Scaling functions for O(4) in three dimensions

Monte Carlo simulation using a cluster algorithm is used to compute the scaling part of the free energy for a three dimensional O(4) spin model. The results are relevant for analysis of lattice studies of high temperature QCD.Comment: 12 pages, 6 figures, uses epsf.st

Quenched charmonium spectrum

We study charmonium using the standard relativistic formalism in the quenched approximation, on a set of lattices with isotropic lattice spacings ranging from 0.1 to 0.04 fm. We concentrate on the calculation of the hyperfine splitting between eta_c and J/psi, aiming for a controlled continuum extrapolation of this quantity. The splitting extracted from the non-perturbatively improved clover Dirac operator shows very little dependence on the lattice spacing for $a \leq 0.1$ fm. The dependence is much stronger for Wilson and tree-level improved clover operators, but they still yield consistent extrapolations if sufficiently fine lattices, $a \leq 0.07$ fm ($a M(\eta_c) \leq 1$), are used. Our result for the hyperfine splitting is 77(2)(6) MeV (where Sommer's parameter, r_0, is used to fix the scale). This value remains about 30% below experiment. Dynamical fermions and OZI-forbidden diagrams both contribute to the remainder. Results for the eta_c and J/psi wave functions are also presented.Comment: 22 pages, 7 figure

Heavy quarkonium: progress, puzzles, and opportunities

A golden age for heavy quarkonium physics dawned a decade ago, initiated by the confluence of exciting advances in quantum chromodynamics (QCD) and an explosion of related experimental activity. The early years of this period were chronicled in the Quarkonium Working Group (QWG) CERN Yellow Report (YR) in 2004, which presented a comprehensive review of the status of the field at that time and provided specific recommendations for further progress. However, the broad spectrum of subsequent breakthroughs, surprises, and continuing puzzles could only be partially anticipated. Since the release of the YR, the BESII program concluded only to give birth to BESIII; the $B$-factories and CLEO-c flourished; quarkonium production and polarization measurements at HERA and the Tevatron matured; and heavy-ion collisions at RHIC have opened a window on the deconfinement regime. All these experiments leave legacies of quality, precision, and unsolved mysteries for quarkonium physics, and therefore beg for continuing investigations. The plethora of newly-found quarkonium-like states unleashed a flood of theoretical investigations into new forms of matter such as quark-gluon hybrids, mesonic molecules, and tetraquarks. Measurements of the spectroscopy, decays, production, and in-medium behavior of c\bar{c}, b\bar{b}, and b\bar{c} bound states have been shown to validate some theoretical approaches to QCD and highlight lack of quantitative success for others. The intriguing details of quarkonium suppression in heavy-ion collisions that have emerged from RHIC have elevated the importance of separating hot- and cold-nuclear-matter effects in quark-gluon plasma studies. This review systematically addresses all these matters and concludes by prioritizing directions for ongoing and future efforts.Comment: 182 pages, 112 figures. Editors: N. Brambilla, S. Eidelman, B. K. Heltsley, R. Vogt. Section Coordinators: G. T. Bodwin, E. Eichten, A. D. Frawley, A. B. Meyer, R. E. Mitchell, V. Papadimitriou, P. Petreczky, A. A. Petrov, P. Robbe, A. Vair

A role for short days in sustaining seasonal reproductive activity in the ewe

International audienc

How does melatonin code for day lenght in the ewe : duration of nocturnal melatonin release or coincidence of melatonin with a light-entrained sensitive period ?

International audienc

Analýza výsledků výzkumu stimulačních systému odměňování u zakázkových strojírenských společností

<strong>Purpose of the article:</strong> This article deals with the stimulation remuneration systems of workers profession in custom engineering companies. For the first there is described theory about remuneration system of workers profession according to performance. Next the article deals with methods which are used. Than follows description of interview solution of stimulation remuneration systems for the first in terms of the respondent characteristics and survey areas and also in terms of statistical hypotheses. The main focus is to analyze data gathered from empiric survey of stimulation remuneration systems and from findings obtained from publication. This obtained findings lead to evaluation of hypotheses defined. There are presented the main results of the analysis in the discussion. <strong>Methodology/methods:</strong> In the article there are used mostly logical methods (induction, deduction, analysis, systhesis, abstraction, concretization and comparison). Further there are used methods of quantitative and qualitative research (interview survey, examining the causes and motives). From the area of statistical methods there is used particularly the research design (the way of creation data for its subsequent use), instruments for description of collected data (getting the view of the examined phenomenon) and statistical reasoning. <strong>Scientific aim:</strong> The greatest contribution of this article is the analysis of the results of empiric research of stimulation systems of custom engineering companies. Information and the results of this research became starting point for the proposal and creation of predictive model (stimulation model) of the impact of the introduction the remuneration system to the income and expenses of company. <strong>Findings:</strong> Stimulation remuneration systems are mostly created by top management of the custom engineering company. Some of the companies create specific team compound of representatives from different departments, which is responsible to create the system. From the expenses on reward of the total cost per unit point of view the different techniques of measuring the performance are quite similar. There were find further facts in the case of the responsible team for remuneration system: the team is created mostly by the custom engineering companies. The responsibility for the remuneration system is shown in whole remuneration system. The team prefers remuneration based on performance. There is higher probability of lower fluctuation, higher loyalty, monitoring the effect of the rewards to profits of the company, the company will have had bigger interest to monitor and measure the merits of the remuneration system on the increased performance of the employees, there will be more possibilities how to measure the performance. <strong>Conclusions:</strong> This submitted article deals with the remuneration of the workers professions according to the performance in custom engineering companies. The main focus is to present results of the interview survey in the area of stimulation of employees in custom engineering companies, which were evaluated in software PASW 18 and in MS Office. There is more detailed evaluation of tested hypotheses in the article. These hypotheses descripted relationships and correlations between the types of wages, responsibility for the remuneration system, the way of monitoring and evaluating the costs, the characteristics of the company, the impact of the remuneration system on costs and revenues of the company and impact of the financial crisis on the remuneration of employees. <strong></strong></p

Social cues can play a role in timing onset of the breeding season of the ewe

International audienc