The many sources effect on the genuine multihadron correlations

Here we report on a study aimed to explore the dependence of the genuine multiparticle correlations on the number of sources while the influence of other possible factors affecting the multihadron production is avoided. The analysis utilised the normalised cumulants, calculated in three-dimensional phase space, of the reaction e+e- -> Z -> hadrons using a large Monte Carlo event sample. The multi-sources reactions were simulated by overlaying a few independent single e+e- annihilation events. It was found that as the number of sources S increases, the cumulants do not change significantly their structure, but those of an order q>2 (i.e. more than 2 pions) decrease fast in their magnitude. This reduction can be understood in termsof combinatorial considerations of source mixing which dilutes the correlations by a factor of about 1/S^{q-1} which can also serve as a method to estimated the number of sources. This expected suppression is well reproduced by recent cumulant measurements in hadron and nucleus induced reactions both in one (rapidity) and two (rapidity vs. azimuthal angle) dimensions. The diminishing genuine correlations effect should also appear in other dynamical correlations like the Bose-Einstein in e+e- -> W+W- -> hadrons and in nucleus-nucleus reactions.Comment: 12 pages, 4 figs. Invited talk presented by G. Alexander at the 9th International Workshop on Multiparticle Production: New Frontiers in Soft Physics and Correlations on the Threshold of the Third Millenium, Turin, Italy, June 12 - 17, 200

A Window to the Past

Lenin promised peace to the Russian people, but it was an illusion that never came, for the country where my great-grandfather remained with the majority of my family soon sunk into civil war. Krista Adamovich: When I was a child, my family and I would make the trek to my grandparents\u27 house in Yonkers to celebrate mass with them once a month. I remember always dreading sitting in that uncomfortable pew listening to a priest speak the Russian language that I knew so little of. I never told my friends where I was on those Sunday mornings because I was embarrassed I was different from them. Their ancestors had immigrated from Western Europe so long ago that their cultural bonds had all blended into one big mass of confused nationalities. I, on the other hand, was Russian, and the only one out of my friends whose grandparents spoke poor English and celebrated different holidays. It wasn\u27t until my grandfather passed away that I first became aware of the importance of my heritage. The belongings he left me were all from Russia, and all told a story. For the first time in my life I was ready to listen. Writing this piece for GWRIT 102D was a way to prove that I was no longer ashamed of my nationality. Retelling the tale of my grandmother\u27s life came easily because it is now a part of me. While writing this essay I incorporated my grandmother\u27s experiences into the historical events that were taking place simultaneously during the Russian Revolution. Hearing someone who lived through a historical event share their experiences gives a different perspective then is traditionally found in textbooks. The goal of this piece was to convey the emotions of my grandmother in a story that illustrates Russian history from her perspective. My Russian heritage has taught me a lot, not only about the people my relatives really are, but also about the history of the country that they used to call home

Productive Longevity and Yield Quality of Galega-Grass Swards

Fodder galega (Galega orientalis Lam.) is an early maturing, very productive perennial forage legume that fixes atmospheric nitrogen. Unlike other legumes, pure stands of fodder galega provide stable yields of green feed and seeds and do not thin out between the years. The symbiotic potential of fodder galega to grow in mixtures with grasses can be exploited to produce ecologically safe forage and animal products

Nanosecond pulse discharges for plasma assisted combustion and low-temperature plasma chemistry

Recent experimental studies of repetitive nanosecond pulse discharges demonstrate their significant potential for plasma assisted combustion, high-speed flow control, and low-temperature plasma chemistry. The main advantage of using these discharges for ignition is efficient generation of electronically excited and radical species. In the experiments, time-resolved temperature, N2 vibrational level populations, absolute O, H, and OH number densities, and ignition delay time are measured in premixed hydrocarbon–air, hydrogen–air, and hydrogen–oxygen–argon flows excited by repetitive nanosecond pulse discharges in plane-to-plane and point-to-point geometries. Time-resolved temperature and OH number density in lean H2–air, CH4–air, C2H4–air, and C3H8–air mixtures are measured by picosecond, broadband Coherent Antistokes Raman Spectroscopy (CARS) and by OH Laser-Induced Fluorescence (LIF). Time-resolved, spatially resolved temperature and absolute number densities of OH and H in Ar–O2–H2 mixtures are measured by UV Rayleigh scattering, LIF, and Two-Photon Absorption LIF (TALIF), respectively. The results demonstrate that ignition occurs due to efficient generation of radicals in the discharge and provide insight into the kinetic mechanism of low-temperature plasma assisted ignition. Time-resolved electron density, electron temperature, and electric filed in transient nanosecond pulse discharges are measured by Thomson scattering and picosecond CARS/4-wave mixing. Comparison with kinetic modeling calculations shows the need for development of a predictive low-temperature plasma/fuel chemistry model applicable to fuels C3 and higher. Kinetics of nanosecond pulse nonequilibrium electric discharges in liquids and at liquid–vapor interfaces is of great interest for applications such as reactive nitrogen/oxygen species generation, plasma activation of water, removal of volatile organic compounds from aqueous solutions, and plasma chemical reforming of liquid hydrocarbons and oxygenates. One of the main difficulties in studies of liquid/vapor phase plasma chemistry is sustaining the plasma at controlled, reproducible conditions which would lend themselves to in situ optical diagnostics. Dynamics of discharge development and kinetics of energy coupling in liquid–vapor interface plasmas remains poorly understood. Plasmachemical reactions near the vapor–surface interface may occur at high peak electric fields and low temperatures, due to rapid evaporative cooling of the liquid. Surface ionization wave discharges generated by high-voltage nanosecond pulses are studied over liquid–vapor surfaces (water and alcohols). Over a wide range of conditions, surface plasma “sheet” remains diffuse. No perturbation of the liquid surface by the discharge was detected. Products of plasma chemical reaction accumulated in the ionization wave discharge over liquid butanol/saturated butanol vapor interface are detected ex situ, using FTIR absorption spectroscopy. Reaction products identified include CO, alkanes, alkynes, aldehydes, and lighter alcohols. In situ laser diagnostics are used to measure radical species concentrations (OH LIF and H TALIF). Absolute, two-dimensional distributions of [OH] and [H] have been measured in a repetitively pulsed nanosecond discharge sustained near liquid water/saturated water vapor interface. The results suggest significant potential of this approach for near-surface plasmachemical reforming of evaporating liquid reactants

Equity investment in China: past experience and prospects

In this paper the focus is on foreign direct investment (“FDI”) where an investor has a degree of control over a business which is more significant than that of a portfolio investor. In other words the investor is able to impact upon the management and operations of the enterprise. Its quantum and function are important to gauge especially in developing countries because: · it is generally longer term and less mercurial than portfolio investment, bank lending and traditional bond based lending; · it adds to a country’s source of capital and can facilitate skill transfers and technologies; and · if laws allow it permits a more efficient international allocation of capital

The effect of many sources on the genuine multiparticle correlations

We report on a study aimed to explore the dependence of the genuine multiparticle correlations on the number of sources when the influence of other possible factors during multihadron production are avoided. The analysis utilised the normalised cumulants calculated in three-dimensional phase space of the reaction ee -> Z -> hadrons using a large Monte Carlo sample. The multi-sources events were simulated by overlaying a few independent single ee annihilation events. It was found that as the number of sources increases, the cumulants do not change significantly their structure, but those of an order higher than two decrease fast in their magnitude. This reduction and its amount can be understood in terms of combinatorial considerations of source mixing which dilutes the correlations. The diminishing of the genuine correlations is consistent with recent cumulant measurements in hadron and nucleus induced reactions and should also be relevant to other dynamical correlations like the Bose-Einstein one, in ee -> WW -> hadrons and in nucleus-nucleus reactions

On the intrinsic charm and the recombination mechanisms in charm hadron production

We study $\Lambda_c^\pm$ production in $pN$ and $\pi^-N$ interactions. Recent experimental data from the SELEX and E791 Collaborations at FNAL provide important information on the production mechanism of charm hadrons. In particular, the production of the $\Lambda_c$ baryon provides a good test of the intrinsic charm and the recombination mechanisms, which have been proposed to explain the so called leading particle effects.Comment: 11 pages, two figures (postscript), late