Cross sections for pentaquark baryon production from protons in reactions induced by hadrons and photons

Using hadronic Lagrangians that include the interaction of pentaquark $\Theta^+$ baryon with $K$ and $N$, we evaluate the cross sections for its production from meson-proton, proton-proton, and photon-proton reactions near threshold. With empirical coupling constants and form factors, the predicted cross sections are about 1.5 mb in kaon-proton reactions, 0.1 mb in rho-nucleon reactions, 0.05 mb in pion-nucleon reactions, 20 $\mu$b in proton-proton reactions, and 40 nb in photon-proton reactions.Comment: 14 pages, 7 figure

Development of laser guided deep-hole measurement system: adjustment to a smaller size hole

Deep holes are bored with the meter, millimeter, and micrometer level diameters in engineering. Examples of such holes with large 100-millimeter-level diameters and meter-level lengths are the rotation shafts of jet engines, generators and cannons. Holes with normal 10-millimeter-level diameters and lengths of several hundred millimeters are used for the main spindles of machines, the small cylinder in plastic injection molding, the tube sheet for heat exchanger, and guns. To measure such components the proposed measurement system consists of a measurement head in order to scan hole wall, a laser interferometer for measuring surface parameters of the hole and an optical device at the backside for detecting attitude of the measurement head. As a result of experimental analysis, it is observed that deephole having small diameter and longlength can be measured automatically by the new developed measurement system

Particle acceleration and the origin of gamma-ray emission from Fermi Bubbles

Fermi LAT has discovered two extended gamma-ray bubbles above and below the galactic plane. We propose that their origin is due to the energy release in the Galactic center (GC) as a result of quasi-periodic star accretion onto the central black hole. Shocks generated by these processes propagate into the Galactic halo and accelerate particles there. We show that electrons accelerated up to ~10 TeV may be responsible for the observed gamma-ray emission of the bubbles as a result of inverse Compton (IC) scattering on the relic photons. We also suggest that the Bubble could generate the flux of CR protons at energies > 10^15 eV because the shocks in the Bubble have much larger length scales and longer lifetimes in comparison with those in SNRs. This may explain the the CR spectrum above the knee.Comment: 5 pages, 4 figures. Expanded version of the contribution to the 32nd ICRC, Beijing, #0589. To appear in the proceeding

The atmospheric effects of stratospheric aircraft: A current consensus

In the early 1970's, a fleet of supersonic aircraft flying in the lower stratosphere was proposed. A large fleet was never built for economic, political, and environmental reasons. Technological improvements may make it economically feasible to develop supersonic aircraft for current markets. Some key results of earlier scientific programs designed to assess the impact of aircraft emissions on stratospheric ozone are reviewed, and factors that must be considered to assess the environmental impact of aircraft exhaust are discussed. These include the amount of nitrogen oxides injected in the stratosphere, horizontal transport, and stratosphere/troposphere assessment models are presented. Areas in which improvements in scientific understanding and model representation must be made to reduce the uncertainty in model calculations are identified

Correlation between ocular elasticity and intraocular pressure on optic nerve damages

Optic neuropathy in glaucoma causes visual field loss and blindness [1]. The optic nerve damage in the lamina cribrosa (LC) of the sclera, the primary site of glaucoma, is correlated with the intraocular pressure (IOP) [2]. Literature shows that the optic nerves are sheared at high IOP and the scleral biomechanical properties play an important role in the development and progression of glaucomatous damage to the LC and ganglion cell axons with the optic nerve head (ONH). The aim of this study is to determine and characterize the correlation between the corneal, scleral and ONH elasticity, and intraocular pressure on the optic nerve damages

Correlation between ocular elasticity and intraocular pressure on optic nerve damages

Optic neuropathy in glaucoma causes visual field loss and blindness [1]. The optic nerve damage in the lamina cribrosa (LC) of the sclera, the primary site of glaucoma, is correlated with the intraocular pressure (IOP) [2]. Literature shows that the optic nerves are sheared at high IOP and the scleral biomechanical properties play an important role in the development and progression of glaucomatous damage to the LC and ganglion cell axons with the optic nerve head (ONH). The aim of this study is to determine and characterize the correlation between the corneal, scleral and ONH elasticity, and intraocular pressure on the optic nerve damages

Color-octet mechanism and J/psi polarization at LEP

Polarized heavy quarkonium productions in $Z^0$ decays are considered. We find that polarizations of the produced quarkonia are independent of that of the parent Z^0 provided that one considers the energy distribution or the total production rate. Produced J/psi's via the color-octet and the color- singlet mechanisms are expected to be 19% and 29% longitudinally polarized, respectively. The energy dependence of eta_{1,8}(x)=\frac{dGamma_{1,8}^L}{dx} /\frac{dGamma_{1,8}}{d x} is very sensitive to the production mechanism, and therefore the measurement of \eta(x)_exp will be an independent probe of the color-octet mechanism.Comment: 15 pages, minor changes, version to be published in Phys. Rev.

Resonance Model of πΔ→YK\pi \Delta \rightarrow Y K for Kaon Production in Heavy Ion Collisions

The elementary production cross sections $\pi \Delta \rightarrow Y K$ $(Y=\Sigma,\,\, \Lambda)$ and $\pi N \rightarrow Y K$ are needed to describe kaon production in heavy ion collisions. The $\pi N \rightarrow Y K$ reactions were studied previously by a resonance model. The model can explain the experimental data quite well \cite{tsu}. In this article, the total cross sections $\pi \Delta \rightarrow Y K$ at intermediate energies (from the kaon production threshold to3 GeV of $\pi \Delta$ center-of-mass energy) are calculated for the first time using the same resonance model. The resonances, $N(1710)\,I(J^P) = \frac{1}{2}(\frac{1}{2}^+)$ and $N(1720)\, \frac{1}{2} (\frac{3}{2}^+)$ for the $\pi \Delta \rightarrow \Sigma K$ reactions, and $N(1650)\, \frac{1}{2} (\frac{1}{2}^-)$, $N(1710)\, \frac{1}{2} (\frac{1}{2}^+)$ and $N(1720)\, \frac{1}{2} (\frac{3}{2}^+)$ for the $\pi \Delta \rightarrow \Lambda K$ reactions are taken into account coherently as the intermediate states in the calculations. Also t-channel $K^*(892) \frac{1}{2}(1^-)$ vector meson exchange is included. The results show that $K^*(892)$ exchange is neglegible for the $\pi \Delta \rightarrow \Sigma K$ reactions, whereas this meson does not contribute to the $\pi \Delta \rightarrow \Lambda K$ reactions. Furthemore, the $\pi \Delta \rightarrow Y K$ contributions to kaon production in heavy ion collisions are not only non-neglegible but also very different from the $\pi N \rightarrow Y K$ reactions. An argument valid for $\pi N \rightarrow Y K$ cannot be extended to $\pi \Delta \rightarrow Y K$ reactions. Therefore, cross sections for $\pi \Delta \rightarrow Y K$ including correctly the different isospins must beComment: ( Replaced with corrections of printing errors in the Table. ) 15 pages, Latex file with 4 figures, 1 figure is included in the text. A compressed uuencode file for 3 figures is appended. (A figure file format was changed.) Also available upon reques