Reconstructing ρ0\rho^0 and ω\omega mesons from non-leptonic decays in C+C at 2AGeV

We predict transverse and longitudinal momentum spectra and yields of $\rho^0$ and $\omega$ mesons reconstructed from hadron correlations in C+C reactions at 2~AGeV. The rapidity and $p_T$ distributions for reconstructable $\rho^0$ mesons differs strongly from the primary distribution, while the $\omega$'s distributions are only weakly modified. We discuss the temporal and spatial distributions of the particles emitted in the hadron channel. Finally, we report on the mass shift of the $\rho^0$ due to its coupling to the $N^*(1520)$, which is observable in both the di-lepton and $\pi\pi$ channel. Our calculations can be tested with the Hades experiment at GSI, Darmstadt

Optimal Squeezing in Resonance Fluorescence via Atomic-State Purification

Squeezing of atomic resonance fluorescence is shown to be optimized by a properly designed environment, which can be realized by a quasi-resonant cavity. Optimal squeezing is achieved if the atomic coherence is maximized, corresponding to a pure atomic quantum state. The atomic-state purification is achieved by the backaction of the cavity field on the atom, which increases the atomic coherence and decreases the atomic excitation. For realistic cavities, the coupling of the atom to the cavity field yields a purity of the atomic state of more than 99%. The fragility of squeezing against dephasing is substantially reduced in this scenario, which may be important for various applications.Comment: 6 pages including supplemental information, 3 figures. Accepted for PR

Radio Observations of AGN in Low Surface Brightness Galaxies

We present preliminary results of a study of the low frequency radio continuum emission from the nuclei of Giant Low Surface Brightness (LSB) galaxies. We have mapped the emission and searched for extended features such as radio lobes/jets associated with AGN activity. LSB galaxies are poor in star formation and generally less evolved compared to nearby bright spirals. This paper presents low frequency observations of 3 galaxies; PGC 045080 at 1.4 GHz, 610 MHz, 325MHz, UGC 1922 at 610 MHz and UGC 6614 at 610 MHz. The observations were done with the GMRT. Radio cores as well as extended structures were detected and mapped in all three galaxies; the extended emission may be assocated with jets/lobes associated with AGN activity. Our results indicate that although these galaxies are optically dim, their nuclei can host AGN that are bright in the radio domain.Comment: To appear in proceedings IAU Symp 244, 'Dark Galaxies and Lost Baryons', June 2007, 2 pages including 1 figur

2H and 13C NMR studies on the temperature-dependent water and protein dynamics in hydrated elastin, myoglobin and collagen

2H NMR spin-lattice relaxation and line-shape analyses are performed to study the temperature-dependent dynamics of water in the hydration shells of myoglobin, elastin, and collagen

Atomic screening of nuclear transitions

In the analysis of time-reversal and Mössbauer absorption experiments, it is important to consider atomic processes which interfere with the direct nuclear transition. Interaction of the photon with the atomic electrons causes the radiation to acquire a phase shift, specified by the interference parameter ξ(L_π). We present theoretical expressions for ξ and compare our calculated values with experiment. Satisfactory agreement is obtained. In particular, an apparent violation of time-reversal invariance in the 129-keV transition of ^(191)Ir is fully explained by these effects

How ripples turn into dots: modeling ion-beam erosion under oblique incidence

Pattern formation on semiconductor surfaces induced by low energetic ion-beam erosion under normal and oblique incidence is theoretically investigated using a continuum model in form of a stochastic, nonlocal, anisotropic Kuramoto-Sivashinsky equation. Depending on the size of the parameters this model exhibits hexagonally ordered dot, ripple, less regular and even rather smooth patterns. We investigate the transitional behavior between such states and suggest how transitions can be experimentally detected.Comment: 11 pages, 4 figures, submitted for publication, revised versio

True photo-counting statistics of multiple on-off detectors

We derive a closed photo-counting formula, including noise counts and a finite quantum efficiency, for photon number resolving detectors based on on-off detectors. It applies to detection schemes such as array detectors and multiplexing setups. The result renders it possible to compare the corresponding measured counting statistics with the true photon number statistics of arbitrary quantum states. The photo-counting formula is applied to the discrimination of photon numbers of Fock states, squeezed states, and odd coherent states. It is illustrated for coherent states that our formula is indispensable for the correct interpretation of quantum effects observed with such devices.Comment: 7 pages, 4 figure