The quark-antiquark potential at finite temperature and the dimension two gluon condensate

A recently proposed phenomenological model, which includes non perturbative effects from dimension two gluon condensates, is applied to analyze the available lattice data for the heavy quark free energy in the deconfined phase of quenched QCD. For large $q\bar{q}$ separations we recover previous results for the Polyakov loop, exhibiting unequivocal condensate contributions. For the $q\bar{q}$ potential at finite temperature and finite separation we find that a good overall description of the lattice data can be achieved once the condensate is properly accounted for. In addition, the model predicts a duality between the zero temperature potential as a function of the $q\bar{q}$ separation, on the one hand, and the quark selfenergy as a function of the temperature, on the other, which turns out to be satisfied to a high degree by the lattice data.Comment: 9 pages, 5 figure

Dimension 2 condensates and Polyakov Chiral Quark Models

We address a possible relation between the expectation value of the Polyakov loop in pure gluodynamics and full QCD based on Polyakov Chiral Quark Models where constituent quarks and the Polyakov loop are coupled in a minimal way. To this end we use a center symmetry breaking Gaussian model for the Polyakov loop distribution which accurately reproduces gluodynamics data above the phase transition in terms of dimension 2 gluon condensate. The role played by the quantum and local nature of the Polyakov loop is emphasized.Comment: 3 pages, 1 figure. Talk given at the IVth International Conference on Quarks an Nuclear Physics, Madrid, June 5th-10th 200

Polyakov loop in chiral quark models at finite temperature

We describe how the inclusion of the gluonic Polyakov loop incorporates large gauge invariance and drastically modifies finite temperature calculations in chiral quark models after color neutral states are singled out. This generates an effective theory of quarks and Polyakov loops as basic degrees of freedom. We find a strong suppression of finite temperature effects in hadronic observables triggered by approximate triality conservation (Polyakov cooling), so that while the center symmetry breaking is exponentially small with the constituent quark mass, chiral symmetry restoration is exponentially small with the pion mass. To illustrate the point we compute some low energy observables at finite temperature and show that the finite temperature corrections to the low energy coefficients are $N_c$ suppressed due to color average of the Polyakov loop. Our analysis also shows how the phenomenology of chiral quark models at finite temperature can be made compatible with the expectations of chiral perturbation theory. The implications for the simultaneous center symmetry breaking-chiral symmetry restoration phase transition are also discussed.Comment: 24 pages, 8 ps figures. Figure and appendix added. To appear in Physical Review

The Polyakov loop and the hadron resonance gas model

The Polyakov loop has been used repeatedly as an order parameter in the deconfinement phase transition in QCD. We argue that, in the confined phase, its expectation value can be represented in terms of hadronic states, similarly to the hadron resonance gas model for the pressure. Specifically, L(T) \approx 1/2\sum_\alpha g_\alpha \,e^(-\Delta_\alpha/T), where g_\alpha are the degeneracies and \Delta_\alpha are the masses of hadrons with exactly one heavy quark (the mass of the heavy quark itself being subtracted). We show that this approximate sum rule gives a fair description of available lattice data with N_f=2+1 for temperatures in the range 150MeV<T<190MeV with conventional meson and baryon states from two different models. For temperatures below 150MeV different lattice results disagree. One set of data can be described if exotic hadrons are present in the QCD spectrum while other sets do not require such states.Comment: 5 pages, 4 figures. Error in normalization corrected. Excited states included. Substantially revise

Chiral Lagrangian at finite temperature from the Polyakov-Chiral Quark Model

We analyze the consequences of the inclusion of the gluonic Polyakov loop in chiral quark models at finite temperature. Specifically, the low-energy effective chiral Lagrangian from two such quark models is computed. The tree level vacuum energy density, quark condensate, pion decay constant and Gasser-Leutwyler coefficients are found to acquire a temperature dependence. This dependence is, however, exponentially small for temperatures below the mass gap in the full unquenched calculation. The introduction of the Polyakov loop and its quantum fluctuations is essential to achieve this result and also the correct large $N_c$ counting for the thermal corrections. We find that new coefficients are introduced at ${\cal O}(p^4)$ to account for the Lorentz breaking at finite temperature. As a byproduct, we obtain the effective Lagrangian which describes the coupling of the Polyakov loop to the Goldstone bosons.Comment: 16 pages, no figure

Correlations between perturbation theory and power corrections in QCD at zero and finite temperature

The duality between QCD perturbative series and power corrections recently conjectured by Narison and Zakharov is analyzed. We propose to study correlations between both contributions as diagnostics tool. A very strong correlation between perturbative and non perturbative contributions is observed for several observables at zero and at finite temperature supporting the validity of the dual description.Comment: 7 pages, 5 figures, 7 table

Gender-based violence against women with visual and physical disabilities

Violencia de género en mujeres con discapacidad física y visual. Antecedentes: investigaciones realizadas en distintos países señalan que las mujeres con discapacidad constituyen un grupo de mayor vulnerabilidad para sufrir violencia de género que las mujeres sin discapacidad. Método:un total de 96 mujeres adultas, 45 de ellas con discapacidad visual y 51 con discapacidad física, fueron entrevistadas para conocer la prevalencia de la violencia en este colectivo y su posible relación con factores socioeconómicos, sociodemográficos y relacionados con la discapacidad. Asimismo se analizaron las consecuencias que la violencia provoca en la salud y bienestar psicológico de las mujeres. Resultados: los resultados mostraron una mayor prevalencia de la violencia en esta muestra que el conocido para la población general de mujeres en España. Igualmente, aquellas que habían sido víctimas de violencia mostraron una peor situación económica, mayores niveles de dependencia física y mayores cargas familiares que las que no lo habían sido. Además, la violencia se asoció con peores niveles de bienestar emocional, salud psicológica, autoestima y apoyo social percibido en las mujeres entrevistadas, más allá de los atribuibles a su propia condición de discapacidad. Conclusiones: estos resultados se discutirán a la luz de algunos modelos que relacionan discapacidad y violencia de género

Sexist Attitudes in Online Video Gaming: Development and Validation of the Sexism Against Women Gamers Scale (SAWGS) in Spanish and English

Sexism is an increasingly prevalent problem in the gaming community. However, until now, assessment instruments focused on the construct “sexism against women gamers” are lacking. We present an 8-item self-report scale: Sexism Against Women Gamers Scale (SAWGS). We studied the reliability and validity of the scores of Spanish and English versions across five independent samples (N = 2,437), with participants from Spain and the United States. Scores on both versions demonstrated high reliability, while exploratory and confirmatory factor analyses supported their unidimensional structure. The analysis established configural, metric, and scalar invariance across gender. SAWGS was invariant at the configural level across countries. SAWGS scores were independent of social desirability, positively correlated with myths about intimate-partner violence against women, sexism, and social dominance orientation, and correlated negatively with feminism. Using two fictitious scenarios of sexism in online gaming, we found that gamers with higher scores on SAWGS showed a greater tendency to downplay a sexist incident and proposed a less severe punishment for toxic gamers. The SAWGS explained additional variance on responses to scenarios beyond that explained by other measures. The detection of sexism should make it possible to develop programs for its eradication and avoid negative consequences for women gamers

Numerical taxonomy of moderately halophilic Gram-negative bacteria from hypersaline soils

A total of 132 moderately halophilic bacteria were isolated from hypersaline soils with a C1- content between 2-36 and 12.72% (w/v) located near Alicante (S.E. Spain) and examined for 98 phenotypic characteristics including their response to cytological, physiological, biochemical and nutritional tests. They were submitted to a numerical analysis together with six reference strains using both simple matching (SsM)a nd Jaccard (S,) coefficients, and cluster analysis was carried out by the unweighted pair group method of association (UPGMA), single linkage and complete linkage. With the S, coefficient and UPGMA clustering, eight phenons were obtained at the 65% similarity level. From each phenon representative strains were chosen for the determination of DNA base composition and for electron microscopy. Bacteria belonging to phenons D, E, and F were assigned to the genus Alcaligenes. Phenon G included 27 strains assigned to Acinetobacter, but the high G + C composition (58.9 mol%) of a representative strain of this phenon suggests that it may represent a new taxon. Phenons A, B, and C were designated Flavobacterium and phenon H was Pseudomonas. The bacteria found in these environments are not related to those from hypersaline waters or normal soils