8,709 research outputs found
Asymmetry studies in Lambda 0/Lambda 0-bar, Xi-/Xi+ and Omega-/Omega+ production
We present a study on hyperon/anti-hyperon production asymmetries in the
framework of the recombination model. The production asymmetries for Lambda
0/Lambda 0-bar, Xi-/Xi+ and Omega-/Omega+ are studied as a function of x_F.
Predictions of the model are compared to preliminary data on
hyperon/anti-hyperon production asymmetries in 500 GeV/c pi- p interactions
from the Fermilab E791 experiment. The model predicts a growing asymmetry with
the number of valence quarks shared by the target and the produced hyperons in
the x_F < 0 region. In the positive x_F region, the model predicts constant
asymmetries for Lambda 0/Lambda 0-bar and Omega-/Omega+ production and a
growing asymmetry with x_F for Xi-/Xi+. We found a qualitatively good agreement
between the model predictions and data, showing that recombination is a
competitive mechanism in the hadronization process.Comment: One reference correcte
Unitary expansion of the time evolution operator
We propose an expansion of the unitary evolution operator, associated to a
given Schr\"odinger equation, in terms of a finite product of explicit unitary
operators. In this manner, this unitary expansion can be truncated at the
desired level of approximation, as shown in the given examples.Comment: 6 pages, 7 figures. Updated version, minor final change
Quantum simulation of the Klein paradox with trapped ions
We report on quantum simulations of relativistic scattering dynamics using
trapped ions. The simulated state of a scattering particle is encoded in both
the electronic and vibrational state of an ion, representing the discrete and
continuous components of relativistic wave functions. Multiple laser fields and
an auxiliary ion simulate the dynamics generated by the Dirac equation in the
presence of a scattering potential. Measurement and reconstruction of the
particle wave packet enables a frame-by-frame visualization of the scattering
processes. By precisely engineering a range of external potentials we are able
to simulate text book relativistic scattering experiments and study Klein
tunneling in an analogue quantum simulator. We describe extensions to solve
problems that are beyond current classical computing capabilities.Comment: 3 figures, accepted for publication in PR
Klein tunneling and Dirac potentials in trapped ions
We propose the quantum simulation of the Dirac equation with potentials,
allowing the study of relativistic scaterring and the Klein tunneling. This
quantum relativistic effect permits a positive-energy Dirac particle to
propagate through a repulsive potential via the population transfer to
negative-energy components. We show how to engineer scalar, pseudoscalar, and
other potentials in the 1+1 Dirac equation by manipulating two trapped ions.
The Dirac spinor is represented by the internal states of one ion, while its
position and momentum are described by those of a collective motional mode. The
second ion is used to build the desired potentials with high spatial
resolution.Comment: 4 pages, 3 figures, minor change
Quantum Simulation of Quantum Field Theories in Trapped Ions
We propose the quantum simulation of a fermion and an antifermion field modes
interacting via a bosonic field mode, and present a possible implementation
with two trapped ions. This quantum platform allows for the scalable add-up of
bosonic and fermionic modes, and represents an avenue towards quantum
simulations of quantum field theories in perturbative and nonperturbative
regimes.Comment: To be published in Physical Review Letter
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