Chiral effective field theories of the strong interactions

Effective field theories of the strong interactions based on the approximate chiral symmetry of QCD provide a model-independent approach to low-energy hadron physics. We give a brief introduction to mesonic and baryonic chiral perturbation theory and discuss a number of applications. We also consider the effective field theory including vector and axial-vector mesons.Comment: 22 pages, 9 figures, proceedings of "Many-Body Structure of Strongly Interacting Systems", Mainz, Germany, Feb. 23-25 201

Normative and validation data of an articulation test for Italian-speaking children

Objectives: As a standardized instrument to assess speech sound development in Italian-speaking children is currently lacking, norms used to diagnose speech sound disorders (SSD) are mainly based on studies including English-speaking participants. This application may result in misidentification of SSD due to linguistic differences. The aims of the study were to establish normative data on speech sound development of Italian-speaking children and to evaluate psychometric properties of Rossi's articulation test, the picture-naming test selected to assess speech sound development. Methods: A cross-sectional study including 694 normally-developing Italian-speaking children aged from 3 to 7 years was conducted. Children were administered Rossi's articulation test, and percentages of speech sound correct production were calculated. To evaluate inter-rater reliability of the test, audio-recordings of 50 children were scored by an additional examiner. The same rater scored the audio-recordings of 50 children twice with an interval of at least 1 week. To evaluate test-retest reliability, 144 participants were re-tested after 1-3 weeks by the same assessor. Scores were compared through Intraclass Correlation Coefficient (ICC). To assess construct validity, the developmental progression of total scores across age groups was verified by the estimation of the reference range for the test, using a regression procedure. Results: Almost all Italian children in the sample produced vowels and approximants correctly. Singleton consonants were acquired before consonant clusters. Ages of acquisition of each consonant were presented: plosives and nasals were early mastered by Italian children, while dental affricates, alveolar fricatives and the palatal lateral were the latest acquired segments. All ICCs were superior to 0.9 (reliability). A statistically significant improvement in test score with age was found (construct validity). Conclusions: The paper provides normative data for speech sound development of Italian-speaking children; preliminary psychometric analysis of Rossi's articulation test revealed satisfactory reliability and construct validity. Clinicians are recommended to use Rossi's articulation test to assess speech sound development in Italian children

The Relationship between Socioeconomic Status and Narrative Abilities in a Group of Italian Normally Developing Children

OBJECTIVE: Only limited and conflicting information is available regarding the relationship between socioeconomic status (SES) and narrative abilities. Besides, the role fathers' SES plays in the development of their children's narrative abilities has never been investigated. The aim of this study was to analyze the relationship between fathers' and mothers' SES and narrative abilities of their children assessed with the Italian version of the Bus Story Test (I-BST). SUBJECTS AND METHODS: A total of 505 normally developing Italian children were enrolled in the study. Information regarding parents' educational level and employment was collected for each child. Narrative abilities were evaluated using the I-BST. The relationships between parents' employment, educational level, and I-BST scores were analyzed by univariate and multivariate regression analysis. RESULTS: In univariate analysis, both fathers' and mothers' education and employment were associated with most I-BST subscale scores, especially when higher educational and employment levels were contrasted with the lowest educational and employment levels. In multiple regression analysis, significant associations were found only between the fathers' working status and educational level and I-BST subscale scores. CONCLUSIONS: Parental education and employment might impact narrative abilities of children. When both fathers' and mothers' SES variables are considered together, only fathers' education and working status seemed to be associated with I-BST scores

Instruments evaluating the clinical findings of laryngopharyngeal reflux: A systematic review

Objectives: To identify the instruments for evaluating the clinical findings (ICFs) of laryngopharyngeal reflux (LPR) designed for use with regard to diagnosis and treatment effectiveness. Methods: The PubMed, Scopus, and Cochrane databases were used to search for subject headings following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) recommendations. Three investigators retrieved relevant studies published between 1990 and 2018 describing the evolution of laryngopharyngeal findings throughout LPR treatment. Issues of clinical relevance, that is, LPR diagnosis, treatments, and signs assessed for diagnosis or as therapeutic outcomes, were assessed. The investigators also evaluated the psychometric properties (conceptual model, content validity, consistency, reliability, concordance, convergent validity, known-groups validity, responsiveness to change, and interpretability) of the ICF. The risk of bias was assessed with the tool of the Clarity Group and Evidence Partners. Results: The search identified 1,227 publications with a total of 4,735 LPR patients; of these studies, 53 met the inclusion criteria. Of these 53 studies, we identified 10 unvalidated and six validated ICFs. None of the validated ICFs included all the psychometric properties. The main identified deficiencies related to ICF psychometric validation included variable construct validity, disparate and uncertain reliabilities, and a lack of interpretability. The lack of consideration of certain LPR laryngeal and extralaryngeal signs is the main weakness of ICFs, biasing content, and construct validities. Conclusion: The low specificity of LPR signs, the lack of consideration of many findings, and the absence of a gold standard for diagnosis constitute barriers to the further validation of these ICFs. Additional studies are needed to develop complete and reliable ICFs. Laryngoscope, 2018

On Parity-Violating Three-Nucleon Interactions and the Predictive Power of Few-Nucleon EFT at Very Low Energies

We address the typical strengths of hadronic parity-violating three-nucleon interactions in "pion-less" Effective Field Theory in the nucleon-deuteron (iso-doublet) system. By analysing the superficial degree of divergence of loop diagrams, we conclude that no such interactions are needed at leading order. The only two linearly independent parity-violating three-nucleon structures with one derivative mix two-S and two-P-half waves with iso-spin transitions Delta I = 0 or 1. Due to their structure, they cannot absorb any divergence ostensibly appearing at next-to-leading order. This observation is based on the approximate realisation of Wigner's combined SU(4) spin-isospin symmetry in the two-nucleon system, even when effective-range corrections are included. Parity-violating three-nucleon interactions thus only appear beyond next-to-leading order. This guarantees renormalisability of the theory to that order without introducing new, unknown coupling constants and allows the direct extraction of parity-violating two-nucleon interactions from three-nucleon experiments.Comment: 20 pages LaTeX2e, including 9 figures as .eps file embedded with includegraphicx. Minor modifications and stylistic corrections. Version accepted for publication in Eur. Phys. J.

On chiral corrections to nucleon GPD

Within the pion-nucleon chiral perturbation theory we derive the leading chiral correction to the nucleon GPD at $\xi=0$. We discuss the difficulties of consideration of nonlocal light-cone operators within the theory with a heavy particle and the methods to solve the difficulties. The consideration of the chiral corrections directly for nonlocal operators allows to resolve the ambiguity of the inverse Mellin transformation. In particular, we show that the mixing between axial and vector GPDs are of order $m_\pi^2/M_N^2$, which is two orders of magnitude less that it follows from the Mellin moments calculation.Comment: 17 pages, 1 figure; minor corrections in the tex

Parity-violating neutron spin rotation in hydrogen and deuterium

We calculate the (parity-violating) spin rotation angle of a polarized neutron beam through hydrogen and deuterium targets, using pionless effective field theory up to next-to-leading order. Our result is part of a program to obtain the five leading independent low-energy parameters that characterize hadronic parity-violation from few-body observables in one systematic and consistent framework. The two spin-rotation angles provide independent constraints on these parameters. Using naive dimensional analysis to estimate the typical size of the couplings, we expect the signal for standard target densities to be 10^-7 to 10^-6 rad/m for both hydrogen and deuterium targets. We find no indication that the nd observable is enhanced compared to the np one. All results are properly renormalized. An estimate of the numerical and systematic uncertainties of our calculations indicates excellent convergence. An appendix contains the relevant partial-wave projectors of the three-nucleon system.Comment: 44 pages, 17 figures; minor corrections; to be published in EPJ

Finite volume corrections to the electromagnetic current of the nucleon

We compute corrections to both the isovector anomalous magnetic moment and the isovector electromagnetic current of the nucleon to $O(p^3)$ in the framework of covariant two-flavor Baryon Chiral Perturbation Theory. We then apply these corrections to lattice data for the anomalous magnetic moment from the LHPC, RBC & UKQCD and QCDSF collaborations

Bayesian Methods for Parameter Estimation in Effective Field Theories

We demonstrate and explicate Bayesian methods for fitting the parameters that encode the impact of short-distance physics on observables in effective field theories (EFTs). We use Bayes' theorem together with the principle of maximum entropy to account for the prior information that these parameters should be natural, i.e.O(1) in appropriate units. Marginalization can then be employed to integrate the resulting probability density function (pdf) over the EFT parameters that are not of specific interest in the fit. We also explore marginalization over the order of the EFT calculation, M, and over the variable, R, that encodes the inherent ambiguity in the notion that these parameters are O(1). This results in a very general formula for the pdf of the EFT parameters of interest given a data set, D. We use this formula and the simpler "augmented chi-squared" in a toy problem for which we generate pseudo-data. These Bayesian methods, when used in combination with the "naturalness prior", facilitate reliable extractions of EFT parameters in cases where chi-squared methods are ambiguous at best. We also examine the problem of extracting the nucleon mass in the chiral limit, M_0, and the nucleon sigma term, from pseudo-data on the nucleon mass as a function of the pion mass. We find that Bayesian techniques can provide reliable information on M_0, even if some of the data points used for the extraction lie outside the region of applicability of the EFT.Comment: 36 pages, 4 figures, numerical errors in Sec. IV and V corrected, main conclusions unaffecte

Thermal radiation processes

We discuss the different physical processes that are important to understand the thermal X-ray emission and absorption spectra of the diffuse gas in clusters of galaxies and the warm-hot intergalactic medium. The ionisation balance, line and continuum emission and absorption properties are reviewed and several practical examples are given that illustrate the most important diagnostic features in the X-ray spectra.Comment: 37 pages, 16 figures, accepted for publication in Space Science Reviews, special issue "Clusters of galaxies: beyond the thermal view", Editor J.S. Kaastra, Chapter 9; work done by an international team at the International Space Science Institute (ISSI), Bern, organised by J.S. Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke