9,513 research outputs found
in the complex two Higgs doublet model
The latest LHC data confirmed the existence of a Higgs-like particle and made
interesting measurements on its decays into , , , , and . It is expected that a decay into might be measured at the next LHC round, for which there already exists
an upper bound. The Higgs-like particle could be a mixture of scalar with a
relatively large component of pseudoscalar. We compute the decay of such a
mixed state into , and we study its properties in the context of the
complex two Higgs doublet model, analysing the effect of the current
measurements on the four versions of this model. We show that a measurement of
the rate at a level consistent with the SM can be used
to place interesting constraints on the pseudoscalar component. We also comment
on the issue of a wrong sign Yukawa coupling for the bottom in Type II models.Comment: 31 pages, 15 figure
A reappraisal of the wrong-sign coupling and the study of
It has been pointed out recently that current experiments still allow for a
two Higgs doublet model where the coupling () is
negative; a sign opposite to that of the Standard Model. Due to the importance
of delayed decoupling in the coupling, improved measurements will have a strong impact on this issue. For the
same reason, measurements or even bounds on are
potentially interesting. In this article, we revisit this problem, highlighting
the crucial importance of , which can be understood with
simple arguments. We show that the impacts on models of both and are very sensitive to
input values for the gluon fusion production mechanism; in contrast, and are not. We also
inquire if the search for and its interplay with will impact the sign of the coupling.
Finally, we study these issues in the context of the Flipped two Higgs doublet
model.Comment: 13 pages, pdf figure
Large pseudoscalar Yukawa couplings in the complex 2HDM
We start by presenting the current status of a complex flavour conserving
two-Higgs doublet model. We will focus on some very interesting scenarios where
unexpectedly the light Higgs couplings to leptons and to b-quarks can have a
large pseudoscalar component with a vanishing scalar component. Predictions for
the allowed parameter space at end of the next run with a total collected
luminosity of and are also discussed. These
scenarios are not excluded by present data and most probably will survive the
next LHC run. However, a measurement of the mixing angle , between
the scalar and pseudoscalar component of the 125 GeV Higgs, in the decay will be able to probe many of these scenarios, even with low
luminosity. Similarly, a measurement of in the vertex
could help to constrain the low region in the Type I model.Comment: 21 pages, 10 figure
CP violation in 2HDM and EFT: the ZZZ vertex
We study the CP violating ZZZ vertex in the two-Higgs doublet model, which is
a probe of a Jarlskog-type invariant in the extended Higgs sector. The form
factor is evaluated at one loop in a general gauge and its
magnitude is estimated in the realistic parameter space. Then we turn to the
decoupling limit of the two-Higgs doublet model, where the extra scalars are
heavy and the physics can be described by the Standard Model supplemented by
higher-dimensional operators. The leading operator contributing to at
one loop is identified. The CP violating ZZZ vertex is not generated in the
effective theory by dimension-8 operators, but instead arises only at the
dimension-12 level, which implies an additional suppression by powers of the
heavy Higgs mass scale.Comment: 21 pages; v2: added references and comments, appendix A on method of
regions, and appendix B on derivation of CP-violating effective Lagrangian.
Corrected discussion of dimension-12 operators contributing to ZZZ vertex.
Final JHEP versio
As novas tecnologias de informação no ensino da biologia: um estudo sobre fotossíntese com alunos do 10º ano de escolaridade
Ao longo das duas últimas décadas, investigações desenvolvidas no domínio do ensino da Biologia revelaram que muitos alunos possuíam concepções alternativas. Este facto conduziu ao incremento de uma linha de investigação centrada em estratégias de ensino que pudessem facilitar o desenvolvimento/ reestruturação dessas concepções. Algumas dessas estratégias incluem o recurso às Tecnologias de Informação, nomeadamente, ao Sistema de Aquisição e Tratamento de Dados (SATD), uma vez que este equipamento, ao permitir reduzir o tempo gasto no tratamento de dados, disponibiliza um maior período de tempo para os alunos preverem resultados, reflectirem e discutirem resultados obtidos, bem como compararem resultados discrepantes. Tendo como referência estas investigações, realizou-se um estudo, no tema "Fotossíntese", que incluiu 41 alunos do 10.0 ano de escolaridade, distribuídos por duas turmas - uma experimental e outra de controlo. As duas desenvolveram actividades laboratoriais, com recurso, respectivamente, ao SATD (turma experimental) e a equipamento tradicional (turma de controlo). A análise de resultados mostrou que os alunos da primeira revelaram, relativamente aos alunos da segunda, uma evolução conceptual mais extensa no tópico "Fotossíntese". Estes resultados parecem indicar que o SATD constitui um factor facilitador da aprendizagem dos alunos.During the last two decades, research studies carried out within the domain of biology educacion have shown that many students' hold alternative conceptions. This fact led to the development of another area of research that focuses on teaching strategies aiming at developing/restructuring those conceptions. Some of those strategies are based on information technology, namely on datalloging. Several researchers have argued that datalogging reduces the time usually spent with data handling and therefore releases a longer time interval (that can be used) for prevision of results, reflection upon both discussion of data collected and discrepant results. In order to evaluate the efficacy of datalogging to promote students' conceptual development a research study focusing on photosynthesis was canied out. The research was undertaken with 41 tenth graders that were allocated to a control class and to an experimental class. Both classes carried out the sarne laboratory activities but the former used traditional lab equipment whilst the latter utilised datalogging. The analysis of the results shows that students in the experimental class experienced a deeper conceptual change than their control class counterparts. These results seem to indicare that datalogging facilitares students’ learning on photosynthesis.Des recherches dans le domaine de l'enseignement de la Biologie ont révélé que bien des d'éleves possedent des conceptions alternatives. Ce fait a conduit au développement d'une autre ligne de recherche centrée sur des sLratégies d'enseignement qui facilitem le développement/restructuration de ces conceptions. Certaines de ces stratégies incluent des Technologies de l'Information, notamment "l'expérimentation assistée par ordinateur" (ExAO), vu qu'il permet de réduire le temps gaspillé avec le traitement des données, offre plus de temps pour que les éleves prévoient des résultats, réfléchissent sur les résultats obtenus et en discutent, et qu'ils comparent les résultats discordants. Ayant pour référence ces lignes de recherche, on a réalisé une étude, sur la photosynthese, qui a indu 41 éleves de la lüe année de scolarité, distribués dans deux classes - une expérimentale et une autre de contrôle. Les deux classes ont développé des activités de laboratoire en recourant respectivement au ExAO et à un équipement traditionnel. L'analyse des résultats a montré que les éleves de la classe expérimentale ont révélé, relativement aux éleves de la classe de contôle, une évolution conceptuelle plus large dans la photosynthese. Ces résultats semblent indiquer que le ExAO constitue un facteur qui facilite l'apprentissage des éleves
The role of environmental concern and technology show-off on electric vehicles adoption: the case of Macau
Purpose: Research on battery electric vehicles (BEVs) has typically considered environmental concern a key determinant of behavioral intention that leads individuals to prefer electric vehicles. This paper challenges this assumption and argues that technology frameworks may require new variables to capture consumers' preferences. A UTAUT2-based study has been developed to assess the role of environmental concern in the BEVs context and put forward the technology show-off (TS) concept to explain the technology's acceptance. Design/methodology/approach: A quantitative and cross-sectional look at behavioral intention is adopted. The study uses structural equation modeling to analyze a sample of 236 Macau residents to determine the relevance of the factors behind the choice to adopt BEVs. Findings: The findings indicate that environmental concern and price may be relevant to explain behavioral intention to adopt the BEVs technology. Furthermore, the UTAUT2 framework seems to benefit from adding new variables, with TS playing a pertinent role in explaining technology acceptance. Social implications: The findings show that environmental concern fails to build an argument for the shift to full electric mobility and promote the desired behavioral change toward adopting BEVs. Herein lies the necessity to consider new variables that can better describe the characteristics of modern society.Originality/value: This paper proposes the TS construct, combining visibility and trialability as significant determinants of behavioral intention to use technology. The study also stresses the need to reconsider the role of environmental concerns' impact on consumer decision-making.info:eu-repo/semantics/acceptedVersio
Does cultural background influence the dissemination and severity of the COVID-19 pandemic?
The COVID-19 pandemic has spread throughout the globe affecting countries worldwide. However, several differences have been observed in the number of daily new cases, the COVID-19 reproduction rate, and the severity of the disease in different countries. Previous studies have mostly highlighted government restriction policies to mitigate the pandemic effects as reasons for such differences. This study focuses on 101 countries and proposes that each country’s cultural background is also accountable for such differences. We considered the six Hofstede’s cultural dimensions (power distance, individualism, masculinity, uncertainty avoidance, long term orientation, and indulgence) and statistically analyzed their correlation with several COVID-19 impact metrics in comparison to several restriction policies. Our results support our claim that national culture influences both acceptance and subsequent adoption of restriction policies and the implementation by each government of those policies. We highlight that the attitudes towards and trust in political institutions, policies and governance is influenced by the cultural background, which is reflected in the pandemic numbers. As a main takeaway from this study, we conclude that data-driven models which aim at predicting the pandemic impact evolution at a global scale should also include variables that reflect the cultural background of each nation.info:eu-repo/semantics/publishedVersio
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