Reheating after Supercooling in the Chiral Phase Transition

The chirally symmetric quark-gluon plasma produced in energetic heavy-ion collisions is predicted to supercool at the late stages of its evolution. The thermal energy is then transformed into the potential energy associated with an energetically unfavorable field configuration. Since the system is in an unstable state it eventually rolls down to the true minimum of the effective chiral potential. When this motion is described in terms of the sigma-model, we find that the energy of the coherent $\sigma-$field is very efficiently converted into pionic excitations due to anharmonic oscillations around this minimum. The system is expected to partially thermalize before its disintegration.Comment: Final version accepted for publication, 8 pages, REVTe

Do price-tags influence consumers' willingness to pay ? On external validity of using auctions for measuring value

The paper considers the external validity of the growing set of literature that uses laboratory auctions to reveal consumers' willingness to pay for consumer goods, when the concerned goods are sold in retailing shops through posted prices procedures. Here, the quality of the parallel between the field and the lab crucially depends on whether being informed of the actual field price influences a consumer's willingness to pay for a good or not. We show that the elasticity of the WTP revision, according to the field price estimation error, is significant, positive and can be roughly approximate to one quarter of the error. We then discuss the normative implications of these results for future experiments aimed at eliciting private valuations through auctions.EXPERIMENTAL ECONOMICS;WILLINGNESS TO PAY;AUCTION;POSTED PRICE;VALUE ELICITATION;CONSUMER BEHAVIOR

What is the temperature in heavy ion collisions?

We consider the Tsallis distribution as the source of the apparent slope of one-particle spectra in heavy-ion collisions and investigate the equation of state of this special quark matter in the framework of non-extensive thermodynamics.Comment: Talk given by T.S.Biro at RHIC School 2003, Dec.8-11, 2003, Budapest, Hungar

Anomalous Transport Processes in Anisotropically Expanding Quark-Gluon Plasmas

We derive an expression for the anomalous viscosity in an anisotropically expanding quark-gluon-plasma, which arises from interactions of thermal partons with dynamically generated color fields. The anomalous viscosity dominates over the collisional viscosity for large velocity gradients or weak coupling. This effect may provide an explanation for the apparent ``nearly perfect'' liquidity of the matter produced in nuclear collisions at RHIC without the assumption that it is a strongly coupled state.Comment: 31 pages, 1 figure, some typos in published version are correcte

To what extent would the poorest consumers nutritionally and socially benefit from a global food tax and subsidy reform ? A framed field experiment based on daily food intake

In this paper we propose a new method in experimental economics, designed to evaluate the effectiveness of public policy incentives aimed at altering consumer behaviors. We apply this method to wide-ranging policies on food prices, which use subsidies to increase the consumption of healthy products and taxes to reduce that of unhealthy ones. Our protocol allows for observation of an individual’s daily food consumption before and after the policy. We examine two separate policies: the one subsidizes fruit and vegetables, while the other one combines taxes and subsidies. We measure their nutritional and economic impacts on the choices of low-income French consumers, compared to a reference group. Both policies have a positive effect on the nutritional quality of food choices of the two groups but initial gaps widen, especially with the subsidies. In the low-income group this can be explained by an initially unfavorable pattern and by weaker price elasticities. The redistributive effects are therefore doubly regressive. Moreover, the individual price elasticities, that the experimental approach enables us to measure, show widely diverse behaviors. They are counter-effective for close to 40% of our sample of poor women.OBESITY;PUBLIC POLICY;SOCIAL INEQUALITIES;POVERTY;INCOME REDISTRIBUTION;REGRESSIVE TAX;INDIVIDUALIZED PRICE INDEX;NUTRITIONAL TAX SYSTEM;FOOD TAX