Hadron production from quark coalescence and jet fragmentation in intermediate energy collisions at RHIC

Transverse momentum spectra of pions, protons and antiprotons in Au+Au collisions at intermediate RHIC energy of $\sqrt{s_{NN}}=62$ GeV are studied in a model that includes both quark coalescence from the dense partonic matter and fragmentation of the quenched perturbative minijet partons. The resulting baryon to meson ratio at intermediate transverse momenta is predicted to be larger than that seen in experiments at higher center of mass energies.Comment: 6 pages, 2 figures. Figures replaced to differentially address the high-pT behavior of baryon versus antibaryon to meson ratio

Study to establish cost projections for production of Redox chemicals

A cost study of four proposed manufacturing processes for redox chemicals for the NASA REDOX Energy Storage System yielded favorable selling prices in the range $0.99 to$1.91/kg of chromic chloride, anhydrous basis, including ferrous chloride. The prices corresponded to specific energy storage costs from under $9 to$17/kWh. A refined and expanded cost analysis of the most favored process yielded a price estimate corresponding to a storage cost of $11/kWh. The findings supported the potential economic viability of the NASA REDOX system

Particle correlations at RHIC from parton coalescence dynamics -- first results

A new dynamical approach that combines covariant parton transport theory with hadronization channels via parton coalescence and fragmentation is applied to Au+Au at RHIC. Basic consequences of the simple coalescence formulas, such as elliptic flow scaling and enhanced proton/pion ratio, turn out to be rather sensitive to the spacetime aspects of coalescence dynamics.Comment: Contribution to Quark Matter 2004 (January 11-17, 2004, Oakland, CA). 4 pages, 2 EPS figs, IOP style fil

Jitter Radiation as an Alternative Mechanism for the Nonthermal X-Ray Emission of Cassiopeia A

Synchrotron radiation from relativistic electrons is usually invoked as responsible for the nonthermal emission observed in supernova remnants. Diffusive shock acceleration is the most popular mechanism to explain the process of particles acceleration and within its framework a crucial role is played by the turbulent magnetic field. However, the standard models commonly used to fit X-ray synchrotron emission do not take into account the effects of turbulence in the shape of the resulting photon spectra. An alternative mechanism that properly includes such effects is the jitter radiation, which provides for an additional power law beyond the classical synchrotron cutoff. We fitted a jitter spectral model to Chandra, NuSTAR, SWIFT/BAT, and INTEGRAL/ISGRI spectra of Cassiopeia A (Cas A) and found that it describes the X-ray soft-to-hard range better than any of the standard cutoff models. The jitter radiation allows us to measure the index of the magnetic turbulence spectrum νB and the minimum scale of the turbulence λmin across several regions of Cas A, with best-fit values νB ∼ 2 − 2.4 and λmin<∼ 100km