6 research outputs found

    Measurement of forward W→eÎœW\to e\nu production in pppp collisions at s=8 \sqrt{s}=8\,TeV

    Get PDF
    A measurement of the cross-section for W→eÎœW \to e\nu production in pppp collisions is presented using data corresponding to an integrated luminosity of 2 2\,fb−1^{-1} collected by the LHCb experiment at a centre-of-mass energy of s=8 \sqrt{s}=8\,TeV. The electrons are required to have more than 20 20\,GeV of transverse momentum and to lie between 2.00 and 4.25 in pseudorapidity. The inclusive WW production cross-sections, where the WW decays to eÎœe\nu, are measured to be \begin{align*} \begin{split} \sigma_{W^{+} \to e^{+}\nu_{e}}&=1124.4\pm 2.1\pm 21.5\pm 11.2\pm 13.0\,\mathrm{pb},\\ \sigma_{W^{-} \to e^{-}\bar{\nu}_{e}}&=\,\,\,809.0\pm 1.9\pm 18.1\pm\,\,\,7.0\pm \phantom{0}9.4\,\mathrm{pb}, \end{split} \end{align*} where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. Differential cross-sections as a function of the electron pseudorapidity are measured. The W+/W−W^{+}/W^{-} cross-section ratio and production charge asymmetry are also reported. Results are compared with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. Finally, in a precise test of lepton universality, the ratio of WW boson branching fractions is determined to be \begin{align*} \begin{split} \mathcal{B}(W \to e\nu)/\mathcal{B}(W \to \mu\nu)=1.020\pm 0.002\pm 0.019, \end{split} \end{align*} where the first uncertainty is statistical and the second is systematic.A measurement of the cross-section for W→eÎœW \to e\nu production in pppp collisions is presented using data corresponding to an integrated luminosity of 2 2\,fb−1^{-1} collected by the LHCb experiment at a centre-of-mass energy of s=8 \sqrt{s}=8\,TeV. The electrons are required to have more than 20 20\,GeV of transverse momentum and to lie between 2.00 and 4.25 in pseudorapidity. The inclusive WW production cross-sections, where the WW decays to eÎœe\nu, are measured to be \begin{equation*} \sigma_{W^{+} \to e^{+}\nu_{e}}=1124.4\pm 2.1\pm 21.5\pm 11.2\pm 13.0\,\mathrm{pb}, \end{equation*} \begin{equation*} \sigma_{W^{-} \to e^{-}\bar{\nu}_{e}}=\,\,\,809.0\pm 1.9\pm 18.1\pm\,\,\,7.0\pm \phantom{0}9.4\,\mathrm{pb}, \end{equation*} where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination. Differential cross-sections as a function of the electron pseudorapidity are measured. The W+/W−W^{+}/W^{-} cross-section ratio and production charge asymmetry are also reported. Results are compared with theoretical predictions at next-to-next-to-leading order in perturbative quantum chromodynamics. Finally, in a precise test of lepton universality, the ratio of WW boson branching fractions is determined to be \begin{equation*} \mathcal{B}(W \to e\nu)/\mathcal{B}(W \to \mu\nu)=1.020\pm 0.002\pm 0.019, \end{equation*} where the first uncertainty is statistical and the second is systematic.A measurement of the cross-section for W → eÎœ production in pp collisions is presented using data corresponding to an integrated luminosity of 2 fb−1^{−1} collected by the LHCb experiment at a centre-of-mass energy of s=8 \sqrt{s}=8 TeV. The electrons are required to have more than 20 GeV of transverse momentum and to lie between 2.00 and 4.25 in pseudorapidity. The inclusive W production cross-sections, where the W decays to eÎœ, are measured to be σW+→e+Îœe=1124.4±2.1±21.5±11.2±13.0pb, {\sigma}_{W^{+}\to {e}^{+}{\nu}_e}=1124.4\pm 2.1\pm 21.5\pm 11.2\pm 13.0\kern0.5em \mathrm{p}\mathrm{b}, σW−→e−Μ‟e=809.0±1.9±18.1±7.0±9.4 pb, {\sigma}_{W^{-}\to {e}^{-}{\overline{\nu}}_e}=809.0\pm 1.9\pm 18.1\pm \kern0.5em 7.0\pm \kern0.5em 9.4\,\mathrm{p}\mathrm{b}, where the first uncertainties are statistical, the second are systematic, the third are due to the knowledge of the LHC beam energy and the fourth are due to the luminosity determination

    SNCA Gene Methylation in Parkinson’s Disease and Multiple System Atrophy

    No full text
    In recent years, epigenetic mechanisms have been implicated in the development of multifactorial diseases including neurodegenerative disorders. In Parkinson’s disease (PD), as a synucleinopathy, most studies focused on DNA methylation of SNCA gene coding alpha-synuclein but obtained results were rather contradictory. In another neurodegenerative synucleinopathy, multiple system atrophy (MSA), very few studies investigated the epigenetic regulation. This study included patients with PD (n = 82), patients with MSA (n = 24), and a control group (n = 50). In three groups, methylation levels of CpG and non-CpG sites in regulatory regions of the SNCA gene were analyzed. We revealed hypomethylation of CpG sites in the SNCA intron 1 in PD and hypermethylation of predominantly non-CpG sites in the SNCA promoter region in MSA. In PD patients, hypomethylation in the intron 1 was associated with earlier age at the disease onset. In MSA patients, hypermethylation in the promotor was associated with shorter disease duration (before examination). These results showed different patterns of the epigenetic regulation in two synucleinopathies—PD and MSA

    UnterstĂŒtzung expliziter Articulation Work : Interaktive Externalisierung und Abstimmung mentaler Modelle

    No full text
    Der Erfolg kooperativer Arbeit beruht auf einem gemeinsamen VerstĂ€ndnis der be- troffenen AblĂ€ufe durch die beteiligten Personen (Griffin und Hauser, 1992). Dieses gemeinsame VerstĂ€ndnis wird der Theorie von Strauss (1985) zufolge durch die stĂ€n- dige und unbewusste DurchfĂŒhrung von TĂ€tigkeiten zur Abstimmung mit anderen Individuen erreicht. Beim Auftreten von Situationen, die von den Beteiligten als kom- plex und problematisch wahrgenommen werden, mĂŒssen nach Strauss bewusst dezi- dierte AktivitĂ€ten der Abstimmung und zum Erreichen einer gemeinsamen Sichtweise durchgefĂŒhrt werden. Sowohl die Identifikation der Notwendigkeit von Abstimmungs- aktivitĂ€ten als auch deren DurchfĂŒhrung werden maßgeblich von den individuellen Wahrnehmungen der beteiligten Personen beeinflusst (Grudin, 1988). Auf diesen As- pekt geht Strauss nicht ein, so dass auch Arbeiten, die sich bei der Entwicklung von Instrumenten der UnterstĂŒtzung der Abstimmung auf dessen Arbeiten beziehen, die individuelle Dimension nicht explizit berĂŒcksichtigen. Ziel dieser Arbeit ist deshalb die UnterstĂŒtzung der Abstimmungsprozesse ĂŒber kooperative ArbeitsablĂ€ufe unter expli- ziter BerĂŒcksichtigung der BedĂŒrfnisse der beteiligten Individuen. Zu diesem Zweck werden Methoden aus der Theorie der mentalen Modelle nach Johnson-Laird (1981) mit den Anforderungen aus der Abstimmung von ArbeitsablĂ€ufen zusammengefĂŒhrt. Um die Abstimmung zu unterstĂŒtzen, setzt der hier vorgestellte Ansatz die koopera- tive Bildung und Diskussion diagrammatischer Modelle ein. Dieser Zugang ist aus der Theorie der Bildung und VerĂ€nderung mentaler Modelle (Seel, 1991) abgeleitet. Die Externalisierung der mentalen Modelle in Form von diagrammatischen Modellen ist nach Seel ein Weg zur Reflexion und Kommunikation derselben und ermöglicht so die Entwicklung einer gemeinsamen Sichtweise auf den kooperativen Arbeitsablauf. Me- thodisch baut die Arbeit auf Sturkturlegetechniken und Concept Mapping auf, welche sich zur Externalisierung mentaler Modelle eignen (Ifenthaler, 2006). Die dort vorge- schlagenen Methoden werden unter Bezugnahme auf die Abstimmung von individuel- len Sichtweisen auf ArbeitsablĂ€ufe zusammengefĂŒhrt. Wesentlich fĂŒr die kooperative Anwendung ist deren DurchfĂŒhrung auf einer durch mehrere Personen gleichzeitig zugĂ€nglichen und manipulierbaren ModellierungsoberflĂ€che (Dann, 1992). Die entwi- ckelte Methodik wird deshalb durch ein Tabletop Interface - eine horizontale Interak- tionsoberflĂ€che mit rechnerbasierten UnterstĂŒtzungsfunktionen - zu einem Instrument ergĂ€nzt, mit dem die DurchfĂŒhrung von AbstimmungsaktivitĂ€ten unterstĂŒtzt werden kann. Das Tabletop Interface ermöglicht die kooperative Bildung von Modellen mittels physischen Bausteinen, die auf der InteraktionsoberflĂ€che platziert werden. Das Mo- dell kann so unmittelbar und simultan von mehreren Personen erfasst und manipuliert werden. Technologisch basiert das System auf der Identifikation der Bausteine mittels Markern, die durch eine Kamera in Echtzeit erfasst werden. Die erfasste Information wird durch das System interpretiert, so dass AktivitĂ€ten zur Modellbildung identifi- ziert werden können. Die Darstellung von Information zum erstellten Modell erfolgt durch RĂŒckprojektion auf die InteraktionsoberflĂ€che und einen Bildschirm, der als er- weiterter Ausgabekanal fĂŒr nicht auf der OberflĂ€che darstellbare Information dient. Durch zusĂ€tzliche RechnerunterstĂŒtzung werden kooperationsunterstĂŒtzende Maßnah- men wie die Wiederherstellung vergangener ModellzustĂ€nde ermöglicht. Die persis- tente Ablage der erstellten Modelle erfolgt als Topic Map, einem standardisierten Datenformat zur flexiblen ReprĂ€sentation semantischer Netze, das eine Wieder- und Weiterverwendbarkeit der erstellten Modelle gewĂ€hrleistet. Die EffektivitĂ€t der UnterstĂŒtzung von AbstimmungsaktivitĂ€ten durch das System wird im Rahmen einer empirischen Untersuchung untersucht. Dabei wird die Verwend- barkeit des interaktiven Systems selbst, dessen Nutzen bei der Abstimmung mentaler Modelle sowie letztendlich die Auswirkungen bei der DurchfĂŒhrung von Abstimmungs- aktivitĂ€ten in Arbeitsprozessen untersucht. Die Ergebnisse zeigen, dass das Werkzeug verstĂ€ndlich und benutzbar ist und das Instrument in seiner Gesamtheit sowohl posi- tive Wirkungen auf die Kooperation zwischen den beteiligten Personen hat als auch die Bildung einer gemeinsamen Sichtweise auf den betrachteten Arbeitsablauf hat.Successful cooperative work requires that the involved workers develop a common un- derstanding of the modalities of their interaction. According to Strauss (1985), com- mon understanding emerges from continuously and unconsciously conducted activities for alignment of understanding. In situation perceived to be complex or problematic by the involved persons, Strauss suggests that alignment activities have to triggered and conducted deliberately. Individual perceptions affect both, the identification of the need for alignment and alignment itself (Grudin, 1988). Strauss does not explicit- ly address this aspect in his theory. Approaches that support alignment based upon Strauss' work thus also largely ignore the individual, cognitive dimension of alignment. Accordingly, this work aims at extending the scope of alignment support by explicitly considering the perceptions and needs of individuals. The theory of mental models (Johnson-Laird, 1981) here is used to extend Strauss' concepts and develop effective support for developing a common understanding of work processes. Following the theory of mental model development by (Seel, 1991), the cooperative creation of diagrammatic models as representations of mental models can aid their alignment and the development of a common understanding. Suitable methods for building representations of mental models include structure elaboration techniques and concept mapping (Ifenthaler, 2006). Both methods have properties that are support the cooperative creation of models. In this work, they are integrated to form a method that is useable in the context of the alignment of cooperative work. The main feature for cooperation support is that modeling takes places on a simultaneously accessible and manipulable modeling surface (Dann, 1992). The method thus is complemented with a tabletop interface - a horizontally mounted interaction surface that is augmented with computer support - to effectively support the alignment of individual views on cooperative work processes. Tangible tokens are used to cooperatively build models on the interaction surface. By physically placing the tokens, the model can be manipulated simultaneously by several people. Token identification is based on visual markers that are tracked by a camera in real time. The gathered information is interpreted by the system to identify modeling activities. Model information is displayed by back-projecting it onto the surface from underneath. An traditional screen is provided as an additional output channel for information that cannot be displayed directly on the interaction surface. Cooperation is further supported by additional features like reconstruction support for former model states. Persistent model representation is based upon the standardized XML Topic Map format, which allows for a reusable, self-contained representation of generic semantic networks. The systems's effectiveness in supporting the alignment of work is tested in an empirical study. In three steps, the system's usability, its effects on the alignment of mental models and the effectiveness in supporting the development of a common understanding of work processes are examined. The results of the study show that the system is comprehensible and useable. Positive effects on both, the cooperation among people during modeling and the alignment of individual views of cooperative work, have been observed.von Stefan OpplAbweichender Titel laut Übersetzung der Verfasserin/des VerfassersZsfassung in engl. SpracheWien, Techn. Univ., Diss., 2010(VLID)161433

    Measurement of forward W → eÎœ production in pp collisions at √s=8 TeV

    No full text

    Measurement of CP Violation in B0→D+D− Decays

    No full text
    The C ⁣PC\!P violation observables SS and CC in the decay channel B0 ⁣→D+D−B^0 \!\rightarrow D^+ D^- are determined from a sample of proton-proton collisions at centre-of-mass energies of 77 and 88 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 3 fb−13~ {\text {fb}}^{-1}. The observable SS describes C ⁣PC\!P violation in the interference between mixing and the decay amplitude, and CC parametrizes direct C ⁣PC\!P violation in the decay. The following values are obtained from a flavour-tagged, decay-time-dependent analysis: \begin{align*} S &= -0.54 \, ^{+0.17}_{-0.16} \, \text{(stat)} \pm 0.05 \, \text{(syst)}\,, \\ C &= \phantom{-}0.26 \, ^{+0.18}_{-0.17} \, \text{(stat)} \pm 0.02 \, \text{(syst)}\,. \end{align*} These values constrain higher-order Standard Model corrections to be small.The CP violation observables S and C in the decay channel B0→D+D- are determined from a sample of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 3  fb-1. The observable S describes CP violation in the interference between mixing and the decay amplitude, and C parametrizes direct CP violation in the decay. The following values are obtained from a flavor-tagged, decay-time-dependent analysis: S=-0.54-0.16+0.17(stat)±0.05(syst), C=0.26-0.17+0.18(stat)±0.02(syst). These values provide evidence for CP violation at a significance level of 4.0 standard deviations. The phase shift due to higher-order standard model corrections is constrained to a small value of Δϕ=-0.16-0.21+0.19  rad.The CPCP violation observables SS and CC in the decay channel B0 ⁣→D+D−B^0 \!\rightarrow D^+ D^- are determined from a sample of proton-proton collisions at center-of-mass energies of 7 and 8 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 3 fb−1^{-1}. The observable SS describes CPCP violation in the interference between mixing and the decay amplitude, and CC parametrizes direct CPCP violation in the decay. The following values are obtained from a flavor-tagged, decay-time-dependent analysis: \begin{align*} S &= -0.54 \, ^{+0.17}_{-0.16} \, \text{(stat)} \pm 0.05 \, \text{(syst)}\,,\newline C &= \phantom{-}0.26 \, ^{+0.18}_{-0.17} \, \text{(stat)} \pm 0.02 \, \text{(syst)}\,. \end{align*} These values provide evidence for CPCP violation at a significance level of 4.0 standard deviations. The phase shift due to higher-order Standard Model corrections is constrained to a small value of \begin{align*} \Delta\phi = -0.16\,^{+0.19}_{-0.21}\,\text{rad}\,. \end{align*
    corecore