Jet Correlations of Identified Particles in PHENIX

Azimuthal two particle correlations at intermediate $p_{T}$ with one of the particles identified have been measured at PHENIX. Trigger ($2.5 < p_{T} < 4.0 GeV/c$) baryons and mesons show little significant difference in the number of associated particles ($1.7 < p_{T} < 2.5 GeV/c$) independent of centrality. For inclusive hadron triggers with $2.5 < p_{T} < 4.0 GeV/c$, associated fragmentation particles with $1.0 < p_{T} < 2.5 GeV/c$ show a higher baryon to meson ratio on the away side.Comment: talk given at Quark Matter 2004, 4 pages 4 figur

Dihadron Correlation in Jets Produced in Heavy-Ion Collisions

The difference between the structures of jets produced in heavy-ion and hadronic collisions can best be exhibited in the correlations between particles within those jets. We study the dihadron correlations in jets in the framework of parton recombination. Two types of triggers, $\pi^+$ and proton, are considered. It is shown that the recombination of thermal and shower partons makes the most important contribution to the spectra of the associated particles at intermediate $p_T$. In $pp$ collisions the only significant contribution arises from shower-shower recombination, which is negligible in heavy-ion collisions. Moments of the associated-particle distributions are calculated to provide simple summary of the jet structures for easy comparison with experiments.Comment: 24 pages in Latex + 5 figure

Efficiency and Productivity Growth Comparisons of European and U.S. Air Carriers : A First Look at the Data

air transport ; productivity

Hadronization of Dense Partonic Matter

The parton recombination model has turned out to be a valuable tool to describe hadronization in high energy heavy ion collisions. I review the model and revisit recent progress in our understanding of hadron correlations. I also discuss higher Fock states in the hadrons, possible violations of the elliptic flow scaling and recombination effects in more dilute systems.Comment: 8 pages, 4 figures; plenary talk delivered at SQM 2006, to appear in J. Phys.

PHENIX Highlights

Recent highlights of measurements by the PHENIX experiment at RHIC are presented.Comment: 8 pages, 9 figures. Talk at Quark Matter 200

An analysis of strategic behavior in eBAY auctions

A relatively new type of panel data analysis is becoming more and more topical in the applied econometrics literature as auction mechanisms are being explored in more depth. The typical data utilized in such studies involves repeated measures of auction outcomes, where the variable of interest involves order statistics from the sample of bids from many bids on completed auctions for a particular commodity. This article presents structural estimates of bidding behavior in eBay computer monitor auctions. We exploit characteristics of such repeated measures to analyze the efficiency of private value auctions for a relatively homogeneous good, computer monitors sold on eBay. We discuss how outcomes of the auction mechanism can be analyzed and their equilibrium outcomes assessed and evaluate the consumer surplus that is generated from such auctions. Particular attention is given to the collection of the eBay data from data recovery protocols that monitor in real time and in relative detail, characteristics of a particular auction with heterogeneity controls for different types of monitors and for different reputation effects of the auctioneer. Among other findings, our results point to a rejection of the use of Jump Bidding (Avery, 1998) or "Snipe or War" bidding (Roth and Ockenfels, 2002). We also find that longer auctions only have a small effect on price and experienced auctioneers respond to this incentive. © 2009 World Scientific Publishing Company

The ASAC Air Carrier Investment Model (Second Generation)

To meet its objective of assisting the U.S. aviation industry with the technological challenges of the future, NASA must identify research areas that have the greatest potential for improving the operation of the air transportation system. To accomplish this, NASA is building an Aviation System Analysis Capability (ASAC). The ASAC differs from previous NASA modeling efforts in that the economic behavior of buyers and sellers in the air transportation and aviation industries is central to its conception. To link the economics of flight with the technology of flight, ASAC requires a parametrically based mode with extensions that link airline operations and investments in aircraft with aircraft characteristics. This model also must provide a mechanism for incorporating air travel demand and profitability factors into the airlines' investment decisions. Finally, the model must be flexible and capable of being incorporated into a wide-ranging suite of economic and technical models that are envisioned for ASAC. We describe a second-generation Air Carrier Investment Model that meets these requirements. The enhanced model incorporates econometric results from the supply and demand curves faced by U.S.-scheduled passenger air carriers. It uses detailed information about their fleets in 1995 to make predictions about future aircraft purchases. It enables analysts with the ability to project revenue passenger-miles flown, airline industry employment, airline operating profit margins, numbers and types of aircraft in the fleet, and changes in aircraft manufacturing employment under various user-defined scenarios