Coupling Constants for Scalar Glueball Decay

We evaluate the partial decay widths of the lightest scalar glueball to pairs of pseudoscalar quark-antiquark states. The calculation is done in the valence (quenched) approximation on a 16^3 \time 24 lattice at $\beta = 5.7$. These predictions and values obtained earlier for the infinite volume continuum limit of the scalar glueball's mass are in good agreement with the observed properties of $f_J(1710)$ and inconsistent with all other observed meson resonances.Comment: 8 pages of Latex, 12 PostScript figures, 2 macros included, plenary talk given by D. Weingarten at Lattice 95, to appear in conference proceeding

Fall Risk Increasing Drugs: The Effect on Injuries of the Frail Elderly Estimated from Administrative Data

Society benefits on a large scale from improved medical care and pharmaceuticals. The prescription of pharmaceuticals, however, also carries risks such as the possibility of an increased risk of falls, which may lead to severe injuries and increased health expenditures associated with these injuries. This study investigates the influence of several fall risk increasing drugs (FRIDs) on the number of injuries of elderly persons using multivariate regression models. Routine data from the Techniker Krankenkasse (TK) of frail elderly persons aged Ï 65 years is analyzed for the year 2009 by estimating count data models, in order to take the data generating process of the number of injuries into account. The results of the count data model are compared to those from logistic regressions, which is the default regression model in this fi eld of research. The empirical results suggest that antidepressants, anxiolytics, hypnotics and sedatives, antiarrhythmics, and drugs from the Priscus-list have a signifi cant positive effect on the number of injuries, while antihypertensives and anti-parkinsonian agents show no and neuroleptics a significant negative eff ect. As recurrent injuries are common, the analysis of the number of injuries rather than just the probability of having an injury provides a more informative analysis of FRIDs.Flächendeckende medizinische Versorgung und eine verbesserte Pharamkotherapie haben dazu geführt, dass die Lebenserwartung in den vergangenen Jahrzehnten stetig gestiegen ist. Dennoch ist die Einnahme von Medikamenten nicht ausschließlich nutzenbringend, sondern kann für gewisse Personengruppen mit Risiken und hohen Nachbehandlungskosten einhergehen. Deshalb verwendet diese Studie Routinedaten der Techniker Krankenkasse, um den Einfluss von sturzrisikofördernden Medikamenten, auf die Anzahl von Verletzungen bei älteren Menschen ab einem Alter von 65 Jahren zu untersuchen. Für die Schätzung werden im Gegensatz zur existierenden Literatur anstelle von Logit Modellen, Count Data Modelle verwendet, die die besondere, hier vorliegende Datenstruktur berücksichtigen. Die empirischen Ergebnisse zeigen, dass bestimmte Medikamentengruppen, wie Antidepressiva, Anxiolytika, Hypnotika und Sedativa, Antiarrhythmika sowie Medikamente der Priscus-Liste einen positiv signifikanten Einfluss auf die Anzahl von Verletzungen haben, wohingegen der Einfluss von Antihypertensiva und Antiparkinson Mittel insignifikant ist. Demnach ist vor allem bei der Verschreibung der erstgenannten Medikamentengruppen besondere Vorsicht geboten und eine Abwägung der Risiken und des Nutzen von Nöten

Numerical Evidence for the Observation of a Scalar Glueball

We compute from lattice QCD in the valence (quenched) approximation the partial decay widths of the lightest scalar glueball to pairs of pseudoscalar quark-antiquark states. These predictions and values obtained earlier for the scalar glueball's mass are in good agreement with the observed properties of $f_J(1710)$ and inconsistent with all other observed meson resonances.Comment: 12 pages of Latex, 3 PostsScript figures as separate uufil

A comprehensive lattice study of SU(3) glueballs

We present a study of the $SU(3)$ glueball spectrum for all $J^{PC}$ values at lattice spacings down to $a^{-1}=3.73 (6)$ GeV ($\beta=6.4$) using lattices of size up to $32^4$. We extend previous studies and show that the continuum limit has effectively been reached. The number of clearly identified $J^{PC}$ states has been substantially increased. There are no clear signals for spin-exotic glueballs below 3 GeV. A comparison with current experimental glueball candidates is made.Comment: 10 pages including 2 PS figures, Liverpool Preprint: LTH 303, Wuppertal Preprint: WUB 93-1

Unquenching the scalar glueball

Computations in the quenched approximation on the lattice predict the lightest glueball to be a scalar in the 1.5-1.8 GeV region. Here we calculate the dynamical effect the coupling to two pseudoscalars has on the mass, width and decay pattern of such a scalar glueball. These hadronic interactions allow mixing with the $q \overline q$ scalar nonet, which is largely fixed by the well-established K_0^*(1430). This non-perturbative mixing means that, if the pure gluestate has a width to two pseudoscalar channels of ~100 MeV as predicted on the lattice, the resulting hadron has a width to these channels of only ~30 MeV with a large eta-eta component. Experimental results need to be reanalyzed in the light of these predictions to decide if either the f_0(1500) or an f_0(1710) coincides with this dressed glueball.Comment: 12 pages, LaTex, 3 Postscript figure

On the structure of the scalar mesons f0(975)f_0(975) and a0(980)a_0(980)

We investigate the structure of the scalar mesons $f_0(975)$ and $a_0(980)$ within realistic meson-exchange models of the $\pi\pi$ and $\pi\eta$ interactions. Starting from a modified version of the J\"ulich model for $\pi\pi$ scattering we perform an analysis of the pole structure of the resulting scattering amplitude and find, in contrast to existing models, a somewhat large mass for the $f_0(975)$ ($m_{f_0}=1015$ MeV, $\Gamma_{f_0}=30$ MeV). It is shown that our model provides a description of $J/\psi\rightarrow\phi\pi\pi/\phi KK$ data comparable in quality with those of alternative models. Furthermore, the formalism developed for the $\pi\pi$ system is consistently extended to the $\pi\eta$ interaction leading to a description of the $a_0(980)$ as a dynamically generated threshold effect (which is therefore neither a conventional $q\overline{q}$ state nor a $K\overline{K}$ bound state). Exploring the corresponding pole position the $a_0(980)$ is found to be rather broad ($m_{a_0}=991$ MeV, $\Gamma_{a_0}=202$ MeV). The experimentally observed smaller width results from the influence of the nearby $K\overline{K}$ threshold on this pole.Comment: 25 pages, 15 Postscript figure

Observing Spontaneous Strong Parity Violation in Heavy-Ion Collisions

We discuss the problem of observing spontaneous parity and CP violation in collision systems. We discuss and propose observables which may be used in heavy-ion collisions to observe such violations, as well as event-by-event methods to analyze the data. Finally, we discuss simple monte-carlo models of these CP violating effects which we have used to develop our techniques and from which we derive rough estimates of sensitivities to signals which may be seen at RHIC

The two-pion spectra for the reaction \pi^- p -> \pi^0\pi^0 n at 38 GeV/c pion momentum and combined analysis of the GAMS, Crystal Barrel and BNL data

We perform the K-matrix analysis of meson partial waves with IJ^{PC} =00^{++}, 10^{++}, 02^{++}, 12^{++} basing on GAMS data on \pi^-p -> \pi^0\pi^0 n, \eta\eta n, \eta\eta' n together with BNL data on \pi^-p -> K\bar K n and Crystal Barrel data on p\bar p (at rest) -> \pi^0\pi^0\pi^0, \pi^0\eta\eta, \pi^0\pi^0\eta. The positions of the amplitude poles (physical resonances) are determined as well as the positions of the K-matrix poles (bare states) and the values of bare state couplings to two-meson channels. Nonet classification of the determined bare states is discussed.Comment: LaTex, 15 pages and 10 figure