Finite resolution measurement of the non-classical polarization statistics of entangled photon pairs

By limiting the resolution of quantum measurements, the measurement induced changes of the quantum state can be reduced, permitting subsequent measurements of variables that do not commute with the initially measured property. It is then possible to experimentally determine correlations between non-commuting variables. The application of this method to the polarization statistics of entangled photon pairs reveals that negative conditional probabilities between non-orthogonal polarization components are responsible for the violation of Bell's inequalities. Such negative probabilities can also be observed in finite resolution measurements of the polarization of a single photon. The violation of Bell's inequalities therefore originates from local properties of the quantum statistics of single photon polarization.Comment: 15 pages, 5 figures and 1 table, new figure to illustrate results, improved explanation of statistical analysi

Statistical fluctuations for the fission process on its decent from saddle to scission

We reconsider the importance of statistical fluctuations for fission dynamics beyond the saddle in the light of recent evaluations of transport coefficients for average motion. The size of these fluctuations are estimated by means of the Kramers-Ingold solution for the inverted oscillator, which allows for an inclusion of quantum effects.Comment: 12 pages, Latex, 5 Postscript figures; submitted to PRC e-mail: [email protected] www home page: http://www.physik.tu-muenchen.de/tumphy/e/T36/hofmann.htm

Formation of small-scale structure in SUSY CDM

The lightest supersymmetric particle, most likely the lightest neutralino, is one of the most prominent particle candidates for cold dark matter (CDM). We show that the primordial spectrum of density fluctuations in neutralino CDM has a sharp cut-off, induced by two different damping mechanisms. During the kinetic decoupling of neutralinos, non-equilibrium processes constitute viscosity effects, which damp or even absorb density perturbations in CDM. After the last scattering of neutralinos, free streaming induces neutralino flows from overdense to underdense regions of space. Both damping mechanisms together define a minimal mass scale for perturbations in neutralino CDM, before the inhomogeneities enter the nonlinear epoch of structure formation. We find that the very first gravitationally bound neutralino clouds ought to have masses above 10^{-6} solar masses, which is six orders of magnitude above the mass of possible axion miniclusters.Comment: 7 pages, 3 figures, to appear in proceedings of "IDM 2002, 4th International Workshop on the Identification of Dark Matter

Nuclear fission: The "onset of dissipation" from a microscopic point of view

Semi-analytical expressions are suggested for the temperature dependence of those combinations of transport coefficients which govern the fission process. This is based on experience with numerical calculations within the linear response approach and the locally harmonic approximation. A reduced version of the latter is seen to comply with Kramers' simplified picture of fission. It is argued that for variable inertia his formula has to be generalized, as already required by the need that for overdamped motion the inertia must not appear at all. This situation may already occur above T=2 MeV, where the rate is determined by the Smoluchowski equation. Consequently, comparison with experimental results do not give information on the effective damping rate, as often claimed, but on a special combination of local stiffnesses and the friction coefficient calculated at the barrier.Comment: 31 pages, LaTex, 9 postscript figures; final, more concise version, accepted for publication in PRC, with new arguments about the T-dependence of the inertia; e-mail: [email protected]

Optimized phase switching using a single atom nonlinearity

We show that a nonlinear phase shift of pi can be obtained by using a single two level atom in a one sided cavity with negligible losses. This result implies that the use of a one sided cavity can significantly improve the pi/18 phase shift previously observed by Turchette et al. [Phys. Rev. Lett. 75, 4710 (1995)].Comment: 6 pages, 3 figures, added comments on derivation and assumption

Alpha-decay chains of 173288115^{288}_{173}115 and 172287115^{287}_{172}115 in the Relativistic Mean Field theory

In the recent experiments designed to synthesize the element 115 in the $^{243}$Am+$^{48}$Ca reaction at Dubna in Russia, three similar decay chains consisting of five consecutive $\alpha$-decays, and another different decay chain of four consecutive $\alpha$-decays are detected, and the decay properties of these synthesized nuclei are claimed to be consistent with consecutive $\alpha$-decays originating from the parent isotopes of the new element 115, $^{288}115$ and $^{287}115$, respectively\cite{ogan.03}. Here in the present work, the recently developed deformed RMF+BCS method with a density-independent delta-function interaction in the pairing channel is applied to the analysis of these newly synthesized superheavy nuclei $^{288}115$, $^{287}115$, and their $\alpha$-decay daughter nuclei. The calculated $\alpha$-decay energies and half-lives agree well with the experimental values and with those of the macroscopic-microscopic FRDM+FY and YPE+WS models. In the mean field Lagrangian, the TMA parameter set is used. Particular emphasis is paid on the influence to both the ground-state properties and energy surfaces introduced by different treatments of pairing. Two different effective interactions in the particle-particle channel, i.e., the constant pairing and the density-independent delta-function interaction, together with the blocking effect are discussed in detail.Comment: 17 pages, 5 figure