Confining properties of QCD at finite temperature and density

A disorder parameter detecting dual superconductivty of the vacuum is used as a probe to characterize the confining properties of the phase diagram of two color QCD at finite temperature and density. We obtain evidence for the disappearing of dual superconductivity (deconfinement) induced by a finite density of baryonic matter, as well as for a coincidence of this phenomenon with the restoration of chiral symmetry both at zero and finite density. The saturation transition induced by Pauli blocking is studied as well, and a general warning is given about the possible effects that this unphysical transition could have on the study of the QCD phase diagram at strong values of the gauge coupling.Comment: 13 pages, 23 figure

Growth divergence and income inequality in OECD countries: the role of trade and financial openness. LEQS Paper No. 148/2018 October 2019

This paper analyses trade and financial openness effects on growth and income inequality in 35 OECD countries. Our model takes into account both short run and long run effects of factors explaining income divergence between and within the countries. We estimate, for the period 1995-2016, an error correction model in which per capita GDP and inequality are driven by changes over time of selected factors and by the deviation from a long run relationship. Stylised facts suggest that trade and financial openness reduce the growth gaps across the countries but not income inequality, and the effects of finance are stronger in high income countries. Nevertheless, low and middle income countries benefit more from international trade. Our contribution to the existing literature is threefold: i) we study the short and long run effects of trade and financial openness on income level and distribution, ii) we focus on developed countries (OECD) rather than on developing and iii) we provide a sensitivity analysis including in our baseline equation an institutional indicator, a trade agreement proxy and a dummy of global financial crisis. Estimates results indicate that trade openness significantly improved the conditions of OECD low income countries both in short and long run mostly, consistently with the catching up theory. It also decreased inequality, but only in low and middle income countries. Differently financial openness had a positive and significant impact only in the short run on middle income countries and increased income disparities within countries in the short term in low income countries and in the long term in high income countries

The order of the Roberge-Weiss endpoint (finite size transition) in QCD

We consider the endpoint of the Roberge-Weiss (RW) first order transition line present for imaginary baryon chemical potentials. We remark that it coincides with the finite size transition relevant in the context of large $N_c$ QCD and study its order in the theory with two degenerate flavors. The RW endpoint is first order in the limit of large and small quark masses, while it weakens for intermediate masses where it is likely in the Ising 3d universality class. Phenomenological implications and further speculations about the QCD phase diagram are discussed.Comment: 5 pages, 8 figures. Version accepted for publication in Physical Review D (R

Closing Remarks: The Three Pillars of Energy

Coal, crude oil, and natural gas are very precious resources because they are non-renewable. If renewable energy sources were not available, fossil fuels would support the modern economy. However, if fossil fuels were unavailable, then the economic system would collapse quickly. Technological advances, economic theory, and experience point to significant barriers that challenge the development of renewables

Everyday Enactments of Resistance : Portraits of Secondary Public School Teachers Navigating New Professionalism

New professionalism has changed the roles and responsibilities of teachers. It has created a professional culture that prioritizes managerialism, bureaucracy, standardization and assessment, and performance review. This shift has created tension and anxiety amongst teachers, but a population of teachers continue to openly question, resist, or protest directives that do not align with their goals and values. The goal of this study was to gain understanding of the lived experiences of veteran, secondary, public school teachers who have attempted to find ways to navigate and resist new professionalism. Using Sara Lawrence-Lightfoot’s portraiture method, participants’ narratives bring life to the ways these veteran teachers have endeavored to make decisions about their profession. The insights gained from these participants’ portraits have implications for teacher education and future research on veteran teacher resistance

Susceptibility of the QCD vacuum to CP-odd electromagnetic background fields

We investigate two flavor QCD in presence of CP-odd electromagnetic background fields and determine, by means of lattice QCD simulations, the induced effective theta term to the first order in the scalar product of E and B. We employ a rooted staggered discretization and study lattice spacings down to 0.1 fm and Goldstone pion masses around 480 MeV. In order to deal with a positive measure, we consider purely imaginary electric fields and real magnetic fields, then exploiting analytic continuation. Our results are relevant to a description of the effective pseudoscalar QED-QCD interactions.Comment: 5 pages, 4 figures, 1 table. New data and references added. Matches the published versio

New Teacher Induction : Locating New Teacher Needs to Co-Construct Induction Programs

This study focused on the transition period from pre-service to teaching known as new teacher induction. Using new teacher voices within third space qualitative interviews to better understand how new teachers made sense of their induction period within a school district, the findings from this study suggest that new teachers are not only faced with immediate and longterm needs that they must fulfill, but also new teachers must make sense of their school environments and the micropolitical atmospheres they must work in. Using the voices of new teachers and teacher coaches within a school district, this study examined how districts can better understand what new teachers experience as they transition into a school or district. The understanding of this liminal stage in a teacher’s career is essential for policymakers, pre-service educators, pre-service teachers, administrators, and perhaps most importantly, veteran teachers if we hope to curb high attrition rates and the effects such have on our students and schools

Direct numerical computation of disorder parameters

In the framework of various statistical models as well as of mechanisms for color confinement, disorder parameters can be developed which are generally expressed as ratios of partition functions and whose numerical determination is usually challenging. We develop an efficient method for their computation and apply it to the study of dual superconductivity in 4d compact U(1) gauge theory.Comment: 5 pages, 6 figures. Final revised version published in PR

Chiral transition in a magnetic field and at finite baryon density

We consider the quark-meson model with two quark flavors in a constant external magnetic field $B$ at finite temperature $T$ and finite baryon chemical potential $\mu_B$. We calculate the full renormalized effective potential to one-loop order in perturbation theory. We study the system in the large-$N_c$ limit, where we treat the bosonic modes at tree level. It is shown that the system exhibits dynamical chiral symmetry breaking, i. e. that an arbitrarily weak magnetic field breaks chiral symmetry dynamically, in agreement with earlier calculations using the NJL model. We study the influence on the phase transition of the fermionic vacuum fluctuations. For strong magnetic fields, $|qB|\sim5m_{\pi}^2$ and in the chiral limit, the transition is first order in the entire $\mu_B-T$ plane if vacuum fluctuations are not included and second order if they are included. At the physical point, the transition is a crossover for $\mu_B=0$ with and without vacuum fluctuations.Comment: 11 pages. 5figs. V2: fixed a few typos and added refs. Submitted to PRD. V3: Added refs and substantial revision of tex