Evaluating chiral symmetry restoration through the use of sum rules

We pursue the idea of assessing chiral restoration via in-medium modifications of hadronic spectral functions of chiral partners. The usefulness of sum rules in this endeavor is illustrated, focusing on the vector and axial-vector channels. We first present an update on constructing quantitative results for pertinent vacuum spectral functions. These spectral functions serve as a basis upon which the in-medium spectral functions can be constructed. A striking feature of our analysis of the vacuum spectral functions is the need to include excited resonances, dictated by satisfying the Weinberg-type sum rules. This includes excited states in both the vector and axial-vector channels. Preliminary results for the finite temperature vector spectral function are presented. Based on a rho spectral function tested in dilepton data which develops a shoulder at low energies, we find that the rho' peak flattens off. The flattening may be a sign of chiral restoration, though a study of the finite temperature axial-vector spectral function remains to be carried out.Comment: 9 pages, conference proceedings from Resonance Workshop at UT Austin, March 5-7 201

Dielectron Measurements in STAR

Ultrarelativistic heavy-ion collisions provide a unique environment to study the properties of strongly interacting matter. Dileptons, which are not affected by the strong interactions, are an ideal penetrating probe. We present the dielectron results for p+p and Au+Au collisions at \sqrt{s_\mathrm{NN}}} =200 GeV, as measured by the STAR experiment. We discuss the prospects of dilepton measurements with the near-future detector upgrades, and the recent lower beam energy Au+Au measurements.Comment: Resonance Workshop at UT Austin (2012), 8 pages,15 figure

Resonances and fluctuations in the statistical model

We describe how the study of resonances and fluctuations can help constrain the thermal and chemical freezeout properties of the fireball created in heavy ion collisions. This review is based on [1-5].Comment: Proceedings,"Hadronic resonance production in heavy ion and elementary collisions" UT Austin, March 5-7 201

Emergence of Skyrme crystal in Gross-Neveu and 't Hooft models at finite density

We study two-dimensional, large $N$ field theoretic models (Gross-Neveu model, 't Hooft model) at finite baryon density near the chiral limit. The same mechanism which leads to massless baryons in these models induces a breakdown of translational invariance at any finite density. In the chiral limit baryonic matter is characterized by a spatially varying chiral angle with a wave number depending only on the density. For small bare quark masses a sine-Gordon kink chain is obtained which may be regarded as simplest realization of the Skyrme crystal for nuclear matter. Characteristic differences between confining and non-confining models are pointed out.Comment: 27 pages, 11 figures, added reference, corrected sig

Neutrino Cooling of Neutron Stars. Medium effects

This review demonstrates that neutrino emission from dense hadronic component in neutron stars is subject of strong modifications due to collective effects in the nuclear matter. With the most important in-medium processes incorporated in the cooling code an overall agreement with available soft X ray data can be easily achieved. With these findings so called "standard" and "non-standard" cooling scenarios are replaced by one general "nuclear medium cooling scenario" which relates slow and rapid neutron star coolings to the star masses (interior densities). In-medium effects take important part also at early hot stage of neutron star evolution decreasing the neutrino opacity for less massive and increasing for more massive neutron stars. A formalism for calculation of neutrino radiation from nuclear matter is presented that treats on equal footing one-nucleon and multiple-nucleon processes as well as reactions with resonance bosons and condensates. Cooling history of neutron stars with quark cores is also discussed.Comment: To be published in "Physics of Neutron Star Interiors", Eds. D. Blaschke, N.K. Glendenning, A. Sedrakian, Springer, Heidelberg (2001

Velocity-space sensitivity of the time-of-flight neutron spectrometer at JET

The velocity-space sensitivities of fast-ion diagnostics are often described by so-called weight functions. Recently, we formulated weight functions showing the velocity-space sensitivity of the often dominant beam-target part of neutron energy spectra. These weight functions for neutron emission spectrometry (NES) are independent of the particular NES diagnostic. Here we apply these NES weight functions to the time-of-flight spectrometer TOFOR at JET. By taking the instrumental response function of TOFOR into account, we calculate time-of-flight NES weight functions that enable us to directly determine the velocity-space sensitivity of a given part of a measured time-of-flight spectrum from TOFOR

Relationship of edge localized mode burst times with divertor flux loop signal phase in JET

A phase relationship is identified between sequential edge localized modes (ELMs) occurrence times in a set of H-mode tokamak plasmas to the voltage measured in full flux azimuthal loops in the divertor region. We focus on plasmas in the Joint European Torus where a steady H-mode is sustained over several seconds, during which ELMs are observed in the Be II emission at the divertor. The ELMs analysed arise from intrinsic ELMing, in that there is no deliberate intent to control the ELMing process by external means. We use ELM timings derived from the Be II signal to perform direct time domain analysis of the full flux loop VLD2 and VLD3 signals, which provide a high cadence global measurement proportional to the voltage induced by changes in poloidal magnetic flux. Specifically, we examine how the time interval between pairs of successive ELMs is linked to the time-evolving phase of the full flux loop signals. Each ELM produces a clear early pulse in the full flux loop signals, whose peak time is used to condition our analysis. The arrival time of the following ELM, relative to this pulse, is found to fall into one of two categories: (i) prompt ELMs, which are directly paced by the initial response seen in the flux loop signals; and (ii) all other ELMs, which occur after the initial response of the full flux loop signals has decayed in amplitude. The times at which ELMs in category (ii) occur, relative to the first ELM of the pair, are clustered at times when the instantaneous phase of the full flux loop signal is close to its value at the time of the first ELM

New filovirus disease classification and nomenclature

Filoviruses, the members of the family Filoviridae, are currently classified into one proposed and five established genera (Supplementary Table 1). Of the twelve described filoviruses, six have been identified as aetiological agents of naturally occurring human disease outbreaks