Isospin Fluctuations from a Thermally Equilibrated Hadron Gas

Partition functions, multiplicity distributions, and isospin fluctuations are calculated for canonical ensembles in which additive quantum numbers as well as total isospin are strictly conserved. When properly accounting for Bose-Einstein symmetrization, the multiplicity distributions of neutral pions in a pion gas are significantly broader as compared to the non-degenerate case. Inclusion of resonances compensates for this broadening effect. Recursion relations are derived which allow calculation of exact results with modest computer time.Comment: 10 pages, 5 figure

The Quark-Gluon Plasma in a Finite Volume

The statistical mechanics of quarks and gluons are investigated within the context of the canonical ensemble. Recursive techniques are developed which enforce the exact conservation of baryon number, total isospin, electric charge, strangeness, and color. Bose and Fermi-Dirac statistics are also accounted for to all orders. The energy, entropy and particle number densities are shown to be significantly reduced for volumes less than 5 cubic fm.Comment: 8 pages, 3 figure

Statistical Models of Nuclear Fragmentation

A method is presented that allows exact calculations of fragment multiplicity distributions for a canonical ensemble of non-interacting clusters. Fragmentation properties are shown to depend on only a few parameters. Fragments are shown to be copiously produced above the transition temperature. At this transition temperature, the calculated multiplicity distributions broaden and become strongly super-Poissonian. This behavior is compared to predictions from a percolation model. A corresponding microcanonical formalism is also presented.Comment: 12 pages, 5 figure

Model of multifragmentation, Equation of State and phase transition

We consider a soluble model of multifragmentation which is similar in spirit to many models which have been used to fit intermediate energy heavy ion collision data. We draw a p-V diagram for the model and compare with a p-V diagram obtained from a mean-field theory. We investigate the question of chemical instability in the multifragmentation model. Phase transitions in the model are discussed.Comment: Revtex, 9 pages including 6 figures: some change in the text and Fig.

On religion and cultural policy: notes on the Roman Catholic Church

This paper argues that religious institutions have largely been neglected within the study of cultural policy. This is attributed to the inherently secular tendency of most modern social sciences. Despite the predominance of the ‘secularisation paradigm’, the paper notes that religion continues to promote powerful attachments and denunciations. Arguments between the ‘new atheists’, in particular, Richard Dawkins, and their opponents are discussed, as is Habermas’s conciliatory encounter with Joseph Ratzinger (later Pope Benedict XVI). The paper then moves to a consideration of the Roman Catholic Church as an agent of cultural policy, whose overriding aim is the promotion of ‘Christian consciousness’. Discussion focuses on the contested meanings of this, with reference to (1) the deliberations of Vatican II and (2) the exercise of theological and cultural authority by the Pope and the Congregation for the Doctrine of the Faith (CDF). It is argued that these doctrinal disputes intersect with secular notions of social and cultural policy and warrant attention outside the specialist realm of theological discourse

The MACHO Project 2nd Year LMC Microlensing Results and Dark Matter Implications

The MACHO Project is searching for galactic dark matter in the form of massive compact halo objects (Machos). Millions of stars in the Large Magellanic Cloud (LMC), Small Magellanic Cloud (SMC), and Galactic bulge are photometrically monitored in an attempt to detect rare gravitational microlensing events caused by otherwise invisible Machos. Analysis of two years of photometry on 8.5 million stars in the LMC reveals 8 candidate microlensing events, far more than the $\sim1$ event expected from lensing by low-mass stars in known galactic populations. From these eight events we estimate the optical depth towards the LMC from events with 2 < \that < 200 days to be \tau_2^{200} \approx 2.9 ^{+1.4}_{-0.9} \ten{-7}. This exceeds the optical depth of 0.5\ten{-7} expected from known stars and is to be compared with an optical depth of 4.7\ten{-7} predicted for a ``standard'' halo composed entirely of Machos. The total mass in this lensing population is \approx 2^{+1.2}_{-0.7} \ten{11} \msun (within 50 kpc from the Galactic center). Event timescales yield a most probable Macho mass of 0.5^{+0.3}_{-0.2}\msun, although this value is quite model dependent.Comment: 10 pages, 6 epsf figures and style file included, 451k, also at http://wwwmacho.mcmaster.ca/Pubs/Pubs.html; To appear in the Proceedings of "Sources and Detection of Dark Matter in the Universe", Santa Monica, CA, Feb., 199

A Binary Lensing Event Toward the LMC: Observations and Dark Matter Implications

The MACHO collaboration has recently analyzed 2.1 years of photometric data for about 8.5 million stars in the Large Magellanic Cloud (LMC). This analysis has revealed 8 candidate microlensing events and a total microlensing optical depth of $\tau_{meas} = 2.9 +1.4/-0.9 \times 10^{-7}$. This significantly exceeds the number of events (1.1) and the microlensing optical depth predicted from known stellar populations: $\tau_{back} = 5.4\times 10^{-8}$, but it is consistent with models in which about half of the standard dark halo mass is composed of Machos of mass \sim 0.5 \msun. One of these 8 events appears to be a binary lensing event with a caustic crossing that is partially resolved which allows us to estimate the distance to the lenses. If the source star is not a short period binary star, then we show that the lens system is very likely to reside in the LMC. However, if we assume that the optical depth for LMC-LMC lensing is large enough to account for our entire lensing signal, then the binary event does not appear to be consistent with lensing of a single LMC source star by a binary residing in the LMC. Thus, while the binary lens may indeed reside in the LMC, there is no indication that most of the lenses reside in the LMC.Comment: 5 pages, 3 postscript figures included; To appear in the Proceedings of the Dark Matter '96 Conference held in Santa Monica, CA, Feb., 199

Ação do cepa e do ácido giberélico na frutificação da videira 'niagara rosada'

Studies were carried out to establish the effects of exogenous growth regulators on Vitis (labrusca x vinifera) 'Niagara Rosada' fruiting. The investigations were done in the Jundiaí Research Station, Agronomic Institute State of São Paulo, always using disease-free vineyards of good productivity. The morphological transformations of clusters were carried out under the following aspects: weight, length and width of cluster; number of berries; weight, length average and width average of berries; length average/width average ratio of berries; number of seeds; length and diameter of secondary rachis. That characteristics were determined at the time of maturity plus the total sugars, total acid, Maturity Index and reducing sugars in samples of all treatments. The experiment were conduced in order to determine the doses that resulted in the most beneficial effects, always using applications by immersion of the inflorescence. The experiment consisted of appplications of (2-chloroethyl) phosphonic acid (CEPA) at concentrations of 50, 100, 250, 500, 1,000 and 2,000 ppm, 14 days before flowering; treatments with gibberellic acid at concentrations of 100 and 200 ppm before full bloom, 10 days after full bloom, and both before plus after full bloom. Treatment with CEPA 100 ppm plus gibberellic acid 100 ppm before full bloom and check treatment were also used. The use of CEPA before flowering at the concentrations used, did not result in good results in 'Niagara Rosada' clusters; applications of gibberellic acid did not differ significantly from the nontreated vines under the conditions studied.Estudou-se o efeito da aplicação, por imersão, do CEPA (ácido 2-cloroetil fosfônico) e do ácido giberélico, 14 dias antes do florescimento, nas características morfológicas da panícula da videira Vitis (labrus-ca x vinifera) "Niagara Rosada". Alguns tratamentos com ácido giberélico foram concluídos com nova aplicação 10 dias após o florescimento. Neste experimento verificou-se que, aplicação do CEPA na concentração de 250 ppm resultou na formação de panículas com a maioria de características indesejáveis. o tratamento misto CEPA 100 ppm + ácido giberélico 100 ppm também promoveu o aparecimento de panículas subdesenvolvidas. Aplicação de ácido giberélico na concentração de 100 ppm em pré e pós-ílorescimento, resultou médias mais elevadas, com relação ao peso da panícula, comprimento da panícula, peso das bagas e comprimento da ráquis. Ácido giberélico na concentração de 100 ppm aplicado em pós-ílorescimento, promoveu uma tendência de aumento nas médias do tratamento quanto ao comprimento médio das bagas, largura média das bagas, largura do engaço e comprimento da ráquila. Devemos considerar porém, que os resultados obtidos não apresentaram diferenças significativas com relação ao controle, quanto às características das frutificações, nas condições de estudo

Overview of the Alaskan Layered Pollution and Chemical Analysis (ALPACA) Field Experiment

The Alaskan Layered Pollution And Chemical Analysis (ALPACA) field experiment was a collaborative study designed to improve understanding of pollution sources and chemical processes during winter (cold climate and low-photochemical activity), to investigate indoor pollution, and to study dispersion of pollution as affected by frequent temperature inversions. A number of the research goals were motivated by questions raised by residents of Fairbanks, Alaska, where the study was held. This paper describes the measurement strategies and the conditions encountered during the January and February 2022 field experiment, and reports early examples of how the measurements addressed research goals, particularly those of interest to the residents. Outdoor air measurements showed high concentrations of particulate matter and pollutant gases including volatile organic carbon species. During pollution events, low winds and extremely stable atmospheric conditions trapped pollution below 73 m, an extremely shallow vertical scale. Tethered-balloon-based measurements intercepted plumes aloft, which were associated with power plant point sources through transport modeling. Because cold climate residents spend much of their time indoors, the study included an indoor air quality component, where measurements were made inside and outside a house to study infiltration and indoor sources. In the absence of indoor activities such as cooking and/or heating with a pellet stove, indoor particulate matter concentrations were lower than outdoors; however, cooking and pellet stove burns often caused higher indoor particulate matter concentrations than outdoors. The mass-normalized particulate matter oxidative potential, a health-relevant property measured here by the reactivity with dithiothreiol, of indoor particles varied by source, with cooking particles having less oxidative potential per mass than pellet stove particles