Natural solution in the refined Gribov-Zwanziger theory

We analyse the one loop effective action of the Gribov-Zwanziger Lagrangian and use the local composite operator formalism to include the most general Becchi-Rouet-Stora-Tyutin (BRST) dimension two mass operator for the localizing ghost fields. We show that the energetically favourable colour channel corresponds to what is known as the R direction.Comment: 9 latex page

Aspects of the Gribov-Zwanziger Lagrangian in relation to gluon confinement

Over the years there have been many developments in the field of Quantum Chromodynamics, however there still remains some unresolved issues with the theory. Central to these is the principle of gauge copies arising from the Gribov problem. In this work we shall try and address some these issues, in recent years there has been a shift in the lattice data for the low momentum behaviour of the propagators for the gluon and ghost. This change suggests there may now be disagreement with the Lagrangian proposed by Gribov and Zwanziger and the lattice data. It is possible to modify the Gribov-Zwanziger Lagrangian so that it fits the lattice data but these modifications are not unique. The aim of this work is to investigate what effect these modified solutions have to our understanding of the low momentum behaviour of QCD and to see which if any of these solutions is favourable. Further to see we shall explore many of the methods and techniques used in this work by performing a calculation involving polarized deep inelastic scattering operators in QCD, this work while not related to the Gribov problem will help provide a strong understanding of many of the problems we shall encounter while considering the low momentum behaviour in the Gribov case

Similarities and differences in the historical records of lava dome-building volcanoes: implications for understanding magmatic processes and eruption forecasting

A key question for volcanic hazard assessment is the extent to which information can be exchanged between volcanoes. This question is particularly pertinent to hazard forecasting for dome-building volcanoes, where effusive activity may persist for years to decades, and may be punctuated by periods of repose, and sudden explosive activity. Here we review historical eruptive activity of fifteen lava dome-building volcanoes over the past two centuries, with the goal of creating a hierarchy of exchangeable (i.e., similar) behaviours. Eruptive behaviour is classified using empirical observations that include patterns of SO2 flux, eruption style, and magma composition. We identify two eruptive regimes: (i) an episodic regime where eruptions are much shorter than intervening periods of repose, and degassing is temporally correlated with lava effusion; and (ii) a persistent regime where eruptions are comparable in length to periods of repose and gas emissions do not correlate with eruption rates. A corollary to these two eruptive regimes is that there are also two different types of repose: (i) inter-eruptive repose separates episodic eruptions, and is characterised by negligible gas emissions and (ii) intra-eruptive repose is observed in persistently active volcanoes, and is characterised by continuous gas emissions. We suggest that these different patterns of can be used to infer vertical connectivity within mush-dominated magmatic systems. We also note that our recognition of two different types of repose raises questions about traditional definitions of historical volcanism as a point process. This is important, because the ontology of eruptive activity (that is, the definition of volcanic activity in time) influences both analysis of volcanic data and, by extension, interpretations of magmatic processes. Our analysis suggests that one identifying exchangeable traits or behaviours provides a starting point for developing robust ontologies of volcanic activity. Moreover, by linking eruptive regimes to conceptual models of magmatic processes, we illustrate a path towards developing a conceptual framework not only for comparing data between different volcanoes but also for improving forecasts of eruptive activity

Differentiation-specific nuclease of Zinnia elegans

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