6,885 research outputs found
Two-particle Kapitza-Dirac diffraction
We extend the study of Kapitza-Dirac diffraction to the case of two-particle
systems. Due to the exchange effects the shape and visibility of the
two-particle detection patterns show important differences for identical and
distinguishable particles. We also identify a novel quantum statistics effect
present in momentum space for some values of the initial particle momenta,
which is associated with different numbers of photon absorptions compatible
with the final momenta.Comment: Minor changes with the published versio
The rate of synthesis and decomposition of tissue proteins in hypokinesia and increased muscular activity
During hypokinesia and physical loading (swimming) of rats, the radioactivity of skeletal muscle, liver, kidney, heart, and blood proteins was determined after administration of radioactive amino acids. Tissue protein synthesis decreased during hypokinesia, and decomposition increased. Both synthesis and decomposition increased during physical loading, but anabolic processes predominated in the total tissue balance. The weights of the animals decreased in hypokinesia and increased during increased muscle activity
The Schmidt modes of biphoton qutrits: Poincare-sphere representation
For a general-form polarization biphoton qutrit, physically corresponding to
a pair of arbitrarily polarized photons in a single frequency and wavevector
mode, we explicitly find polarization Schmidt modes. A simple method is
suggested for factorizing the state vector and the explicit expressions for the
factorizing photon creation operators are found. The degrees of entanglement
and polarization of a qutrit are shown to depend directly on the commutation
features of the factorizing operators. Clear graphic representations for the
Stokes vectors of the qutrit state as a whole, its Schmidt modes, and
factorizing single-photon creation operators are given, based on the Poincar\'e
sphere. An experimental scheme is proposed for measuring the parameters of the
Schmidt decomposition as well as for demonstrating the operational meaning of
qutrit entanglement.Comment: 20 pages, 3 figure
Computations of Three-Body Continuum Spectra
We formulate a method to solve the coordinate space Faddeev equations for
positive energies. The method employs hyperspherical coordinates and analytical
expressions for the effective potentials at large distances. Realistic
computations of the parameters of the resonances and the strength functions are
carried out for the Borromean halo nucleus 6He (n+n+alpha) for J = 0+, 0-, 1+,
1-, 2+,2-. PACS numbers: 21.45.+v, 11.80.Jy, 31.15.Ja, 21.60.GxComment: 10 pages, 3 postscript figures, LaTeX, epsf.sty, corrected misprints
in the caption of Fig.
Millennial Variability in an Idealized Ocean Model: Predicting the AMOC Regime Shifts
A salient feature of paleorecords of the last glacial interval in the North Atlantic is pronounced millennial variability, commonly known as DansgaardâOeschger events. It is believed that these events are related to variations in the Atlantic meridional overturning circulation and heat transport. Here, the authors formulate a new low-order model, based on the HowardâMalkus loop representation of ocean circulation, capable of reproducing millennial variability and its chaotic dynamics realistically. It is shown that even in this chaotic model changes in the state of the meridional overturning circulation are predictable. Accordingly, the authors define two predictive indices which give accurate predictions for the time the circulation should remain in the on phase and then stay in the subsequent off phase. These indices depend mainly on ocean stratification and describe the linear growth of small perturbations in the system. Thus, monitoring particular indices of the ocean state could help predict a potential shutdown of the overturning circulation
Classification of three-body quantum halos
The different kinds of behaviour of three-body systems in the weak binding
limit are classified with specific attention to the transition from a true
three-body system to an effective two-body system. For weakly bound Borromean
systems approaching the limit of binding we show that the size-binding energy
relation is an almost universal function of the three s-wave scattering lengths
measured in units of a hyperradial scaling parameter defined as a mass weighted
average of two-body equivalent square well radii. We explain why three-body
halos follow this curve and why systems appearing above reveal two-body
substructures. Three-body quantum halos 2-3 times larger than the limit set by
zero hypermoment are possible
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