der Einteilung der Prozessor-Architektur in funktionale Blöcke wie beispielsweise Processing-Unit, Clock-Netzwerk, interner Speicher und andere. Die Verlustleistungsaufnahme dieser Bl¨ocke wird parameterabhängig durch arithmetische Modellfunktionen beschrieben. Durch automatisierte Analyse von Assemblercodes des zu schätzenden Systems mittels eines Parsers können die Eingangsparameter wie beispielsweise der erzielte Parallelitätsgrad oder die Art des Speicherzugriffs gewonnen werden. Dieser Ansatz wird am Beispiel zweier moderner digitaler Signalprozessoren durch eine Vielzahl von Basis-Algorithmen der digitalen Signalverarbeitung evaluiert. Die ermittelten Schätzwerte für die einzelnen Algorithmen werden dabei mit physikalisch gemessenen Werten verglichen. Es ergibt sich ein sehr kleiner maximaler Schätzfehler von 3%.</p><p style="line-height: 20px;"> In this contribution different approaches for power estimation for programmable processors are presented and evaluated concerning their capability to be applied to modern digital signal processor architectures like e.g. Very Long InstructionWord (VLIW) -architectures. Special emphasis will be laid on the concept of so-called Functional-Level Power Analysis (FLPA). This approach is based on the separation of the processor architecture into functional blocks like e.g. processing unit, clock network, internal memory and others. The power consumption of these blocks is described by parameter dependent arithmetic model functions. By application of a parser based automized analysis of assembler codes of the systems to be estimated the input parameters of the Correspondence to: H. Blume ([email protected]) arithmetic functions like e.g. the achieved degree of parallelism or the kind and number of memory accesses can be computed. This approach is exemplarily demonstrated and evaluated applying two modern digital signal processors and a variety of basic algorithms of digital signal processing. The resulting estimation values for the inspected algorithms are compared to physically measured values. A resulting maximum estimation error of 3% is achieved
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