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

Evaluation of Forage Yield and Quality of Low-Lignin Alfalfa in Monoculture and Binary Mixtures in the Dark Brown Soil Zone of Saskatchewan

Non-Peer ReviewedThe objective of this study was to compare low-lignin Hi-Gest® 360 alfalfa to a conventional legume in both monoculture and binary mixtures. Two varieties of alfalfa (monoculture) [Medicago sativa L. cv. AC Grazeland (Grazeland) and Hi-Gest 360 (Hi-Gest] or in mixture (binary) with AC Success hybrid bromegrass (HB) (Grazeland+HB and Hi-Gest+HB) were grown at a Dark Brown soil zone site (52o07′ N, 106o 38′ W) in Saskatchewan and harvested at 3 maturity stages (stage) of alfalfa [1 = 10% bloom; 2 = 40% bloom; and 3 = 100% bloom)] over 2 yr. Forage was harvested on June 21, June 25, and June 29 2018, and July 8, July 12, and July 16 2019. All plots were established in a randomized complete block design with four replications using forages as treatments. Plot size was 6.2 m × 1.2 m (7.44 m2) with 4 rows and total of 48 plots. Dry matter yield (DMY; 2-yr) and nutritive value (1-yr) of forages were determined. Results indicate that monoculture Hi-Gest alfalfa had greater (P 0.05) for forage quantity and quality. However, forages at maturity stage 3 had greater DMY (1058 vs. 783 kg), but lower CP (17.6 vs. 19.6%) and IVNDFD48 (37.1 vs. 42.3%) than those at maturity stage 1. The sugar content of forages linearly increased (P 0.05) observed between AC Grazeland+HB and Hi-Gest+HB mixtures for DMY or quality profiles. Monoculture had greater CP (18.5 vs. 12.0 %), ADFCP (2.5 vs. 1.5%), lignin (6.9 vs. 4.7%), fat (3.0 vs. 2.6%), RFV (174.8 vs. 91.8), NEm (1.6 vs. 1.3 Mcal/kg), NEg (0.96 vs. 0.77 Mcal/kg), but lower DMY (920 vs. 3343 kg/ha), ADF (27.4 vs. 35.9%), NDF (36.3 vs. 61.9%), starch (0.41 vs. 0.82%), and IVNDFD48 (39.2 vs. 50.7%), compared to binary mixtures. Results suggest that Hi-Gest alfalfa as a monoculture yielded less than AC Grazeland, however Hi-Gest monoculture had higher nutritive value than AC Grazeland, but was similar for yield and quality in mixture, suggesting Hi-Gest 360 alfalfa is a viable alternative legume for Dark Brown soil zone of Saskatchewan

On the Integrable Structure of the Ising Model

Starting from the lattice $A_3$ realization of the Ising model defined on a strip with integrable boundary conditions, the exact spectrum (including excited states) of all the local integrals of motion is derived in the continuum limit by means of TBA techniques. It is also possible to follow the massive flow of this spectrum between the UV $c=1/2$ conformal fixed point and the massive IR theory. The UV expression of the eigenstates of such integrals of motion in terms of Virasoro modes is found to have only rational coefficients and their fermionic representation turns out to be simply related to the quantum numbers describing the spectrum.Comment: 18 pages, no figure

The Organic Research Centre; Elm Farm Bulletin 84 July 2006

Regular bulletin with technical updates of the Organic Advisory Service Issue contains: Battling on for Avian Flu preventive vaccination; Organic Colombian Blacktail eggs; UK Co-existence - GMOand non-GMO crops; Aspects of Poultry Behaviour; CAP in the service of biodiversity; Seeing the Wood, the Trees and the Catch 22; Beware of organic market "statistics"; A central role in energy review

School violence, school differences and school discourses

This article highlights one strand of a study which investigated the concept of the violenceresilient school. In six inner-city secondary schools, data on violent incidents in school and violent crime in the neighbourhood were gathered, and compared with school practices to minimise violence, accessed through interviews. Some degree of association between the patterns of behaviour and school practices was found: schools with a wider range of wellconnected practices seemed to have less difficult behaviour. Interviews also showed that the different schools had different organisational discourses for construing school violence, its possible causes and the possible solutions. Differences in practices are best understood in connection with differences in these discourses. Some of the features of school discourses are outlined, including their range, their core metaphor and their silences. We suggest that organisational discourse is an important concept in explaining school effects and school differences, and that improvement attempts could have clearer regard to this concept

Using the stated preference method for the calculation of social discount rate

The aim of this paper is to build the stated preference method into the social discount rate methodology. The first part of the paper presents the results of a survey about stated time preferences through pair-choice decision situations for various topics and time horizons. It is assumed that stated time preferences differ from calculated time preferences and that the extent of stated rates depends on the time period, and on how much respondents are financially and emotionally involved in the transactions. A significant question remains: how can the gap between the calculation and the results of surveys be resolved, and how can the real time preferences of individuals be interpreted using a social time preference rate. The second part of the paper estimates the social time preference rate for Hungary using the results of the survey, while paying special attention to the pure time preference component. The results suggest that the current method of calculation of the pure time preference rate does not reflect the real attitudes of individuals towards future generations

Voyager spacecraft radio observations of Jupiter: Initial cruise results

Jupiter's low-frequency radio emission were detected by the planetary radio astronomy instruments onboard the two Voyager spacecraft. The emission is surprisingly similar in morphology but opposite in polarization to the high-frequency Jovian radio noise that were observed with ground-based telescopes for more than two decades. Several possible explanations for the behavior of the low-frequency emission are examined, but none of them is completely satisfactory

Geometric Exponents, SLE and Logarithmic Minimal Models

In statistical mechanics, observables are usually related to local degrees of freedom such as the Q < 4 distinct states of the Q-state Potts models or the heights of the restricted solid-on-solid models. In the continuum scaling limit, these models are described by rational conformal field theories, namely the minimal models M(p,p') for suitable p, p'. More generally, as in stochastic Loewner evolution (SLE_kappa), one can consider observables related to nonlocal degrees of freedom such as paths or boundaries of clusters. This leads to fractal dimensions or geometric exponents related to values of conformal dimensions not found among the finite sets of values allowed by the rational minimal models. Working in the context of a loop gas with loop fugacity beta = -2 cos(4 pi/kappa), we use Monte Carlo simulations to measure the fractal dimensions of various geometric objects such as paths and the generalizations of cluster mass, cluster hull, external perimeter and red bonds. Specializing to the case where the SLE parameter kappa = 4p'/p is rational with p < p', we argue that the geometric exponents are related to conformal dimensions found in the infinitely extended Kac tables of the logarithmic minimal models LM(p,p'). These theories describe lattice systems with nonlocal degrees of freedom. We present results for critical dense polymers LM(1,2), critical percolation LM(2,3), the logarithmic Ising model LM(3,4), the logarithmic tricritical Ising model LM(4,5) as well as LM(3,5). Our results are compared with rigourous results from SLE_kappa, with predictions from theoretical physics and with other numerical experiments. Throughout, we emphasize the relationships between SLE_kappa, geometric exponents and the conformal dimensions of the underlying CFTs.Comment: Added reference

Voyager 1 Planetary Radio Astronomy Observations Near Jupiter

Results are reported from the first low frequency radio receiver to be transported into the Jupiter magnetosphere. Dramatic new information was obtained both because Voyager was near or in Jupiter's radio emission sources and also because it was outside the relatively dense solar wind plasma of the inner solar system. Extensive radio arcs, from above 30 MHz to about 1 MHz, occurred in patterns correlated with planetary longitude. A newly discovered kilometric wavelength radio source may relate to the plasma torus near Io's orbit. In situ wave resonances near closest approach define an electron density profile along the Voyager trajectory and form the basis for a map of the torus. Studies in progress are outlined briefly