7,824 research outputs found
Open Questions in the Understanding of Strangeness Production in HIC -- Experiment Perspective
Open questions concerning strangeness production in heavy-ion collisions are
discussed with a focus on the experimental aspects. The open points are
presented in the context of recent measurements.Comment: Proceedings for the Strange Quark Matter 2017 conference in Utrecht,
Netherland
Strangeness Production at the SPS
Systematic studies on the production of strange hyperons and the phi meson as
a function of beam energy and system size performed by the NA49 collaboration
are discussed. Hadronic transport models fail to describe the production of
multi strange particles (Xi, Omega), while statistical models are generally in
good agreement to the measured particle yields at all energies. The system size
dependence is well reproduced by the core-corona approach. New data on K*(892)
production are presented. The yields of these short-lived resonances are
significantly below the statistical model expectation. This is in line with the
interpretation that the measurable yields are reduced due to rescattering of
their decay products inside the fireball.Comment: Proceedings to the ISMD09 Conference. 5 pages, 6 figure
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
Application of pressurized liquid nitrogen inside parametric-amplifier structures for input-noise-temperature improvement
Pressurized liquid nitrogen inside parametric amplifier structures for input, noise, and temperature improvement
Unification and limitations of error suppression techniques for adiabatic quantum computing
While adiabatic quantum computation (AQC) possesses some intrinsic robustness
to noise, it is expected that a form of error control will be necessary for
large scale computations. Error control ideas developed for circuit-model
quantum computation do not transfer easily to the AQC model and to date there
have been two main proposals to suppress errors during an AQC implementation:
energy gap protection and dynamical decoupling. Here we show that these two
methods are fundamentally related and may be analyzed within the same
formalism. We analyze the effectiveness of such error suppression techniques
and identify critical constraints on the performance of error suppression in
AQC, suggesting that error suppression by itself is insufficient for
fault-tolerant, large-scale AQC and that a form of error correction is needed.
This manuscript has been superseded by the articles, "Error suppression and
error correction in adiabatic quantum computation I: techniques and
challenges," arXiv:1307.5893, and "Error suppression and error correction in
adiabatic quantum computation II: non-equilibrium dynamics," arXiv:1307.5892.Comment: 9 pages. Update replaces "Equivalence" with "Unification." This
manuscript has been superseded by the two-article series: arXiv:1307.5892 and
arXiv:1307.589
System Size Dependence of Particle Production at the SPS
Recent results on the system size dependence of net-baryon and hyperon
production as measured at the CERN SPS are discussed. The observed Npart
dependences of yields, but also of dynamical properties, such as average
transverse momenta, can be described in the context of the core corona
approach. Other observables, such as antiproton yields and net-protons at
forward rapidities, do not follow the predictions of this model. Possible
implications for a search for a critical point in the QCD phase diagram are
discussed. Event-by-event fluctuations of the relative core to corona source
contributions might influence fluctuation observables (e.g. multiplicity
fluctuations). The magnitude of this effect is investigated.Comment: 10 pages, 4 figurs. Proceedings of the 6th International Workshop on
Critical Point and Onset of Deconfinement in Dubna, Aug. 201
The Trapped Polarized Fermi Gas at Unitarity
We consider population-imbalanced two-component Fermi gases under external
harmonic confinement interacting through short-range two-body potentials with
diverging s-wave scattering length. Using the fixed-node diffusion Monte Carlo
method, the energies of the "normal state" are determined as functions of the
population-imbalance and the number of particles. The energies of the trapped
system follow, to a good approximation, a universal curve even for fairly small
systems. A simple parameterization of the universal curve is presented and
related to the equation of state of the bulk system.Comment: 4 pages, 2 tables, 2 figure
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