Nucleon and Delta resonances in K Sigma(1385) photoproduction from nucleons

The reaction mechanisms for $K\Sigma(1385)$ photoproduction from the reaction $\gamma p \to K^+\Sigma^{0}(1385)$ in the resonance energy region are investigated in a hadronic model. Both contributions from $N$ and $\Delta$ resonances of masses around 2 GeV as given in the Review of Particle Data Group and by the quark model predictions are included. The Lagrangians for describing the decays of these resonances into $K\Sigma(1385)$ are constructed with the coupling constants determined from the decay amplitudes predicted by a quark model. Comparing the resulting total cross section for the reaction $\gamma p \to K^+\Sigma^{0}(1385)$ with the preliminary data from the Thomas Jefferson National Accelerator Facility, we find that the most important contributions are from the two-star rated resonances $\Delta(2000) F_{35}$, $\Delta(1940) D_{33}$, and $N(2080) D_{13}$, as well as the missing resonance $N\frac32^-(2095)$ predicted in the quark model. Predictions on the differential cross section and photon asymmetry in this reaction are also given.Comment: 13 pages, 6 figures, REVTeX, to appear in Phys. Rev.

Interorganizational Information Exchange and Efficiency: Organizational Performance in Emergency Environments

Achieving efficiency in coordinated action in rapidly changing environments has challenged both researchers and practitioners. Emergency events require both rapid response and effective coordination among participating organizations. We created a simulated operations environment using agent-based modeling to test the efficiency of six different organizational designs that varied the exercise of authority, degree of uncertainty, and access to information. Efficiency is measured in terms of response time, identifying time as the most valuable resource in emergency response. Our findings show that, contrary to dominant organizational patterns of hierarchical authority that limit communication among members via strict reporting rules, any communication among members increases the efficiency of organizations operating in uncertain environments. We further found that a smaller component of highly interconnected, self adapting agents emerges over time to support the organization\'s adaptation in changing conditions. In uncertain environments, heterogeneous agents prove more efficient in sharing information that guides coordination than homogeneous agents.Agent-Based Simulation, Emergency Management, Network Evolution, Performance

Neutral scalar Higgs bosons in the USSM at the LHC

We study the possibility of discovering neutral scalar Higgs bosons in the $U(1)'$-extended supersymmetric standard model (USSM) at the CERN Large Hadron Collider (LHC), by examining their productions via the exotic quark loop in the gluon fusion process at leading order. It is possible in some parameter region that the neutral scalar Higgs bosons may have stronger couplings with the exotic quarks than with top quark. In this case, the exotic quarks may contribute more significantly than top quark in productions of the neutral scalar Higgs bosons in the gluon fusion process. We find that there is indeed some parameter region in the USSM that supports our speculations.Comment: 18 pages; changed content; JPhys

Diversity, Stability, Recursivity, and Rule Generation in Biological System: Intra-inter Dynamics Approach

Basic problems for the construction of a scenario for the Life are discussed. To study the problems in terms of dynamical systems theory, a scheme of intra-inter dynamics is presented. It consists of internal dynamics of a unit, interaction among the units, and the dynamics to change the dynamics itself, for example by replication (and death) of units according to their internal states. Applying the dynamics to cell differentiation, isologous diversification theory is proposed. According to it, orbital instability leads to diversified cell behaviors first. At the next stage, several cell types are formed, first triggered by clustering of oscillations, and then as attracting states of internal dynamics stabilized by the cell-to-cell interaction. At the third stage, the differentiation is determined as a recursive state by cell division. At the last stage, hierarchical differentiation proceeds, with the emergence of stochastic rule for the differentiation to sub-groups, where regulation of the probability for the differentiation provides the diversity and stability of cell society. Relevance of the theory to cell biology is discussed.Comment: 19 pages, Int.J. Mod. Phes. B (in press

Simulations of deposition growth models in various dimensions. Are overhangs important?

We present simulation results of deposition growth of surfaces in 2, 3 and 4 dimensions for ballistic deposition where overhangs are present, and for restricted solid on solid deposition where there are no overhangs. The values of the scaling exponents for the two models are found to be different, suggesting that they belong to different universality classes.Comment: figures available from author