Using single top rapidity to measure V_td, V_ts, V_tb at hadron colliders

Single top production processes are usually regarded as the ones in which V_tb can be directly measured at hadron colliders. We show that the analysis of the single top rapidity distribution in t-channel and tW production can also set direct limits on V_td. At LHC with 10 fb^-1 at 14 TeV the combined limits on V_td may be reduced by almost a factor of two when the top rapidity distribution is used. This also implies that the limits on V_tb can also be reduced by 15%, since both parameters as well as V_ts must be simultaneously obtained from a global fit to data. At Tevatron the explotation of this distribution would require very high statistics.Comment: LaTeX 19 pages, 48 PS figures. A section added with estimations of systematics, LO/NLO comparison and a fast detector simulation. Final version to appear in PR

Constraints on the Wtb vertex from early LHC data

We use the recent measurements of top quark decay asymmetries in ATLAS and the t-channel single top cross section in CMS to set the first combined LHC limits on the Wtb vertex. This combination allows to obtain much better limits than the separate measurements. The resulting constraints are comparable, although still weaker, than the ones obtained using Tevatron data with much more statistics.Comment: RevTeX 4 page

Motivation and perceived motivational climate by adolescents in face-to-face physical education during the COVID-19 pandemic

The COVID-19 pandemic impacted adolescents’ lives, leading to unprecedented changes in their routines, especially in education. Face-to-face physical education (PE) classes during COVID-19 were affected in organization, possibly conditioning students’ participation, motivation and learning. Based on the achievement goal and self-determination theories, the aim of this study was to analyze and compare the motivational indicators of adolescents in face-to-face PE classes during COVID-19, according to gender, educational level and physical activity (PA). A total of 1369 students participated in the study (621 boys and 748 girls; mean age: 14.4 years; SD: 1.74). Data were collected via an online questionnaire and analyzed using MANCOVAs adjusted for age, pre- and post-COVID-19 PA, socioeconomic status and BMI (Z-score). Differences in achievement goals, motivational climate and motivational regulation levels were found in different groups by gender, PA and educational level, favoring older and more active participants. A more positive motivational profile was found for girls in general and, specifically, for active boys, regarding more self-determined motivations and mastery goal orientations. Overall, this study’s findings suggest that the restrictions related to face-to-face PE classes during the COVID-19 pandemic had a negative impact on students’ motivation.info:eu-repo/semantics/publishedVersio

A Frustrated 3-Dimensional Antiferromagnet: Stacked J1−J2J_{1}-J_{2} Layers

We study a frustrated 3D antiferromagnet of stacked $J_1 - J_2$ layers. The intermediate 'quantum spin liquid' phase, present in the 2D case, narrows with increasing interlayer coupling and vanishes at a triple point. Beyond this there is a direct first-order transition from N{\' e}el to columnar order. Possible applications to real materials are discussed.Comment: 11 pages,7 figure

The synergy factor: a statistic to measure interactions in complex diseases

<p>Abstract</p> <p>Background</p> <p>One challenge in understanding complex diseases lies in revealing the interactions between susceptibility factors, such as genetic polymorphisms and environmental exposures. There is thus a need to examine such interactions explicitly. A corollary is the need for an accessible method of measuring both the size and the significance of interactions, which can be used by non-statisticians and with summarised, e.g. published data. The lack of such a readily available method has contributed to confusion in the field.</p> <p>Findings</p> <p>The synergy factor (<it>SF</it>) allows assessment of binary interactions in case-control studies. In this paper we describe its properties and its novel characteristics, e.g. in calculating the power to detect a synergistic effect and in its application to meta-analyses. We illustrate these functions with real examples in Alzheimer's disease, e.g. a meta-analysis of the potential interaction between a <it>BACE1 </it>polymorphism and <it>APOE</it>4: <it>SF </it>= 2.5, 95% confidence interval: 1.5–4.2; <it>p </it>= 0.0001.</p> <p>Conclusion</p> <p>Synergy factors are easy to use and clear to interpret. Calculations may be performed through the Excel programmes provided within this article. Unlike logistic regression analysis, the method can be applied to datasets of any size, however small. It can be applied to primary or summarised data, e.g. published data. It can be used with any type of susceptibility factor, provided the data are dichotomised. Novel features include power estimation and meta-analysis.</p

Social Cognitive Theory and Health Care: Analysis and Evaluation

Social Cognitive Theory explains how different personal, environmental and cognitive factors influence human behavior and it has been an important source of knowledge in the social and health sciences. It has been employed in research and practice in nursing, the science of caring. However, no critical analysis has been conducted to show the impact of Social Cognitive Theory in nursing. This article aims to conduct an analysis and evaluation of Social Cognitive Theory using the Fawcett and DeSanto-Madeya methodological framework and a systematic search of the literature. Social Cognitive Theory showed that even though is a non-disciplinary theory of health sciences, the clarity and simplicity of its content facilitates its use in understanding and addressing different phenomena of caring, the creation of middle-range theories and in professional education. The contribution of Social Cognitive Theory in nursing science has focused mainly on two aspects: firstly, on improving disciplinary knowledge with the practical context of health caring by understanding human behavior and its integration in interventions for the promotion, prevention and treatment of health, and secondly, on nursing professionals’ education, highlighting the relevance of the interdisciplinary nature of knowledge

New limits on anomalous contributions to the Wtb vertex

The authors would like to thank the Center for Theoretical Physics of the Physics Department at the New York City College of Technology, for providing computing power from their High-Performance Computing Cluster. The work of M.C.N. Fiolhais was supported by FCT Grant No. SFRH/BPD/100379/2014. The work of C. M. Pease was partly supported by Macaulay Honors College. The authors would also like to thank Juan Antonio Aguilar-Saavedra and Nuno F. Castro for a long time collaboration.The latest and most precise top quark measurements at the LHC and Tevatron are used to establish new limits on the Wtb vertex. Recent results on the measurements of the W-boson helicity fractions and single top quark production cross section are combined in order to establish new limits at 95% CL (confidence level). The allowed regions for these limits are presented, for the first time, in three-dimensional graphics, for both real and imaginary components of the different anomalous couplings, providing a new perspective on the impact of the combination of different physics observables. These results are also combined with the prospected future measurement of the single top quark production cross section and W-boson helicity fractions at the LHC.The authors would like to thank the Center for Theoretical Physics of the Physics Department at the New York City College of Technology, for providing computing power from their High-Performance Computing Cluster. The work of M.C.N. Fiolhais was supported by FCT Grant No. SFRH/BPD/100379/2014. TheworkofC.M.PeasewaspartlysupportedbyMacaulay Honors College. The authors would also like to thank Juan Antonio Aguilar-Saavedra and Nuno F. Castro for a long time collaboration

MEtop – a top FCNC event generator

In this work we present a new Monte Carlo generator for Direct top and Single top production via flavour-changing neutral currents (FCNC). This new tool calculates the cross section and generates events with Next-to-Leading order precision for the Direct top process and Leading-Order precision for all other FCNC single top processes. A set of independent dimension six FCNC operators has been implemented - including four-fermion operators - where at least one top-quark is present in the interaction.This work is partially supported by the Portuguese Fundacao para a Ciencia e a Tecnologia (FCT) under contracts CERN/FP/123619/2011 and PTDC/FIS/117951/2010. RS is also partially supported by an FP7 Reintegration Grant, number PERG08-GA-2010-277025 and by PEst-OE/FIS/UI0618/2011. RC is funded by FCT through the grant SFRH/BPD/45198/2008