The spectrum of static-light baryons in twisted mass lattice QCD

We compute the static-light baryon spectrum with N_f = 2 flavors of sea quarks using Wilson twisted mass lattice QCD. As light valence quarks we consider quarks, which have the same mass as the sea quarks with corresponding pion masses in the range 340 MeV < m_PS < 525 MeV, as well as partially quenched quarks, which have the mass of the physical s quark. We extract masses of states with isospin I = 0, 1/2, 1, with strangeness S = 0, -1, -2, with angular momentum of the light degrees of freedom j = 0, 1 and with parity P = +, -. We present a preliminary extrapolation in the light u/d and an interpolation in the heavy b quark mass to the physical point and compare with available experimental results.Comment: 7 pages, 2 figures, talk given at the XXVIII International Symposium on Lattice Field Theory (Lattice 2010), June 14-19 2010, Villasimius, Ital

Social support in offices : elements, driving factors and their influence on work engagement

The influence of the Professional Dimension of Social Support on work engagement has often been the topic of investigation and is mostly seen as the decisive and only dimension for investigating Social Support in organizations. Despite the known influence of Social Support on Work Engagement, there is only little attention paid to the Personal Dimension of the employee/coworker and employee/superior relationship. This thesis first examines the relationship between “liking” (having a good personal relationship) and “working supportively together “(having a good professional relationship) and afterwards investigates their influence on Work Engagement. Additionally the possible negative influences of too strong personal relationships and the existence of common good practices and work environment attributes in organizations that drive Social Support is investigated. For the Co-worker relationship Work Engagement found the Companionship and Informational Dimension to positively and the Emotional and Instrumental Dimension to negatively affect Work Engagement. For both, the Co-worker and Supervisor relationship, the Personal- and Professional Support levels are highly correlated and too high Supervisor Personal Support that don’t match the employees Power Distance Index negatively effects Work Engagement. Lastly regular team and supervisor meetings, as well as the recognition of good performance and the existence of break out spaces are found to positively affect Social Support levels.A influência da Dimensão Profissional do Apoio Social sobre o engajamento no trabalho tem sido freqüentemente tema de investigação e é sobretudo vista como a dimensão decisiva e única para investigar o Apoio Social nas organizações. Apesar da conhecida influência do Apoio Social ao Trabalho, há pouca atenção prestada à Dimensão Pessoal da relação empregado / colega de trabalho e empregado / superior. Esta tese examina primeiramente a relação entre "gostar" (ter uma boa relação pessoal) e "trabalhar solidariamente em conjunto" (ter uma boa relação profissional) e, posteriormente, investigar sua influência no Trabalho. Além disso, são investigadas as possíveis influências negativas de relacionamentos pessoais muito fortes e a existência de boas práticas comuns e atributos do ambiente de trabalho nas organizações que impulsionam o Apoio Social. Para a relação de colega de trabalho, encontramos a dimensão de companheirismo e informação como positiva e a dimensão emocional e instrumental para afetar negativamente o engajamento no trabalho. Para ambos, o relacionamento de Colaborador e Supervisor, os níveis de Suporte Pessoal e Profissional estão altamente correlacionados e um Suporte Pessoal de Supervisor muito alto que não corresponde ao Índice de Distância de Poder dos funcionários afeta negativamente o Envolvimento no Trabalho. Por fim, as reuniões regulares de equipe e supervisor, bem como o reconhecimento do bom desempenho ea existência de espaços de ruptura, afetam positivamente os níveis de Apoio Social

A Lattice Calculation of Parton Distributions

We present results for the $x$ dependence of the unpolarized, helicity, and transversity isovector quark distributions in the proton using lattice QCD, employing the method of quasi-distributions proposed by Ji in 2013. Compared to a previous calculation by us, the errors are reduced by a factor of about 2.5. Moreover, we present our first results for the polarized sector of the proton, which indicate an asymmetry in the proton sea in favor of the $u$ antiquarks for the case of helicity distributions, and an asymmetry in favor of the $d$ antiquarks for the case of transversity distributions.Comment: DIS2106 Proceeding

Middle Anisian (Bithynian to Illyrian?, Middle Triassic) Ammonoidea from Rüdersdorf (Brandenburg, Germany) with a revision of Beneckeia Mojsisovics, 1882 and notes on migratory pathways

Bithynian and Pelsonian (Anisian, Middle Triassic) Ammonoidea are generally rare in the Germanic Basin. Here, we describe ammonoids from the Jena and Rüdersdorf formations (Lower Muschelkalk) of Rüdersdorf (Brandenburg, Germany). This locality is peculiar in its isolated situation and its comparatively high diversity in ammonoids. This outcrop yielded several assemblages encompassing eight species: Balatonites ottonis (Buch, 1849), B. balatonicus (Mojsisovics, 1873), B. egregius (Arthaber, 1896), Beneckeia buchi (Alberti, 1834), Bulogites zoldianus (Mojsisovics, 1882), “Ceratites” antecedens (Beyrich, 1858), Discoptychites dux (Giebel, 1853) and Noetlingites strombecki (Griepenkerl, 1860). When the geographic distribution of these species are compared, it becomes evident that immigrants from the southeast and the southwest met in that region. Such immigrations were only possible during transgressions. Balatonites balatonicus, B. egregius and B. zoldianus are recorded from the area for the first time. Beneckeia is revised with a focus on Ben. buchi, one of the few true endemites of the Germanic Basin, using synchrotron data to describe its early ontogeny. The holotype of “Ceratites” antecedens is figured for the first time and a lectotype for Balatonites egregius is designated

Parton Distributions from Lattice QCD with Momentum Smearing

In this work we continue our effort to explore a recent proposal, which allows light-cone distributions to be extracted from purely spatial correlations, being thus accessible to lattice methods. In order to test the feasibility of this method, we present our latest results from a twisted mass lattice calculation of the flavor non-singlet momentum, helicity and transversity distributions of the nucleon. Furthermore, we apply a newly proposed momentum improved smearing, which has the potential to reach higher nucleon momenta as required for a safe matching procedure to the physical distribution functions.Comment: 7 pages, 5 figures, talk given at the 34th annual International Symposium on Lattice Field Theory, 24-30 July 2016, University of Southampton, UK. Revision: Added further references and moved acknowledgements to the bac

A growth model for RNA secondary structures

A hierarchical model for the growth of planar arch structures for RNA secondary structures is presented, and shown to be equivalent to a tree-growth model. Both models can be solved analytically, giving access to scaling functions for large molecules, and corrections to scaling, checked by numerical simulations of up to 6500 bases. The equivalence of both models should be helpful in understanding more general tree-growth processes

Scalar mesons and tetraquarks by means of lattice QCD

We study the light scalar mesons a_0(980) and kappa using N_f = 2+1+1 flavor lattice QCD. In order to probe the internal structure of these scalar mesons, and in particular to identify, whether a sizeable tetraquark component is present, we use a large set of operators, including diquark-antidiquark, mesonic molecule and two-meson operators. The inclusion of disconnected diagrams, which are technically rather challenging, but which would allow us to extend our work to e.g. the f_0(980) meson, is introduced and discussed