Energy weighted sum rules for mesons in hot and dense matter

We study energy weighted sum rules of the pion and kaon propagator in nuclear matter at finite temperature. The sum rules are obtained from matching the Dyson form of the meson propagator with its spectral Lehmann representation at low and high energies. We calculate the sum rules for specific models of the kaon and pion self-energy. The in-medium spectral densities of the K and anti-K mesons are obtained from a chiral unitary approach in coupled channels which incorporates the S- and P-waves of the kaon-nucleon interaction. The pion self-energy is determined from the P-wave coupling to particle-hole and Delta-hole excitations, modified by short range correlations. The sum rules for the lower energy weights are fulfilled satisfactorily and reflect the contributions from the different quasi-particle and collective modes of the meson spectral function. We discuss the sensitivity of the sum rules to the distribution of spectral strength and their usefulness as quality tests of model calculations.Comment: 19 pages, 6 figures; one figure added, enhanced discussion, version to appear in PR

Evershed clouds as precursors of moving magnetic features around sunspots

The relation between the Evershed flow and moving magnetic features (MMFs) is studied using high-cadence, simultaneous spectropolarimetric measurements of a sunspot in visible (630.2 nm) and near-infrared (1565 nm) lines. Doppler velocities, magnetograms, and total linear polarization maps are calculated from the observed Stokes profiles. We follow the temporal evolution of two Evershed clouds that move radially outward along the same penumbral filament. Eventually, the clouds cross the visible border of the spot and enter the moat region, where they become MMFs. The flux patch farther from the sunspot has the same polarity of the spot, while the MMF closer to it has opposite polarity and exhibits abnormal circular polarization profiles. Our results provide strong evidence that at least some MMFs are the continuation of the penumbral Evershed flow into the moat. This, in turn, suggests that MMFs are magnetically connected to sunspots.Comment: To appear in ApJ Letters, Vol 649, 2006 September 20 issu

Rotating Superconductors and the London Moment: Thermodynamics versus Microscopics

Comparing various microscopic theories of rotating superconductors to the conclusions of thermodynamic considerations, we traced their marked difference to the question of how some thermodynamic quantities (the electrostatic and chemical potentials) are related to more microscopic ones: The electron's the work function, mean-field potential and Fermi energy -- certainly a question of general import. After the correct identification is established, the relativistic correction for the London Moment is shown to vanish, with the obvious contribution from the Fermi velocity being compensated by other contributions such as electrostatics and interactions.Comment: 23 pages 4 fi

Management of septic shock: a protocol-less approach

Citation\ud ProCESS Investigators, Yealy DM, Kellum JA, Huang DT, Barnato AE, Weissfeld LA, Pike F, Terndrup T, Wang HE, Hou PC, LoVecchio F, Filbin MR, Shapiro NI, Angus DC. A randomized trial of protocol-based care for early septic shock. N Engl J Med. 2014; 370:1683–93.\ud \ud Background\ud In a single-center study published more than a decade ago involving patients presenting to the emergency department with severe sepsis and septic shock, mortality was markedly lower among those who were treated according to a 6-h protocol of early goal-directed therapy (EGDT), in which intravenous fluids, vasopressors, inotropes, and blood transfusions were adjusted to reach central hemodynamic targets including central venous pressure, central venous oxygen saturation, and indirect estimates of cardiac output, than among those receiving usual care.\ud \ud Methods\ud Objective: The objective was to determine whether these EGDT findings were generalizable and whether all aspects of the EGDT protocol were necessary to achieve those outcomes.\ud \ud Design: A multicenter randomized three-arm controlled trial.\ud \ud Setting: Thirty-one academic emergency departments in the United States.\ud \ud Subjects: Patients older than 18 years of age presenting to the emergency department with septic shock.\ud \ud Intervention: Patients were assigned to one of three groups for 6 h of resuscitation: protocol-based EGDT as defined by River and colleagues; protocol-based standard therapy that did not require the placement of a central venous catheter, administration of inotropes, or blood transfusions; and usual care which mandated no specific monitoring or management approaches.\ud \ud Outcomes: The primary end point was 60-day in-hospital mortality. Also tested sequentially was whether protocol-based care (EGDT and standard therapy groups combined) was superior to usual care and whether protocol-based EGDT was superior to protocol-based standard therapy. Secondary outcomes included longer-term mortality and the need for organ support.\ud \ud Results\ud A total of 1,351 patients were enrolled, of whom 1,341 were evaluable due to patient/family request: 439 were randomly assigned to protocol-based EGDT, 446 to protocol-based standard therapy, and 456 to usual care. Resuscitation strategies differed significantly with respect to the monitoring of central venous pressure and central venous oxygen and the use of intravenous fluids, vasopressors, inotropes, and blood transfusions. By 60 days, there were 92 deaths in the protocol-based EGDT group (21.0 %), 81 in the protocol-based standard therapy group (18.2 %), and 86 in the usual care group (18.9 %) (relative risk with protocol-based therapy versus usual care, 1.04; 95 % confidence interval, 0.82 to 1.31; P = 0.83; relative risk with protocol-based EGDT versus protocol-based standard therapy, 1.15; 95 % CI, 0.88 to 1.51; P = 0.31). There were no significant differences in 90-day mortality, 1-year mortality, or the need for organ support.\ud \ud Conclusions\ud In a multicenter trial conducted in the tertiary care setting, protocol-based resuscitation of patients in whom septic shock was diagnosed in the emergency department did not improve outcomes

Strange and charm mesons at FAIR

We study the properties of strange and charm mesons in hot and dense matter within a self-consistent coupled-channel approach for the experimental conditions of density and temperature expected for the CBM experiment at FAIR/GSI. The in-medium solution at finite temperature accounts for Pauli blocking effects, mean-field binding of all the baryons involved, and meson self-energies. We analyze the behaviour in this hot and dense environment of dynamically-generated baryonic resonances together with the evolution with density and temperature of the strange and open-charm meson spectral functions. We test the spectral functions for strange mesons using energy-weighted sum rules and finally discuss the implications of the properties of charm mesons on the D_{s0}(2317) and the predicted X(3700) scalar resonances.Comment: 12 pages, 9 figures, invited talk at XXXI Mazurian Lakes Conference on Physics: Nuclear Physics and the Road to FAIR, August 30-September 6, 2009, Piaski, Polan

The a1(1260) as a rho pi resonance in nuclear matter

We present a theoretical study of the properties of the a1(1260) axial-vector resonance in a cold nuclear medium. In the vacuum, the a1(1260) resonance is generated dynamically from the interactions of a pseudoscalar and vector meson (rho pi and K barK*) in a coupled channel chiral unitary approach. Medium effects are implemented through the modification of the rho and pi propagators at finite nuclear density from well established microscopic many-body calculations. The in-medium pion spectral function accounts for the coupling to N-hole and Delta-hole excitations including short range correlations, whereas the in-medium rho incorporates modifications of its virtual pion cloud as well as direct resonance-hole excitations. The resulting in-medium a1(1260) exhibits significant broadening with increasing density as reflected in the rho pi scattering amplitude. The possible relation of our results with partial restoration of chiral symmetry in nuclear matter is discussed in terms of in-medium Weinberg sum rules.Comment: 22 pages, 9 figures, PTPTE

Tricyclazole-clay complexes as potential smart delivery systems: release in water and environmental fate in alluvial and sandy soils

Natural mineral clays (SWy-2, CTI and SH) were modified with natural inorganic cation (Fe3+) and the biopolymer (chitosan (ch)) to increase the adsorption capacity for tricyclazole. Three ways to prepare tricyclazole-clay complexes (ground mixing, GM, weak complex, WC and strong complex, SC) were assayed with the aim to develop possible components for controlled release formulations (CRFs) of this fungicide. The greatest adsorption (> 93%) was measured in the natural clays modified with Fe3+. The release of tricyclazole in water was higher for GMs of SWch6 (77%), SWch4 (84%) and CTIFe (85%). No significant differences were observed in the dissipation in soil of tricyclazole applied as commercial product or as formulation. However, the leaching of the fungicide depended on the type of soil: tricyclazole was not detected in any leachate from the soil with higher clay content (alluvial) whereas the SWch6 weak complex (WC) reduced the leaching of tricyclazole (65%) as compared to the commercial formulation (75%) in a sandy soil after 60 days. This last tricyclazol-clay complex could be considered as appropriate component for CRF, to be used in sandy soils. The other modified clays assayed, showing very high, strong and irreversible adsorption could find application as filters to eliminate tricyclazole from contaminated waters. Clay-fungicide interaction mechanisms are discussed and related to their soil and water behavior.CSIC (JAE-Doc program), MINECO (AGL2011-23779 project) and Junta de Andalucía (P11-AGR-7400), co-funded by EU FEDER-FSE (OP 2009-2013) funding.Peer Reviewe

Competition between the Modulation Instability and Stimulated Brillouin Scattering in a Broadband Slow Light Device

We observe competition between the modulation instability (MI) and stimulated Brillouin scattering (SBS) in a 9.2-GHz broadband SBS slow light device, in which a standard 20-km-long single-mode LEAF fibre is used as the SBS medium. We find that MI is dominant and depletes most of the pump power when we use an intense pump beam at ~1.55 {\mu}m, where the LEAF fibre is anomalously dispersive. The dominance of the MI in the LEAF-fibre-based system suppresses the SBS gain, degrading the SBS slow light delay and limiting the SBS gain-bandwidth to 126 dB \cdot GHz. In a dispersion-shifted highly nonlinear fibre, the SBS slow light delay is improved due to the suppression of the MI, resulting in a gain-bandwidth product of 344 dB \cdot GHz, limited by our available pump power of 0.82 W