Dirac zero-modes in compact U(1) gauge theory

We study properties of the zero and near-zero eigenmodes of the overlap Dirac operator in compact U(1) gauge theory. In the confinement phase the exact zero-modes are localized as found by studying the values of the inverse participation ratio and other features. Non-zero-eigenmodes are less localized in the confinement phase. In the Coulomb phase no zero-modes are observed and the eigenmodes show no localization at all.Comment: Minor corrections, 15 pages, 5 figures, LaTeX styl

Effects of nucleus initialization on event-by-event observables

In this work we present a study of the influence of nucleus initializations on the event-by-event elliptic flow coefficient, $v_2$. In most Monte-Carlo models, the initial positions of the nucleons in a nucleus are completely uncorrelated, which can lead to very high density regions. In a simple, yet more realistic model where overlapping of the nucleons is avoided, fluctuations in the initial conditions are reduced. However, $v_2$ distributions are not very sensitive to the initialization choice.Comment: 4 pages, 5 figures, to appear in the Bras. Jour. Phy

Initial Condition for QGP Evolution from NEXUS

We recently proposed a new approach to high energy nuclear scattering, which treats the initial stage of heavy ion collisions in a sophisticated way. We are able to calculate macroscopic quantities like energy density and velocity flow at the end of this initial stage, after the two nuclei having penetrated each other. In other words, we provide the initial conditions for a macroscopic treatment of the second stage of the collision. We address in particular the question of how to incorporate the soft component properly. We find almost perfect "Bjorken scaling": the rapidity coincides with the space-time rapidity, whereas the transverse flow is practically zero. The distribution of the energy density in the transverse plane shows typically a very "bumpy" structure.Comment: 17 pages, 24 figure

Remnant Break-up and Muon Production in Cosmic Ray Air Showers

We discuss the relation between remnant fragmentation in inelastic high-energy hadronic interactions and muon production in extensive cosmic ray air showers. Using a newly developed tool, a simple and flexible hadronic event generator, we analyze the forward region of hadronic interactions. We show that measurements of the Feynman-x distribution in the beam fragmentation region at LHCf will be key to understanding muon production in air showers quantitatively.Comment: 6 pages, 6 figure

Study on initial geometry fluctuations via participant plane correlations in heavy ion collisions: part II

Further investigation of the participant plane correlations within a Glauber model framework is presented, focusing on correlations between three or four participant planes of different order. A strong correlation is observed for $\cos(2\Phi_{2}^*+3\Phi_{3}^*-5\Phi_{5}^*)$ which is a reflection of the elliptic shape of the overlap region. The correlation between the corresponding experimental reaction plane angles can be easily measured. Strong correlations of similar geometric origin are also observed for $\cos(2\Phi_{2}^*+4\Phi_{4}^*-6\Phi_{6}^*)$, $\cos(2\Phi_2^*-3\Phi_3^*-4\Phi_4^*+5\Phi_5^*)$, $\cos(6\Phi_2^*+3\Phi_3^*-4\Phi_4^*-5\Phi_5^*)$, $\cos(\Phi_1^*-2\Phi_2^*-3\Phi_3^*+4\Phi_4^*)$, $\cos(\Phi_1^*+6\Phi_2^*-3\Phi_3^*-4\Phi_4^*)$, and $\cos(\Phi_1^*+2\Phi_2^*+3\Phi_3^*-6\Phi_6^*)$, which are also measurable. Experimental measurements of the corresponding reaction plane correlators in heavy ion collisions at RHIC and the LHC may improve our understanding of the physics underlying the measured higher order flow harmonics.Comment: 5 pages, 5 figure

NeXSPheRIO results on elliptic flow at RHIC and connection with thermalization

Elliptic flow at RHIC is computed event-by-event with NeXSPheRIO. Reasonable agreement with experimental results on $v_2(\eta)$ is obtained. Various effects are studied as well: reconstruction of impact parameter direction, freeze out temperature, equation of state (with or without crossover), emission mecanism.Comment: Contribution to the Proceedings of the Quark-Gluon Plasma Thermalization workshop. Content slightly increase

New Measurements and Quantitative Analysis of Electron Backscattering in the Energy Range of Neutron Beta-Decay

We report on the first detailed measurements of electron backscattering from plastic scintillator targets, extending our previous work on beryllium and silicon targets. The scintillator experiment posed several additional experimental challenges associated with charging of the scintillator target, and those challenges are addressed in detail. In addition, we quantitatively compare the energy and angular distributions of this data, and our previous data, with electron transport simulations based on the Geant4 and Penelope Monte Carlo simulation codes. The Penelope simulation is found globally to give a superior description of the data. Such information is crucial for a broad array of weak-interaction physics experiments, where electron backscattering can give rise to the dominant detector-related systematic uncertainty.Comment: 7 pages, 3 figure

VISHNU hybrid model for viscous QCD matter at RHIC and LHC energies

In this proceeding, we briefly describe the viscous hydrodynamics + hadron cascade hybrid model VISHNU for relativistic heavy ion collisions and report the current status on extracting the QGP viscosity from elliptic flow data.Comment: 4 pages, 1 figure, the proceedings of 7th International Workshop on Critical Point and Onset of Deconfinement, Wuhan, China, Nov. 7-11, 201

Vegetable production, consumption and its contribution to diets along the urban – rural continuum in Northern Ghana

Malnutrition continues to be a problem, with sub-Saharan Africa affected the worst. Women and children are at the pinnacle of this problem. The perpetual scourge of malnutrition in urban and periurban settings, coupled with levels of vegetable consumption below the recommended amounts, are a major problem in most African countries including West African cities. A household survey was conducted between November and December 2013 (dry season) in and around Tamale, Ghana as part of an urban food system analysis, to understand vegetable production and consumption and its contribution to household diets and income along the urban – rural continuum. Data collection was guided by a transect approach. A total of 240 households participated in the survey, with 62% males and 38% females. Additionally, 186 women of reproductive age (15 – 49 years) staying in the sampled households contributed to the computing of household dietary diversity through Women’s Dietary Diversity Scores (WDDS). Most vegetables produced were for subsistence use, considering that most households sold less than 50% of the crops and consumed the rest. Vegetable production varied significantly along the urban - rural continuum, with more households in rural areas producing all the requirements of their vegetables compared to urban and periurban areas. Nevertheless, the households in the rural areas (16%) had the lowest dietary diversity (≤ 3 WDDS) compared to urban areas (13%) and periurban areas (5%). The study showed low consumption of vegetables (especially the dark green vegetables) mostly in the rural area and limited diversity of vegetables, especially vitamin A rich vegetables and tubers, with only three vegetables (carrots, red pepper and sweet potato) consumed. There was evidence of more inclination toward staple crops compared to vegetables along the urban – rural continuum for both production and consumption, clearly shown in crops grown and food groups mostly consumed (cereals and tubers rather than dark green vegetables). There was overall low consumption of dark green leafy vegetables, such as amaranth, with only 26% reported to have consumed them during the reported period compared to food groups like cereals (98%). This study confirms the dual purpose of vegetables in complementing dishes (balanced diets) with much needed micronutrients and helping households along the urban – rural continuum to generate income.Keywords: Vegetables, dietary diversity, food groups, urban – rural continuum, Northern Ghan