The Boer-Mulders effect in unpolarized SIDIS: an analysis of the COMPASS and HERMES data on the cos⁡2ϕ\cos 2 \phi asymmetry

We present a phenomenological analysis of the $\cos 2 \phi$ asymmetry recently measured by the COMPASS and HERMES collaborations in unpolarized semi-inclusive deep inelastic scattering. In the kinematical regimes explored by these experiments the asymmetry arises from transverse-spin and intrinsic transverse-momentum effects. We consider the leading-twist contribution, related to the so-called Boer-Mulders transverse-polarization distribution $h_1^{\perp}(x, k_T^2)$, and the twist-4 Cahn contribution, involving unpolarized transverse-momentum distribution functions. We show that a reasonably good fit of the data is achieved with a Boer-Mulders function consistent with the main theoretical expectations. Our conclusion is that the COMPASS and HERMES measurements represent the first experimental evidence of the Boer-Mulders effect in SIDIS.Comment: 11 pages, 7 figures, published version in PR

Azimuthal asymmetries in unpolarized Drell-Yan processes and the Boer-Mulders distributions of antiquarks

Using a previous extraction of the quark Boer-Mulders distributions from semiinclusive deep inelastic scattering data, we fit the unpolarized Drell-Yan data on the $\cos 2 \phi$ asymmetry, determining the antiquark Boer-Mulders distributions. A good agreement with the data is found in the region of low $q_T$, where the transverse-momentum factorization approach applies.Comment: 7 pages, 3 figure

Pandemetrics: systematically assessing, monitoring, and controlling the evolution of a pandemic

The still ongoing pandemic of SARS-CoV-2 virus and COVID-19 disease, affecting the population worldwide, has demonstrated the need of more accurate methodologies for assessing, monitoring, and controlling an outbreak of such devastating proportions. Authoritative attempts have been made in traditional fields of medicine (epidemiology, virology, infectiology) to address these shortcomings, mainly by relying on mathematical and statistical modeling. However, here, we propose approaching the methodological work from a different, and to some extent alternative, standpoint. Applied systematically, the concepts and tools of statistical engineering and quality management, developed not only in healthcare settings, but also in other scientific contexts, can be very useful in assessing, monitoring, and controlling pandemic events. We propose a methodology based on a set of tools and techniques, formulas, graphs, and tables to support the decision-making concerning the management of a pandemic like COVID-19. This methodological body is hereby named Pandemetrics. This name intends to emphasize the peculiarity of our approach to measuring, and graphically presenting the unique context of the COVID-19 pandemic

Manager’s and citizen’s perspective of positive and negative risks for small probabilities

So far „risk‟ has been mostly defined as the expected value of a loss, mathematically PL, being P the probability of an adverse event and L the loss incurred as a consequence of the event. The so called risk matrix is based on this definition. Also for favorable events one usually refers to the expected gain PG, being G the gain incurred as a consequence of the positive event. These “measures” are generally violated in practice. The case of insurances (on the side of losses, negative risk) and the case of lotteries (on the side of gains, positive risk) are the most obvious. In these cases a single person is available to pay a higher price than that stated by the mathematical expected value, according to (more or less theoretically justified) measures. The higher the risk, the higher the unfair accepted price. The definition of risk as expected value is justified in a long term “manager‟s” perspective, in which it is conceivable to distribute the effects of an adverse event on a large number of subjects or a large number of recurrences. In other words, this definition is mostly justified on frequentist terms. Moreover, according to this definition, in two extreme situations (high-probability/low-consequence and low-probability/high-consequence), the estimated risk is low. This logic is against the principles of sustainability and continuous improvement, which should impose instead both a continuous search for lower probabilities of adverse events (higher and higher reliability) and a continuous search for lower impact of adverse events (in accordance with the fail-safe principle). In this work a different definition of risk is proposed, which stems from the idea of safeguard: (1Risk)=(1P)(1L). According to this definition, the risk levels can be considered low only when both the probability of the adverse event and the loss are small. Such perspective, in which the calculation of safeguard is privileged to the calculation of risk, would possibly avoid exposing the Society to catastrophic consequences, sometimes due to wrong or oversimplified use of probabilistic models. Therefore, it can be seen as the citizen‟s perspective to the definition of risk

Rethinking the risk matrix

So far risk has been mostly defined as the expected value of a loss, mathematically PL (being P the probability of an adverse event and L the loss incurred as a consequence of the adverse event). The so called risk matrix follows from such definition. This definition of risk is justified in a long term “managerial” perspective, in which it is conceivable to distribute the effects of an adverse event on a large number of subjects or a large number of recurrences. In other words, this definition is mostly justified on frequentist terms. Moreover, according to this definition, in two extreme situations (high-probability/low-consequence and low-probability/high-consequence), the estimated risk is low. This logic is against the principles of sustainability and continuous improvement, which should impose instead both a continuous search for lower probabilities of adverse events (higher and higher reliability) and a continuous search for lower impact of adverse events (in accordance with the fail-safe principle). In this work a different definition of risk is proposed, which stems from the idea of safeguard: (1Risk)=(1P)(1L). According to this definition, the risk levels can be considered low only when both the probability of the adverse event and the loss are small. Such perspective, in which the calculation of safeguard is privileged to the calculation of risk, would possibly avoid exposing the Society to catastrophic consequences, sometimes due to wrong or oversimplified use of probabilistic models. Therefore, it can be seen as the citizen’s perspective to the definition of risk

Enhanced TESF methodology for course excellence

The need to achieve the excellence in services provided by a University has been object of study and research for several decades. Often, the focus is not only on the education service, but on several satellite services provided by a university. This article focuses on teaching, considered as a central service, believing (the authors) that the improvement actions of an academic institution should always start from this service. The work proposes the implementation of a tool able to measure student perceptions on certain selected aspects of the course. This tool is part of the Teaching Experiment and Student Feedback (TESF) methodology previously developed by the authors. Here, the steps to build a student satisfaction coefficient are fully described and data collected in one course edition are analysed. The TESF methodology responds to the evidence-based management principle for direct and simple use by a statistics teacher. It allows making decisions and organizing practical aspects driven by data collected directly from students, and scientifically analysed

Feeling so Hood. Rap, lifestyles and the neighbourhood imaginary in Tunisia

The article examines the role of rap in reimagining the social structure in Tunisia after its 2010/2011 revolution. Before the revolution, the Ben Ali regime imposed a narrative of Tunisian society as mainly middle class; beneath this narrative, the Tunisian folklore hosted multiple markers of social distinction that classified people through their perceived lifestyles: residence, language habits, consumption patterns, religious attitudes. Disadvantaged neighbourhoods were obliterated by the official narrative and condemned to social spite by the unofficial ones. After the revolution, the success of rap came to ‘represent’ those quarters and the youth that inhabited them: rappers sang the hoods by criticizing their hard conditions and, at the same time, glorifying the hoods themselves. The vagueness of the social narratives in the country allowed rap musicians to manipulate both the image of the poor neighbourhoods and the idioms of social difference circulating in Tunisia: through this manipulation, they provided a new dignity to the most marginalized sectors of Tunisian society. At the same time, by representing the hoods, rappers could claim social capital and credibility as the ‘true’ narrators of the new Tunisia. But the reimagination of social narratives was not enough to improve the life conditions of dispossessed youth

Metal, Rap, and Electro in post-revolutionary Tunisia. A Fragile Underground

Metal, Rap, and Electro in post-revolutionary Tunisia is a trip into the music scenes of Tunisia after the Arab Springs. Based on extensive field research, it explores the social life of heavy metal, rap, and electronic music in a North African country whose mass revolution of 2010/2011 led the way to a troubled and yet unique democracy. How is it to be part of a music scene in a place affected by severe inequality? How do the many conflictual souls of Tunisian Islam shape local metal, rap, and electro? What are the social and cultural stakes of music in a nation constantly represented as a bridge between Europe and the Middle East? How do music scenes articulate the complex political scenario that followed the Tunisian revolution of 2011? The book answers these questions by offering new theoretical reflections on youth cultures and popular music in a global perspective, and thus pushing the debate on “post-subcultures” and music scenes forward. At the same time, it offers a dense sociological analysis of youth and music in a country whose society, culture, religion, and politics are stakes in a historical transformation

Electronic Dunes and Downtown Vibes. The Social Construction of an Underground Electro Scene in Tunisia

The paper explores the making of an electronic music scene in Tunisia, before and after the country’s 2010/2011 revolution. Such a scene developed in the context of a pre-existing “mainstream” club circuit, which embodied many political and social features of pre-revolutionary Tunisia. The electro scene activists managed to react against such a mainstream, but they were obliged to borrow its infrastructures and thus negotiate with its social characteristics. Different sections of the scene accepted or refused different elements of the perceived mainstream. As a result, they produced different and conflicting understandings of the local “underground”

Evaluation of Tomato Genetic Resources for Response to Water Deficit

Water deficit strongly affects plant yield and quality. However, plants can minimize drought injury by adaptation mechanisms that have evolved to escape harmful conditions. The response to water deprivation is a complex trait controlled by several genes. In order to gain a deeper understanding of drought response mechanisms in tomato, a collection of 27 genotypes was studied under different water deficit conditions. Since developmental stages might be differently influenced by drought, analyses were carried out on young plantlets during fruit setting. The only genotype that showed good performances both as water retention and fruit production was the ecotype Siccagno. All the genotypes were analysed at molecular level with the aim of detecting structural polymorphisms in selected stress-responsive genes. In addition, the expression level of a number of these genes was measured in the genotypes more tolerant to water deficit. Many polymorphisms were detected in six stress-responsive genes, and some could imply significant modifications in the protein structure. Furthermore, the expression analysis by RT-qPCR of three stress-responsive genes allowed arguing that a higher level of expression of the gene erd15 might be related to the better response to water deficit exhibited by Siccagno. Similarly, the lower expression of eight genes in the same genotype analysed through a microarray experiment confirmed the involvement of these stress-related genes in the tomato response to drought. Further investigations are required for a better comprehension of the mechanisms underlying response to water deficit in tomato by exploiting the genetic resource identified as more tolerant. The use of new technologies able to globally analyse structural polymorphism and expression level of genes will succeed to identify crucial genes involved in stress response in the ecotype Siccagno grown under different water regimes