Glueball enhancement by color de-confinement

High energy heavy ion collisions lead to the formation of a strong coupling de-confined phase in which the lightest glueballs are numerous and stable. We analyze how their properties manifest themselves in experimental spectra and show that they provide a good signature for color de-confinement.Comment: 9 pages, 4 figure

eta - eta' - glueball mixing

We have revisited glueball mixing with the pseudoscalar mesons in the MIT bag model scheme. The calculation has been performed in the spherical cavity approximation to the bag using two different fermion propagators, the cavity and the free propagators. We obtain a very small probability of mixing for the eta at the level of $0.04-0.1% and a bigger for the eta' at the level of 4-12%. Our results differ from previous calculations in the same scheme but seem to agree with the experimental analysis. We discuss the origin of our difference which stems from the treatment of our time integrations.Comment: 21 pages, 7 figure

The COLD-SAT Experiment for Cryogenic Fluid Management Technology

Future national space transportation missions will depend on the use of cryogenic fluid management technology development needs for these missions. In-space testing will be conducted in order to show low gravity cryogenic fluid management concepts and to acquire a technical data base. Liquid H2 is the preferred test fluid due to its propellant use. The design of COLD-SAT (Cryogenic On-orbit Liquid Depot Storage, Acquisition, and Transfer Satellite), an Expendable Launch Vehicle (ELV) launched orbital spacecraft that will perform subcritical liquid H2 storage and transfer experiments under low gravity conditions is studied. An Atlas launch vehicle will place COLD-SAT into a circular orbit, and the 3-axis controlled spacecraft bus will provide electric power, experiment control, and data management, attitude control, and propulsive accelerations for the experiments. Low levels of acceleration will provide data on the effects that low gravity might have on the heat and mass transfer processes used. The experiment module will contain 3 liquid H2 tanks; fluid transfer, pressurization and venting equipment; and instrumentation

The Gluon Spin in the Chiral Bag Model

We study the gluon polarization contribution at the quark model renormalization scale to the proton spin, $\Gamma$, in the chiral bag model. It is evaluated by taking the expectation value of the forward matrix element of a local gluon operator in the axial gauge $A^+=0$. It is shown that the confining boundary condition for the color electric field plays an important role. When a solution satisfying the boundary condition for the color electric field, which is not the conventionally used but which we favor, is used, the $\Gamma$ has a positive value for {\it all} bag radii and its magnitude is comparable to the quark spin polarization. This results in a significant reduction in the relative fraction of the proton spin carried by the quark spin, which is consistent with the small flavor singlet axial current measured in the EMC experiments.Comment: Corrections to figure

The solid surface combustion space shuttle experiment hardware description and ground-based test results

The Lewis Research Center is developing a series of microgravity combustion experiments for the Space Shuttle. The Solid Surface Combustion Experiment (SSCE) is the first to be completed. SSCE will study flame spreading over thermally thin fuels (ashless filter paper) under microgravity conditions. The flight hardware consists of a combustion chamber containing the sample and a computer which takes the data and controls the experiment. Experimental data will include gas-phase and solid-phase temperature measurements and motion pictures of the combustion process. Flame spread rates will be determined from the motion pictures

Hidden Dirac Monopoles

Dirac showed that the existence of one magnetic pole in the universe could offer an explanation of the discrete nature of the electric charge. Magnetic poles appear naturally in most grand unified theories. Their discovery would be of greatest importance for particle physics and cosmology. The intense experimental search carried thus far has not met with success. I proposed a universe with magnetic poles which are not observed free because they hide in deeply bound monopole--anti-monopole states named monopolium. I discuss the realization of this proposal and its consistency with known cosmological features. I furthermore analyze its implications and the experimental signatures that confirm the scenario.Comment: Comments: 15 pages, 3 figure

Relativity and constituent quark structure in model calculations of parton distributions

According to recent studies, Parton Distribution Functions (PDFs) and Generalized Parton Distributions (GPDs) can be evaluated in a Constituent Quark Model (CQM) scenario, considering the constituent quarks as composite objects. In here, a fully covariant model for a system of two particles, together with its non relativistic limit, are used to calculate PDFs and GPDs. The analysis permits to realize that by no means the effects of Relativity can be simulated taking into account the structure of the constituent particles, the two effects being independent and necessary for a proper description of available high energy data in terms of CQM

A Comparison of Electron Transport Rate, Photosynthetically Active Radiation, Light-Adapted Fluorescence, and Dark-Adapted Fluorescence Between Stipa pulchra and Pennisetium setaceum

The purpose of this investigation was to provide an explanation into how the invasive species Pennisetium setaceum, Fountain Grass, is able to outcompete the native California grassland species Stipa pulchra, Purple Needle Grass. We used a light adapted and a dark adapted fluorometer to measure the photosynthetic radiation (PAR), leaf temperature, alpha (α), light adapted fluorescence (Fv’/Fm’), dark adapted fluorescence (Fv/Fm), and the electron transport rate (ETR) on young Fountain Grass and Purple Needlegrass. After collecting and analyzing the data, we concluded that the dark adapted fluorescence (Fv/Fm) was the only statistically significant measurement where the Fv/Fm of S. pulchra is higher than that of P. setaceum which suggests that S. pulchra’s quantum yield of photosystem II is higher and is therefore more efficient. With this result, we are able to state that Fv/Fm is not the reason why Fountain Grass outcompetes Purple Needlegrass