In-medium properties of D-mesons at FAIR

We obtain the D-meson spectral density at finite temperature for the conditions of density and temperature expected at FAIR. We perform a self-consistent coupled-channel calculation taking, as a bare interaction, a separable potential model. The $\Lambda_c$ (2593) resonance is generated dynamically. We observe that the D-meson spectral density develops a sizeable width while the quasiparticle peak stays close to the free position. The consequences for the D-meson production at FAIR are discussed.Comment: 4 pages, 3 figures, to appear in the proceedings of 9th International Conference on Hypernuclear and Strange Particle Physics (HYP2006), Mainz (Germany), 10-14 October 200

Wave-coupled LiNbO_3 electrooptic modulator for microwave and millimeter-wave modulation

A new technique of phase velocity matching in electrooptic modulators was demonstrated. The results show that the phase velocity mismatch due to material dispersion in traveling-wave LiNbO_3 optical waveguide modulators can be greatly reduced by breaking the modulation transmission line into short segments and connecting each segment to its own surface dipole antenna. The array of antennas is then illuminated by the modulation signal from below at the proper angle to produce a delay from antenna to antenna that matches the optical waveguide's delay. A phase modulator 25 mm in length with five antennas and five transmission line segments was operated from 4.6 to 13 GHz with a maximum phase modulation sensitivity of over 100°/W^(1/2)

Observation Of Turbulent Intermittency Scaling With Magnetic Helicity In An MHD Plasma Wind Tunnel

The intermittency in turbulent magnetic field fluctuations has been observed to scale with the amount of magnetic helicity injected into a laboratory plasma. An unstable spheromak injected into the MHD wind tunnel of the Swarthmore Spheromak Experiment displays turbulent magnetic and plasma fluctuations as it relaxes into a Taylor state. The level of intermittency of this turbulence is determined by finding the flatness of the probability distribution function of increments for magnetic pickup coil fluctuations B(t). The intermittency increases with the injected helicity, but spectral indices are unaffected by this variation. While evidence is provided which supports the hypothesis that current sheets and reconnection sites are related to the generation of this intermittent signal, the true nature of the observed intermittency remains unknown

Critical Review Of Quark Gluon Plasma Signals

Compelling evidence for a new form of matter has been claimed to be formed in Pb+Pb collisions at SPS. We critically review two suggested signatures for this new state of matter: First the suppression of the J/$\Psi$, which should be strongly suppressed in the QGP by two different mechanisms, the color-screening and the QCD-photoeffect. Secondly the measured particle, in particular strange hadronic, ratios might signal the freeze-out from a quark-gluon phase.Comment: 7 pages 6 figures, Contribution to the Proceedings of CRIS 2000, 3rd Catania Relativistic Ion Studies, Acicastello, Italy, May 22-26, 200

Open-charm enhancement at FAIR?

We have calculated the D-meson spectral density at finite temperature within a self-consistent coupled-channel approach that generates dynamically the $\Lambda_c$ (2593) resonance. We find a small mass shift for the D-meson in this hot and dense medium while the spectral density develops a sizeable width. The reduced attraction felt by the D-meson in hot and dense matter together with the large width observed have important consequences for the D-meson production in the future CBM experiment at FAIR.Comment: 4 pages, 2 figures, to appear in the proceedings of 9th International Conference on Strangeness in Quark Matter (SQM2006), Los Angeles, USA, March 26-31, 200

Hyperons and massive neutron stars: vector repulsion and SU(3) symmetry

With the discovery of massive neutron stars such as PSR J1614-2230, the question has arisen whether exotic matter such as hyperons can exist in the neutron star core. We examine the conditions under which hyperons can exist in massive neutron stars. We consistently investigate the vector meson-hyperon coupling, going from SU(6) quark model to a broader SU(3) symmetry. We propose that the maximum neutron star mass decreases linearly with the strangeness content f_s of the neutron star core as M_max(f_s) = M_max(0) - 0.6 M_solar (f_s/0.1), which seems to be independent of the underlying nuclear equation of state and the vector baryon-meson coupling scheme. Thus, pulsar mass measurements can be used to constrain the hyperon fraction in neutron stars.Comment: 13 pages, 10 figure

A Preliminary List of the Haliplidae Known to Occur in Iowa

The family of Coleoptera known as Haliplidae or the Crawling Water Beetles includes small sized beetles that may be readily recognized by the oval shape and the ten segmented filiform antennae. They are usually light brown or yellow, spotted with black, in color. The elytra have rows of punctures and are widest near the front

Properties of Exotic Matter for Heavy Ion Searches

We examine the properties of both forms of strange matter, small lumps of strange quark matter (strangelets) and of strange hadronic matter (Metastable Exotic Multihypernuclear Objects: MEMOs) and their relevance for present and future heavy ion searches. The strong and weak decays are discussed separately to distinguish between long-lived and short-lived candidates where the former ones are detectable in present heavy ion experiments while the latter ones in future heavy ion experiments, respectively. We find some long-lived strangelet candidates which are highly negatively charged with a mass to charge ratio like a anti deuteron (M/Z=-2) but masses of A=10 to 16. We predict also many short-lived candidates, both in quark and in hadronic form, which can be highly charged. Purely hyperonic nuclei are bound and have a negative charge while carrying a positive baryon number. We demonstrate also that multiply charmed exotics (charmlets) might be bound and can be produced at future heavy ion colliders.Comment: 10 pages, 4 figures, uses IOP style and epsf.sty, to be published in Journal of Physics, Proceedings of the International Symposium on Strangeness in Quark Matter 1997, April 14-18, Thera (Santorini), Hellas. Corrected typos, added comment about bag constant