Heavy-flavor production in pp and Pb-Pb collisions at LHC with ALICE

We report recent results from the ALICE experiment the Large Hadron Collider on open charmed hadron production in pp collisions at $\sqrt{s} = 2.76$ and 7 TeV, and Pb-Pb collisions at $\sqrt{\mathrm{s}_{_{\mathrm{NN}}}} = 2.76$ TeV. Open charmed hadrons are kinematically fully reconstructed in the hadronic decay channels \DtoKpi, \DtoKpipi, and \DstartoDpi %$D^0\rightarrow K^-\pi^+$, $D^+\rightarrow K^-\pi^+ \pi^+$, and $D^{*+} \rightarrow D^0 (K^-\pi^+) + \pi^+$ and identified through their invariant mass. Combinatorial background is minimized by selecting a displaced vertex topology. Inclusive charm and beauty production is measured by detecting electrons (muons) from semi-leptonic decays of open charmed and beauty hadrons in the central (forward) region. Comparison to results from state-of-the-art QCD calculations is given. First results on nuclear modifications factors in Pb--Pb collisions from hadronic and semi-leptonic decays are presented.Comment: proceedings of the Hadron 2011 Conference, 13-17 June 2011, Munich, Germany, 6 pages, 3 fig

Heavy-Flavor Collectivity - Light-Flavor Thermalization at RHIC

Flow measurements of multi-strange baryons from Au + Au collisions at RHIC energies demonstrate that collectivity develops before hadronization, among partons. To pin down the partonic EOS of matter produced at RHIC, the status of thermalization in such collisions has to be addressed. We propose to measure collective flow of heavy-flavor quarks, e.g. charm quarks, as an indicator of thermalization of light flavors ($u,d,s$). The completion of the time of flight barrel and the proposed upgrade with a $\mu$Vertex detector for heavy-flavor identification in STAR are well suited for achieving these goals.Comment: proceedings of the ISMD 2005 conference, Kromeriz, Czech Republic; 6 pages, 4 figure

Time ordered perturbation theory for non-local interactions; applications to NCQFT

In the past decades, time ordered perturbation theory was very successful in describing relativistic scattering processes. It was developed for local quantum field theories. However, there are field theories which are governed by non-local interactions, for example non-commutative quantum field theory (NCQFT). Filk (Phys. Lett. B 376 (1996) 53) first studied NCQFT perturbatively obtaining the usual Feynman propagator and additional phase factors as the basic elements of perturbation theory. However, this treatment is only applicable for cases, where the deformation of space-time does not involve time. Thus, we generalize Filk's approach in two ways: First, we study non-local interactions of a very general type able to embed NCQFT. And second, we also include the case, where non-locality involves time. A few applications of the obtained formalism will also be discussed.Comment: 21 pages, 2 figure

DD‾D\overline{D} momentum correlations versus relative azimuth as a sensitive probe for thermalization

In high-energy nuclear collisions at LHC, where a QGP might be created, the degree of thermalization at the partonic level is a key issue. Due to their large mass, heavy quarks are a powerful tool to probe thermalization. We propose to measure azimuthal correlations of heavy-quark hadrons and their decay products. Changes or even the complete absence of these initially existing azimuthal correlations in $Pb-Pb$ collisions might indicate thermalization at the partonic level. We present studies with PYTHIA for $p-p$ collisions at 14 TeV using the two-particle transverse momentum correlator ${}$ as a sensitive measure of potential changes in these azimuthal correlations. Contributions from transverse radial flow are estimated.Comment: proceedings of the ISMD08 conference, DESY, Hamburg, Germany; to appear in DESY-PROC, 5 pages, 4 fig

Country differences in technology experience: The effect of teletext on iTV adoption in the United Kingdom

This study found that participant’s previous teletext experience and previous iTV experience influenced their openness towards using interactive television in planning independent longhaul holidays. The study surveyed participants for their previous interactive media experience (internet, iTV and teletext) before viewing a linear or interactive television destination promotion. Two ad models (impulse and telescopic) were tested from two program formats (travel program segment and ad break in a lifestyle program). These were aired on a video-on-demand network in London (UK) with 164 people out of a total of 375 participating all the way to the final steps of the study. Participants were most experienced with the Internet (mean 6.29 on 1-7scale) and 50% had had experience with an interactive television provider other than the VOD network. 70% had experience with teletext. Overall, participants felt positively towards interactive television as an information source for holiday planning. Those with teletext experience or iTV experience were more open to iTV than those without such experience. Furthermore, actual interaction with the treatment seemed to moderate the previous experience – iTV attractiveness link. This demonstrated that although previous technology experiences can transfer to new media, the actual experience of using the new media is also a powerful factor

A comparison of three interactive television AD formats

This study explores the effects of interacting with three current interactive television (iTV) ad formats, using an Australian audience panel. Interaction with iTV ads has positive effects on awareness and net positive thoughts, which increase purchase intentions compared with the influence of regular ads. The telescopic format represents the best format, likely because it makes the most of the entertaining possibilities of iTV by offering additional long-form video; its superior performance cannot be explained readily by self-selection effects. The results suggest that the effectiveness of iTV ads should be measured by their interaction rate rather than the much smaller response rate, and iTV advertisers should consider ways to maximize interaction and response rates

The three-dimensional BF Model with Cosmological Term in the Axial Gauge

We quantize the three-dimensional $BF$-model using axial gauge conditions. Exploiting the rich symmetry-structure of the model we show that the Green-functions correspond to tree graphs and can be obtained as the unique solution of the Ward-Identities. Furthermore, we will show that the theory can be uniquely determined by symmetry considerations without the need of an action principle.Comment: one reference added, transmission errors correcte