Squeezed K^+ K^- correlations in high energy heavy ion collisions

The hot and dense medium formed in high energy heavy ion collisions may modify some hadronic properties. In particular, if hadron masses are shifted in-medium, it was demonstrated that this could lead to back-to-back squeezed correlations (BBC) of particle-antiparticle pairs. Although well-established theoretically, the squeezed correlations have not yet been discovered experimentally. A method has been suggested for the empirical search of this effect, which was previously illustrated for phi-phi pairs. We apply here the formalism and the suggested method to the case of K^+ K^- pairs, since they may be easier to identify experimentally. The time distribution of the emission process plays a crucial role in the survival of the BBC's. We analyze the cases where the emission is supposed to occur suddenly or via a Lorentzian distribution, and compare with the case of a Levy distribution in time. Effects of squeezing on the correlation function of identical particles are also analyzed.Comment: 9 pages and 6 figures (figures 2 to 6 contain 4 plots each). Paragraph added to text, figures 2 to 6 revised for improving visualizatio

Mitigating Damages From Coastal Wetlands Development: Policy, Economics and Financing

This paper looks at the problem of modeling the welfare consequences of the effects of environmental changes on the bioeconomic equilibrium of fisheries. The equilibrium catch equation is suggested as the most appropriate mechanism for modelling these effects. Several different models are presented, based on the availability of data. It is shown that a model in which the equilibrium catch function is estimated directly as a function of environmental quality will be superior to a model which takes the stock effects from an independent ecosystem model. Models are also suggested for those cases in which only proxies for stock levels are available, and for those cases in which no stock data are available.Environmental Economics and Policy, Land Economics/Use, Public Economics, Research Methods/ Statistical Methods, Resource /Energy Economics and Policy, Risk and Uncertainty,

Testing the Resolving Power of 2-D K^+ K^+ Interferometry

Adopting a procedure previously proposed to quantitatively study two-dimensional pion interferometry, an equivalent 2-D chi^2 analysis was performed to test the resolving power of that method when applied to less favorable conditions, i.e., if no significant contribution from long lived resonances is expected, as in kaon interferometry. For that purpose, use is made of the preliminary E859 K^+ K^+ interferometry data from Si+Au collisions at 14.6 AGeV/c. As expected, less sensitivity is achieved in the present case, although it still is possible to distinguish two distinct decoupling geometries. The present analysis seems to favor scenarios with no resonance formation at the AGS energy range, if the preliminary K^+ K^+ data are confirmed. The possible compatibility of data with zero decoupling proper time interval, conjectured by the 3-D experimental analysis, is also investigated and is ruled out when considering more realistic dynamical models with expanding sources. These results, however, clearly evidence the important influence of the time emission interval on the source effective transverse dimensions. Furthermore, they strongly emphasize that the static Gaussian parameterization, commonly used to fit data, cannot be trusted under more realistic conditions, leading to distorted or even wrong interpretation of the source parameters!Comment: 11 pages, RevTeX, 4 Postscript figures include

FQPA IMPLEMENTATION TO REDUCE PESTICIDE RESIDUE RISKS: PART I: AGRICULTURAL PRODUCER CONCERNS

The Food Quality Protection Act of 1996 (FQPA) transforms the regulation of pesticide residues on food in the United States. Three changes are prominent. First, under the FQPA, the U.S. Environmental Protection Agency (EPA) is authorized to develop uniform pesticide residue tolerances for both fresh and processed foods. These tolerances must be based on a conservative standard appropriate for infants and children, rather than the adult-based tolerances that prevailed previously for fresh-market produce. Second, under the FQPA, pesticide registration will be based upon aggregate risk to the most susceptible consumers from all pesticides sharing a common biochemical mode of action in humans. Third, the FQPA expands the scope of health effects included in risk assessment decisions to include potential endocrine and reproductive effects of pesticidal chemicals. As the EPA has moved to develop implementation guidelines for the FQPA, agricultural producers and input suppliers have become concerned about its impact on them. Even if the FQPA's implementation results only in a restriction of the pesticides used on some crops, producers still have four major concerns: (1) the potential loss of farm profitability, especially for farms specializing in fruit and vegetable production; (2) unfair competition if foreign competitors can use pesticides forbidden to domestic producers; (3) the impact of the FQPA on consumer purchases, (i.e., if reduced pesticide use results in more blemishes or lower quality product, will consumers refuse to purchase the product?); and (4) excessive reliance on a few remaining pest control weapons, possibly resulting in accelerated pest resistance. Because these uncertainties potentially impact producers' livelihoods, many argue for a go-slow, long transition for any major changes in the way they farm or the pest control products they use. Competing with these agricultural concerns, however, are a parallel set of concerns, expressed by consumer and environmental groups, that the FQPA's promise to protect infants and children from pesticide risks will be sabotaged by lax or ineffective implementation. There are many uncertainties with respect to the impacts related to alternative FQPA implementation strategies. Research to resolve these concerns is fragmentary and frequently inconclusive. The common element that emerges from this review of producer concerns is: Impacts on producers will depend on how the FQPA is implemented.Crop Production/Industries, Food Consumption/Nutrition/Food Safety,

FQPA IMPLEMENTATION TO REDUCE PESTICIDE RESIDUE RISKS: PART II: IMPLEMENTATION ALTERNATIVES AND STRATEGIES

Implementation of the Food Quality Protection Act (FQPA) is fraught with difficulty due to the divergent perspectives and demands of stakeholders in the process. In "Part I: Agricultural Producer Concerns," the authors reviewed the concerns of food producers about potential FQPA threats to farm profitability, international competitiveness, consumer perceptions, and the development of pest resistance to remaining pesticides. Fortunately, lessons from past environmental policy and economic theory offer useful principles for how to implement the FQPA. This paper, "Part II: Implementation Alternatives and Strategies" addresses ways to accommodate producer concerns while meeting the policy mandate of reducing risk from pesticide exposure, especially for infants and children. In so doing, the authors are neither advocating nor criticizing this FQPA policy mandate; rather, they are providing policy analysis of alternative implementation strategies.Crop Production/Industries, Food Consumption/Nutrition/Food Safety,

THE ENVIRONMENTAL QUALITY INCENTIVES PROGRAM: LOCALLY MANAGING NATURAL RESOURCES

Environmental Economics and Policy, Resource /Energy Economics and Policy,

A CONTINUATION OF ENVIRONMENTAL CONSERVATION POLICY: THE CONSERVATION RESERVE PROGRAM

Environmental Economics and Policy, Land Economics/Use,