Running coupling constant and masses in QCD, the meson spectrum

In line with some previous works, we study in this paper the meson spectrum in the framework of a second order quark-antiquark Bethe-Salpeter formalism which includes confinement. An analytic one loop running coupling constant alpha_s(Q), as proposed by Shirkov and Sovlovtsov, is used in the calculations. As for the quark masses, the case of a purely phenomenological running mass for the light quarks in terms of the c. m. momentum is further investigated. Alternatively a more fundamental expression m_P(Q) is introduced for light and strange quarks, combining renormalization group and analyticity requirements with an approximate solution of the Dyson-Schwinger equation. The use of such running coupling constant and masses turns out to be essential for a correct reproduction of the the light pseudoscalar mesons.Comment: 10 pages, 2 figures, conference: Quark Confinement and the Hadron Spectrum VI, Villasimius, Cagliari, Ital

B_{c} meson and the light-heavy quarkonium spectrum

We compute the c \bar{b} spectrum from a first principle Salpeter equation obtained in a preceding paper. For comparison we report also the heavy-light quarkonium spectrum and the hyperfine separations previously presented only in a graphical form. Notice that all results are parameter free.Comment: 7 pages. Minor changes; references added. Accepted for publication on Phys. Rev.

Infrared behavior of the running coupling constant and quarkonium spectrum

We study the effect of the infrared behavior of the running coupling constant on the quark-antiquark spectrum.Comment: 3 pages. 1 figure, talk given at the 5th International Conference "Quark Confinement and the Hadron Spectrum", September 10-14, 2002. Gargnano sul Garda (BS) Ital

Indirect Effects of Eco-labelling of agricultural products on Natural Resources

The implementation of eco-labelling schemes for agricultural and food products may represent an opportunity to enhance production technologies compatible with the sustainable economic approach. The paper presents an attempt to design a comprehensive methodological framework in which the consumer behaviour change is the driving force for redirecting the market, the production, and the international trade. This approach focuses on the specification of the most relevant variables necessary to implement a simplified, but comprehensive analysis, from which it is possible to proceeding to a broad estimate of the changes in terms of consumption patterns, revenue distribution, import and export, and natural resources consumption. On a theoretical basis, the framework highlights that the most relevant conservation effect on natural resources, occurs when the eco-labelling schemes are enforced by two countries, under a market regime of free trade. On the contrary, if only one country adopts the schemes, then the effect is negligible.environmental labelling, natural resources conservation, international trade, Food Consumption/Nutrition/Food Safety, Resource /Energy Economics and Policy,