Soft Contribution to the Hard Ridge in Relativistic Nuclear Collisions

Nuclear collisions exhibit long-range rapidity correlations not present in proton-proton collisions. Because the correlation structure is wide in relative pseudorapidity and narrow in relative azimuthal angle, it is known as the ridge. Similar ridge structures are observed in correlations of particles associated with a jet trigger (the hard ridge) as well as correlations without a trigger (the soft ridge). Earlier we argued that the soft ridge arises when particles formed in an early Glasma stage later manifest transverse flow. We extend this study to address new soft ridge measurements. We then determine the contribution of flow to the hard ridge.Comment: 16 pages, 9 figures, includes comparison to dat

Estimation of shear viscosity based on transverse momentum correlations

Event anisotropy measurements at RHIC suggest the strongly interacting matter created in heavy ion collisions flows with very little shear viscosity. Precise determination of "shear viscosity-to-entropy" ratio is currently a subject of extensive study. We present preliminary results of measurements of the evolution of transverse momentum correlation function with collision centrality of $Au +Au$ interactions at $\sqrt{s_{NN}}$ = 200 GeV. We compare two differential correlation functions, namely {\it inclusive} and a differential version of the correlation measure $\tilde C$ introduced by Gavin ${\it et. al.}$. These observables can be used for the experimental study of the shear viscosity per unit entropy.Comment: 4 pages, 8 figures, proceedings re-submitted for Quark Matter 2009 conference. This paper contains revision of one of the figure

Improving Adoptive Mergers at River Community Church

This thesis project cross compared the adoptive mergers of River Community Church (RCC) to identify the methodologies and strategies that created one successful campus via adoptive merger and a subsequent unsuccessful campus. Empirical analysis quantified the gap in success between RCC Chesterfield and RCC Fairway. Qualitative research provided the thematic points of differentiation in RCC’s adoptive merger implementations. The thematic findings detailed a potential revitalization plan for RCC Fairway, a common structure for future RCC adoptive merger considerations, and insight for churches contemplating adoptive merger pursuits

The Rise and Fall of the Ridge

Recent data from heavy ion collisions at RHIC show unexpectedly large near-angle correlations that broaden longitudinally with centrality. The amplitude of this ridge-like correlation rises rapidly with centrality, reaches a maximum, and then falls in the most central collisions. In this talk we explain how this behavior can be easily understood in a picture where final momentum-space correlations are driven by initial coordinate space density fluctuations. We propose $v_n^2/\epsilon_{n,part}^{2}$ as a useful way to study these effects and explain what it tells us about the collision dynamics.Comment: 6 pages, 5 figures, proceedings for Hard Probes 2010 in Eilat, Israe

Analyzing the Power Spectrum of the Little Bangs

In this talk we discuss the analogy between data from heavy-ion collisions and the Cosmic Microwave Background. We identify p_T correlations data as the heavy-ion analogy to the CMB and extract a power-spectrum from the heavy-ion data. We define the ratio of the final state power-spectrum to the initial coordinate-space eccentricity as the transfer-function. From the transfer-function we find that higher $n$ terms are suppressed and we argue that the suppression provides information on length scales like the mean-free-path. We make a rough estimate of the mean-free-path and find that it is larger than estimates based on the centrality dependence of v_2.Comment: 4 pages, talk given at Hard Probes 2010, Eilat, Israe

Transverse radial expansion in nuclear collisions and two particle correlations

At the very first stage of an ultra-relativistic nucleus-nucleus collision new particles are produced in individual nucleon-nucleon collisions. In the transverse plane, all particles from a single $NN$ collision are initially located at the same position. The subsequent thermalization and transverse radial expansion of the system create strong position-momentum correlations and lead to characteristic rapidity, transverse momentum, and azimuthal correlations among the produced particles.Comment: As accepted for publication in Phys. Lett. B. The discussion is slightly extended. The linear scale in Fig.2 changed to log scale. No other change

An impact study of the competency and placement (CAP) test intervention at further education and training (FET) colleges

The research undertaken involves a quasi-experimental approach in determining the impact of the Competency and Placement (CAP) test in the Further Education and Training (FET) colleges. The evaluation became necessary because poor learner performance within the National Certification Vocational (NCV) programme has persisted amid the implementation of a country-wide roll-out of the CAP test; and a recapitalisation injection of R1.9m. Learner performance data relating to the NCV programme and CAP was obtained in order to undertake an accurate analysis of the poor performance within the FET college sector. In addition to the above, qualitative data was obtained through semi-structured interviews with CAP participating colleges in the country. Recommendations included the restructuring of the NCV programme; the introduction of an alternative learner placement methodology that was in line with international best practices; and improving quality assurance aspects pertaining to the capacity at colleges to deliver the NCV programme effectively.Human Resources DevelopmentM. Tech. (Human Resource Development

Transverse Radial Flow Effects on Two- and Three-Particle Angular Correlations

We use a simple a transverse radial boost scenario coupled to PYTHIA events to illustrate the impact radial flow may have on two- and three-particle correlation functions measured in heavy-ion collisions. We show that modest radial velocities can impart strong modifications to the correlation functions, some of which may be interpreted as same side ridge and away side structure that can mimic conical emission.Comment: 7 figures, 9 pages, Material presented in part by Pruneau at HOC 07, Montreal, Canada Accepted for publication in Nucl Phys A (Jan 2008

Quarkonium production via recombination

The contrast between model predictions for the transverse momentum spectra of J/Psi observed in Au-Au collisions at RHIC is extended to include effects of nuclear absorption. We find that the difference between initial production and recombination is enhanced in the most central collisions. Models utilizing a combination of these sources may eventually be able to place constraints on their relative magnitudes.Comment: Based on invited plenary talk at the 2nd International Conference on Hard and Electromagnetic Probes of High-Energy Nuclear Collisions, Asilomar, CA, June 9-16, 2006, to be published in Nucl. Phys.