BFKL equation with running QCD coupling and HERA data

In this paper we developed approach based on the BFKL evolution in \ln\Lb Q^2\Rb. We show that the simplest diffusion approximation with running QCD coupling is able to describe the HERA experimental data on the deep inelastic structure function with good $\chi^2/d.o.f. \approx 1.3$. From our description of the experimental data we learned several lessons; (i) the non-perturbative physics at long distances started to show up at $Q^2 = 0.25\,GeV^2$; (ii) the scattering amplitude at $Q^2 = 0.25\,GeV^2$ cannot be written as sum of soft Pomeron and the secondary Reggeon but the Pomeron interactions should be taken into account; (iii) the Pomeron interactions can be reduced to the enhanced diagrams and, therefore, we do not see any needs for the shadowing corrections at HERA energies; and (iv) we demonstrated that the shadowing correction could be sizable at higher than HERA energies without any contradiction with our initial conditions.Comment: 16pp,14 figures in eps.file

Approaches to integrate land-use and transport planning: Analysing the political dimension of integrative planning

Spatial structures influence our travel distances between home, work, shopping or leisure and determine our mobility behaviour to a considerable extent. Although they are not the only determinants of our daily travel distances and times or our choice of different means of transport, the interrelations between spatial structures and mobility behaviour is often considered in the literature. Overall, the integration of land use and transportation planning is a key aspect in the shift towards sustainable mobility. This integrated planning approach is characterised, for instance, by increased cross-sector interaction, softened institutionalised boundaries between the two sectors of land-use and transportation planning, and shared cross-sector goals. In its implementation, however, this frequently postulated call for integration remains unclear. This paper uses the conceptual framework of the three dimensions of policy, polity and politics to empirically capture this integration in its various aspects. The two German cities of Dortmund and Hannover serve as case studies. The findings suggest that informal interaction (politics) between the two sectors is a necessary precondition for integration, while political will and cross-sectorally shared strategic goals (policy) are required to actually set the process of integration in motion. Ultimately, an approach is fully integrated when institutional structures (polity) are adapted in the sense of hierarchical coordination and the extensive elimination of sectoral boundaries.Räumliche Strukturen beeinflussen, welche Wege wir zwischen Wohnort, Arbeitsort, Einkaufsmöglichkeiten oder Freizeitvergnügen zurücklegen und bestimmen in erheblichem Maße unser Mobilitätsverhalten. Zwar sind sie nicht allein bestimmend über unsere täglichen Wegstrecken und Weglängen sowie unsere Wahl der Verkehrsmittel, doch wird der Zusammenhang zwischen räumlichen Strukturen und dem Mobilitätsverhalten in der Literatur stets aufgenommen. Schlussfolgernd ist die Integration von Flächennutzungs- und Verkehrsplanung ein zentraler Aspekt im Wandel hin zu einer nachhaltigen Mobilität. Dieser integrierte Planungsansatz zeichnet sich beispielsweise durch verstärkte sektorübergreifende Interaktion, aufgeweichte institutionalisierte Grenzen zwischen den beiden Sektoren der Flächennutzungs- und Verkehrsplanung sowie gemeinsame sektorübergreifende Ziele aus. In ihrer Umsetzung bleibt diese häufig postulierte Forderung nach Integration jedoch unklar. Dieser Beitrag nutzt den konzeptionellen Rahmen der drei Politikdimensionen Policy, Polity und Politics, um diese Integration in ihren verschiedenen Aspekten auch empirisch zu erfassen. Als Fallstudien dienen die beiden deutschen Städte Dortmund und Hannover. Ergebnis ist, dass informelle Interaktion (Politics) zwischen beiden Sektoren eine notwendige Voraussetzung für Integration ist, während politischer Wille und sektorübergreifend geteilte strategische Ziele (Policy) erforderlich sind, um den Prozess der Integration tatsächlich in Gang zu setzen. Letztlich ist ein Ansatz dann vollständig integriert, wenn institutionelle Strukturen (Polity) im Sinne einer hierarchischen Koordination und einer weitgehenden Aufhebung sektoraler Grenzen angepasst werden

DGLAP evolution for DIS diffraction production of high masses

In this paper we develop the DGLAP evolution for the system of produced gluons in the process of diffractive production in DIS, directly from the evolution equation in Color Glass Condensate approach. We are able to describe the available experimental data with small value of the QCD coupling ($\bar{\alpha_S} \approx 0.1$). We conclude that in diffractive production, we have a dilute system of emitted gluons and in the order to describe them, we need to develop the next-to-leading order approach in perturbative QCD.Comment: 20 pp. 7 figs in eps files. arXiv admin note: text overlap with arXiv:1802.0634

CGC/saturation approach: an impact-parameter dependent model for diffraction production in DIS

In the paper we discussed the evolution equations for diffractive production in the framework of CGC/saturation approach, and found the analytical solutions for several kinematic regions. The most impressive features of these solutions are, that diffractive production does not exibit geometric scaling behaviour i.e. being a function of one variable. Based on these solutions, we suggest an impact parameter dependent saturation model, which is suitable for describing diffraction production both deep in the saturation region, and in the vicinity of the saturation scale. Using the model we attempted to fit the combined data on diffraction production from H1 and ZEUS collaborations. We found that we are able describe both x_\pom and $\beta$ dependence, as well as $Q$ behavior of the measured cross sections. In spite of the sufficiently large $\chi^2/d.o.f.$ we believe that our description provides an initial impetus to find a fit of the experimental data, based on the solution of the CGC/saturation equation, rather than on describing the diffraction system in simplistic manner, assuming that only quark-antiquark pair and one extra gluons, are produced.Comment: 20pp. 14 figures in eps forma

Chaotic advection in an archipelago

Author Posting. © American Meteorological Society, 2010. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Physical Oceanography 40 (2010): 1988–2006, doi:10.1175/2010JPO4336.1.Techniques from dynamical systems theory have been applied to study horizontal stirring of fluid in the Philippine Archipelago. The authors’ analysis is based on velocity fields produced by two high-resolution (3 and 6 km) numerical models. Particular attention is paid to identifying robust surface flow patterns and associating them with dominant Lagrangian coherent structures (LCSs). A recurrent wind-driven dipole in the lee of the coastline is considered in detail. The associated LCSs form a template for stirring, exchange, and biological transport in and around the dipole. Chaotic advection is argued to provide a relevant framework for interpreting mesoscale horizontal stirring processes in an archipelago as a whole. Implications for the formation of filaments, the production of tracer variance, and the scale at which stirring leads to mixing are discussed in connection with an observed temperature record.This work was supported by the Office of Naval Research: Grant N00014-07-1-0590 to Woods Hole Oceanographic Institution; Grant ONR- 0601153N to Stevens Institute of Technology; Grant N00014-07-1-0417 to Institute of Marine and Coastal Sciences, Rutgers University; and Grant N00014-09-1- 0582 to Lamont-Doherty Earth Observatory of Columbia University