Properties of scalar--isoscalar mesons from multichannel interaction analysis below 1800 MeV

Scalar-isoscalar mesons are studied using an unitary model in three channels: pi-pi, K-anti K and an effective 2pi-2pi. All the solutions, fitted to the pi-pi and K-anti K data, exhibit a wide f0(500), a narrow f0(980) and two relatively narrow resonances, lying on different sheets between 1300 MeV and 1500 MeV. These latter states are similar to the f0(1370) and f0(1500) seen in experiments at CERN. Branching ratios are compared with available data. We have started investigations of some crossing symmetry and chiral constraints imposed near the pi-pi threshold on the scalar-isoscalar, scalar-isotensor and P-wave pi-pi amplitudes.Comment: Talk given at XVth Particles and Nuclei Int. Conf. (PANIC99), Uppsala, Sweden, June 10-16, 1999; 4 pages, 3 figures, file espcrc1.sty include

THE GENUS TETRACERA (DILLENIACEAE) IN THE EASTERN OLD WORLD

1. An account of the genus Tetracera L. in the eastern Old World (Asia, Malaysia,Australia, New Caledonia) is given. The Malaysian species have already been in cluded in the revision of the Dilleniaceae in "Flora malesiana" (I 4: 141-149. 1951). 2. The main part of the present paper consists of a key to the species, followed by a systematic treatment of the 15 species admitted for the region. 3. Latin diagnoses are given for three new subspecies under Tetracera asiatiea (Lour.) Hoogl. and two new varieties under Tetracera nordtiana F. Muell. 4. A number of species are reduced either to the rank of variety or to synonymy. 5. Distribution-maps are provided for the species of which a relatively large number of specimens has been studied

Quasi-Monte Carlo, Discrepancies and Error Estimates

We discuss the problem of defining an estimate for the error in quasi-Monte Carlo integration. The key issue is the definition of an ensemble of quasi-random point sets that, on the one hand, includes a sufficiency of equivalent point sets, and on the other hand uses information on the degree of uniformity of the point set actually used, in the form of a discrepancy or diaphony. A few examples of such discrepancies are given. We derive the distribution of our error estimate in the limit of large number of points. In many cases, Gaussian central limits are obtained. We also present numerical results for the quadratic star-discrepancy for a number of quasi-random sequences

Amplitudes Fitted to Experimental Data and to Roy's Equations

The scalar-isoscalar, scalar-isotensor and vector-isovector pi-pi amplitudes are fitted simultaneously to experimental data and to Roy's equations. The resulting amplitudes are compared with those fitted only to experimental data. No additional constraints for the pi-pi threshold behaviour of the amplitudes are imposed. Threshold parameters are calculated for the amplitudes in the three waves. Spectrum of scalar mesons below 1.8 GeV is found from the analysis of the analytical structure of the fitted amplitudes.Comment: 3 pages, 1 figure. Talk given at MESON 2004: 8th International Workshop on Meson Production, Properties and Interactions, Cracow, Poland, 4-8 Jun 2004. Submitted to Int.J.Mod.Phys.

Monte Carlo Renormalization of the 3-D Ising model: Analyticity and Convergence

We review the assumptions on which the Monte Carlo renormalization technique is based, in particular the analyticity of the block spin transformations. On this basis, we select an optimized Kadanoff blocking rule in combination with the simulation of a d=3 Ising model with reduced corrections to scaling. This is achieved by including interactions with second and third neighbors. As a consequence of the improved analyticity properties, this Monte Carlo renormalization method yields a fast convergence and a high accuracy. The results for the critical exponents are y_H=2.481(1) and y_T=1.585(3).Comment: RevTeX, 4 PostScript file

The Role of Leaders in Managing Envy and its Consequences for Competition in Organizations

Leaders in organizations face numerous challenges. Among these is helping employees cope with the fact that, over time, some in the organization will succeed and some will fail, leading to potentially disruptive emotions. One of the leader’s roles is to understand and manage these emotions to ensure they do not result in negative interpersonal or organizational outcomes. Further, through their words and deeds, leaders can foster a culture in which more positive emotional reactions to others’ fortunes are more likely to occur, ultimately benefitting the individuals involved and the organization as a whole. Although there are numerous possible reactions to the positive and negative fortunes of others, this chapter will focus mainly on benign or malicious envy in response to another’s success and the implications of these two types of envy for destructive or constructive responses to a successful other. We will give particular attention to one example of the consequences of malicious envy, schadenfreude, pleasure when the more fortunate other suffers a setback. We will examine why malicious envy creates the conditions for schadenfreude and suggest how leaders can prevent it from harming their organizations. We will suggest that leaders, through their influence on employee’s perceptions of justice, feelings of control, and organizational culture, can shape their envy so that it is benign rather than malicious in nature -- thus minimizing negative responses and promoting positive responses instead

Multidimensional sampling for simulation and integration: measures, discrepancies, and quasi-random numbers

This is basically a review of the field of Quasi-Monte Carlo intended for computational physicists and other potential users of quasi-random numbers. As such, much of the material is not new, but is presented here in a style hopefully more accessible to physicists than the specialized mathematical literature. There are also some new results: On the practical side we give important empirical properties of large quasi-random point sets, especially the exact quadratic discrepancies; on the theoretical side, there is the exact distribution of quadratic discrepancy for random point sets.Comment: 51 pages. Full paper, including all figures also available at: ftp://ftp.nikhef.nl/pub/preprints/96-017.ps.gz Accepted for publication in Comp.Phys.Comm. Fixed some typos, corrected formula 108,figure 11 and table