Jet suppression in non-conformal plasma using AdS/CFT

In this paper, we study suppression of light quark in strongly coupled non-conformal plasmas using the AdS/CFT correspondence. The well-known falling string profile in the bulk is considered as light quark moving through the plasma. The maximum distance which string with energy E can travel before falling through the horizon is interpreted as thermalization distance of light quark in the hot-strongly coupled plasma. Our numerical results show that the thermalization distance of light quark increases by increasing deviation from conformal invariance. The relation between this distance and the energy of quark and the temperature of the plasma is analyzed numerically. The jet quenching parameter is also calculated in the non-conformal backgrounds and it is found that the jet quenching parameter is generally decreased by increasing the non-conformality. Our results are compared with the results of N = 4 SYM theory and also some available experimental data.Comment: 24 pages, 8 figure

Strong-coupling Jet Energy Loss from AdS/CFT

We propose a novel definition of a holographic light hadron jet and consider the phenomenological consequences, including the very first fully self-consistent, completely strong-coupling calculation of the jet nuclear modification factor $R_{AA}$, which we find compares surprisingly well with recent preliminary data from LHC. We show that the thermalization distance for light parton jets is an extremely sensitive function of the \emph{a priori} unspecified string initial conditions and that worldsheets corresponding to non-asymptotic energy jets are not well approximated by a collection of null geodesics. Our new string jet prescription, which is defined by a separation of scales from plasma to jet, leads to the re-emergence of the late-time Bragg peak in the instantaneous jet energy loss rate; unlike heavy quarks, the energy loss rate is unusually sensitive to the very definition of the string theory object itself. A straightforward application of the new jet definition leads to significant jet quenching, even in the absence of plasma. By renormalizing the in-medium suppression by that in the vacuum we find qualitative agreement with preliminary CMS $R_{AA}^{jet}(p_T)$ data in our simple plasma brick model. We close with comments on our results and an outlook on future work.Comment: 28 pages, 9 figure

Jets in a strongly coupled anisotropic plasma

In this paper, we study the dynamics of the light quark jet moving through the static, strongly coupled $\mathcal{N}=4$, anisotropic plasma with and without charge. The light quark is presented by a point-like initial condition falling string in the context of the AdS/CFT. We calculate the stopping distance of the light quark in the anisotropic medium and compare it with its isotropic value. By studying the falling string in the beam direction and transverse direction, we find that the jet quenching increases in both directions. Although, the enhancement of quenching is larger in the beam direction. Also, the suppression of stopping distance is more prominent when the anisotropic plasma have the same temperature as the isotropic plasma.Comment: Minor misprints corrected, some references added, and some figures change

The Control, environmental sustainability and information management of Maori land in New Zealand

An increase in Maori land claims and the subsequent settlement of a number of land confiscation grievances have prompted calls for change to the land management, cadastral and legal regimes in New Zealand. There is little expert agreement as to Me shape any such reforms should take, but environmental planners and Maori leaders have conceded the need for an overhaul of current land information management practices. Such reforms must aspire to being legally workable, culturally appropriate and environmentally sustainable. Most land in New Zealand is subject to recent legislation (post-1984) which acknowledges concern for Maori cultural values and ancestral rights and environmental sustainability. The existence of this legislation and growing Maori involvement in formulating public policy for the management of land and environmental resources mean that Maori concepts of land management and sustainability are receiving increasing attention and are likely to influence the shape of future cadastral reforms for Maori lands

Conservation, Market Pressures and the New Zealand Dairy Sector

The New Zealand dairy industry is a highly organised, globally marketed food production system. In order to remain internationally competitive, the industry has had to adjust to flexible price regimes and the need to achieve greater production efficiencies. At the same time, the dairy industry is based on an agricultural system grounded in ecological and social specifics that can be in conflict with business aspirations. This paper outlines some of the environmental implications of modernising New Zealand’s dairy industry, focusing on the Waikato Region, which has traditionally been a major player in the country’s dairy industry. The authors question whether the dairy industry’s growth projections, which are linked to realising greater production efficiencies, are sustainable in the long run

The socioeconomic dimensions of biosecurity: the New Zealand experience

The human dimensions of biological invasions have recently become the subject of serious study. Current insight suggests that socioeconomic arrangements can foster or restrict the introduction of new species, and create the conditions for alien species to flourish or fail. Conversely, the human response to species invasions varies, according to the economic and environmental impacts of the invasion and the institutional frameworks of the human groups affected. Using the example of New Zealand, the authors chart changes in public perception of introduced species, and assess the socio-political responses to the ecological and economic consequences of introduced and invasive species. The study also outlines the organisational changes that evolved to combat invasive organisms, and suggests that cultural perceptions and socioeconomic experience of benefits and threats have been the prime determinants of public policy on biosecurity. The authors conclude that biosecurity policies in New Zealand are primarily the outcome of a complex history of European settler aspirations and concerns which attempt to reconcile the country’s economic advantage, as a major agricultural exporter, with a desire to conserve its native flora and fauna as a hallmark of New Zealand’s unique identity and image