Do Macroeconomic Variables Affect the Agricultural Trade Sector? An Elasticities Analysis

International Relations/Trade,

Chargino Production and Decay in Photon-Photon-Collisions

We study the production and leptonic decay of charginos in collisions of polarized photon beams including the complete spin correlations. The photons can be generated by Compton backscattering of polarized laser pulses off a polarized electron beam. Since the production process is determined alone by the electromagnetic coupling of the charginos this process allows to study their decay dynamics. The cross section and the forward-backward asymmetry of the decay lepton are very sensitive to the gaugino mass parameter $M_1$ and to the sneutrino mass without any ambiguities.Comment: 9 pages, 6 figures, LaTeX, Talk presented at the International Workshop on High Energy Photon Collider

Labeling Policies in Food Markets: Private Incentives, Public Intervention, and Welfare Effects

This study considers the welfare impact of labeling policies of agricultural commodities with specific characteristics. Using a model of vertical differentiation, the effects on equilibrium and welfare levels are calculated. The introduction of the regulation and the emergence of two differentiated competitive markets leaves consumers and high-quality producers better off, while low-quality producers are worse off. With high costs and low quality differences, the total welfare impact of the regulation can be negative. Findings show that when high-quality producers can exercise market power, the regulation could be more easily accepted by producers, but it would have a negative effect on consumers.asymmetric information, food markets, labeling, market power, vertical differentiation, welfare effects, Agricultural and Food Policy,

Impact of e^+ and e^- Beam Polarization on Chargino and Neutralino Production at a Linear Collider

We study the production processes e^+ e^- -> chi^+_i chi^-_j, i,j=1,2, and e^+ e^- -> chi^0_m chi^0_n, m,n=1,...,4, working out the advantages of polarizing both beams. For e^+ e^- -> chi^+_1 chi^-_1 with chi^-_1 -> chi^0_1 e^- nu and e^+ e^- -> chi^0_1 chi^0_2 with chi^0_2 -> chi^0_1 e^+ e^- we perform a detailed analysis, including the complete spin correlations between production and decay. We analyze the forward--backward asymmetry of the decay electron for various beam polarizations. We also study polarization asymmetries in e^+ e^- -> chi^0_1 chi^0_2. These asymmetries strongly constrain the gaugino parameter M_1 and the masses m_{\tilde{e}_L}, m_{\tilde{e}_R}, m_{\tilde{nu}} also if m_{\tilde{e}_{L,R}}, m_{\tilde{nu}} > sqrt{s}/2. We give numerical predictions for three scenarios for a linear collider with sqrt{s}=500-1000 GeV.Comment: 26 pages, 26 postscript figures, latex using epsfi

Exploiting Spin Correlations in Neutralino Production and Decay with Polarized e^- and e^+ Beams

We study the production process e^+ e^- -> chi^0_1 chi^0_2 and the subsequent decay chi^0_2 -> chi^0_1 l^+ l^- with polarized e^+ and e^- beams, including the spin correlations between production and decay. We work out the advantages of polarizing both beams. We study in detail the angular distribution and the forward--backward asymmetry of the decay lepton as well as the opening angle distribution between the decay leptons. We investigate the dependence on the masses of tilde{e}_L and tilde{e}_R and on the mixing character of the neutralinos. In particular we study the dependence on the gaugino mass parameter M_1.Comment: 17 pages, 14 postscript figures, latex using epsfi

DOES INDUSTRIAL CONCENTRATION RAISE PRODUCTIVITY IN FOOD INDUSTRIES?

This manuscript investigates the productivity-industrial concentration relationship in U.S. food industries. We identify a critical level of industrial concentration beyond which its relationship with productivity growth becomes negative. The welfare effects of an increase in concentration - productivity growth and deadweight loss- are computed. Welfare loss from increasing concentration is substantially offset by gains from productivity growth.Industrial Organization, Productivity Analysis,

Beam Polarization and Spin Correlation Effects in Chargino Production and Decay

We study chargino production e^+ e^- -> chi^+_1 chi^-_1 and the subsequent leptonic decay chi^-_1\to chi^0_1 e^- nu_e including the complete spin correlations between production and decay. We work out the advantages of polarizing the e^+ and e^- beams. We study in detail the polarized cross sections, the angular distribution and the forward--backward asymmetry of the decay electron. They can be used to determine the sneutrino mass m_{\tilde{\nu}_e}.Comment: 14 pages, 17 postscript figures, latex using epsfi

Identifying the NMSSM by the interplay of LHC and ILC

The interplay between the LHC and the $e^+ e^-$ International Linear Collider (ILC) with $\sqrt{s}=500$ GeV might be crucial for the discrimination between the minimal and next-to-minimal supersymmetric standard model. We present an NMSSM scenario, where the light neutralinos have a significant singlino component, that cannot be distinguished from the MSSM by cross sections and mass measurements. Mass and mixing state predictions for the heavier neutralinos from the ILC analysis at different energy stages and comparison with observation at the LHC, lead to clear identification of the particle character and identify the underlying supersymmetric model.Comment: 8 pages, 2 eps figures, revtex4 style Contribution to the `2005 International Linear Collider Workshop - Stanford, U.S.A.