RHIC and LHC jet suppression in non-central collisions

Understanding properties of QCD matter created in ultra-relativistic heavy-ion collisions is a major goal of RHIC and LHC experiments. An excellent tool to study these properties is jet suppression of light and heavy flavor observables. Utilizing this tool requires accurate suppression predictions for different experiments, probes and experimental conditions, and their unbiased comparison with experimental data. With this goal, we here extend our dynamical energy loss formalism towards generating predictions for non-central collisions; the formalism takes into account both radiative and collisional energy loss, dynamical (as opposed to static) scattering centers, finite magnetic mass, running coupling and uses no free parameters in comparison with experimental data. Specifically, we here generate predictions for all available centrality ranges, for both LHC and RHIC experiments, and for four different probes (charged hadrons, neutral pions, D mesons and non-prompt $J/\psi$). We obtain a very good agreement with all available non-central data, and also generate predictions for suppression measurements that will soon become available. Finally, we discuss implications of the obtained good agreement with experimental data with different medium models that are currently considered.Comment: 6 pages, 4 figure

Importance of higher orders in opacity in QGP tomography

We consider the problem of including a finite number of scattering centers in dynamical energy loss and classical DGLV formalism. Previously, either one or an infinite number of scattering centers were considered in energy loss calculations, while attempts to relax such approximations were largely inconclusive or incomplete. In reality, however, the number of scattering centers is generally estimated to be 4-5 at RHIC and the LHC, making the above approximations (a priori) inadequate and this theoretical problem significant for QGP tomography. We derived explicit analytical expressions for dynamical energy loss and DGLV up to the $4^{th}$ order in opacity, resulting in complex mathematical expressions that were, to our knowledge, obtained for the first time. These expressions were then implemented into an appropriately generalized DREENA framework to calculate the effects of higher orders in opacity on a wide range of high-$p_\perp$ light and heavy flavor predictions. Results of extensive numerical analysis, together with interpretations of nonintuitive results, are presented. We find that, for both RHIC and the LHC, higher-order effects on high-$p_\perp$ observables are small, and the approximation of a single scattering center is adequate for dynamical energy loss and DGLV formalisms.Comment: 23 pages, 8 figure

SYNERGISTIC EFFECTS OF INTERNAL AUDIT AND LEAN-SIX SIGMA CONCEPT ON BUSINESS PROCESS IMPROVEMENT

Abstract: Faced with a series of challenges within the environment in which they operate, companies are more than ever aware of the fact that efforts aimed at improving business processes are some of the basic conditions, not only of growth and development, but also of the survival of the company. Only in this way can the opportunities for achieving different dimensions of competitiveness be created (in terms of costs, quality, delivery reliability, speed of monitoring the changes in demand, introduction of new products, etc.). Business process improvement can be implemented with the support of a number of concepts, among them being lean-six sigma. However, the great potential in this regard also lies in internal audit. In this regard, this paper will first discuss the essence and assumptions underlying the internal audit and lean-six sigma concept, and then review the possibilities of their integration in order to achieve better results