Medium Modification of the Jet Properties

In the case that a dense medium is created in a heavy ions collision, high-E_t jets are expected to be broadened by medium-modified gluon emission. This broadening is directly related, through geometry, to the energy loss measured in inclusive high-p_t particle suppression. We present here the modifications of jet observables due to the presence of a medium for the case of azimuthal jet energy distributions and k_t-differential multiplicities inside the jets.Comment: 4 pages, 3 postscript figures. Proceedings for Quark Matter 200

Investment Dynamics in a DSGE Model with Heterogeneous Firms and Corporate Taxation

In this paper I study a new business cycle fact recently documented by Bachmann and Bayer (2011): the dispersion of the distribution of investment rates across firms is procyclical. Using data from German firm, the authors find a correlation coefficient between the standard deviation of investment distribution and the cyclical component of output of 0.45. They also report a correlation coefficient for US economy of 0.33. Using a model similar to Khan and Thomas's (2003), that is standard to heterogeneous firms literature, I obtain a correlation coefficient of 0.57. In the model I also consider a government sector that collects taxes on corporate profits. In such model, with a corporate tax of 23.5%, which corresponds to German economy, I obtain a correlation coefficient of 0.46 and when I consider a corporate tax rate of 18.79% that corresponds to US economy I find a correlation coefficient of 0.51.

Evolving Lorentzian wormholes supported by phantom matter with constant state parameters

In this paper we study the possibility of sustaining an evolving wormhole via exotic matter made out of phantom energy. We show that this exotic source can support the existence of evolving wormhole spacetimes. Explicitly, a family of evolving Lorentzian wormholes conformally related to another family of zero-tidal force static wormhole geometries is found in Einstein gravity. Contrary to the standard wormhole approach, where first a convenient geometry is fixed and then the matter distribution is derived, we follow the conventional approach for finding solutions in theoretical cosmology. We derive an analytical evolving wormhole geometry by supposing that the radial tension (which is negative to the radial pressure) and the pressure measured in the tangential directions have barotropic equations of state with constant state parameters. At spatial infinity this evolving wormhole, supported by this anisotropic matter, is asymptotically flat, and its slices $t=$ constant are spaces of constant curvature. During its evolution the shape of the wormhole expands with constant velocity, i.e without acceleration or deceleration, since the scale factor has strictly a linear evolution.Comment: 9 pages, 2 figures, Accepted for publication in Phys. Rev.

Antiangular Ordering of Gluon Radiation in QCD Media

We investigate angular and energy distributions of medium-induced gluon emission off a quark-antiquark antenna in the framework of perturbative QCD as an attempt toward understanding, from first principles, jet evolution inside the quark-gluon plasma. In-medium color coherence between emitters, neglected in all previous calculations, leads to a novel mechanism of soft-gluon radiation. The structure of the corresponding spectrum, in contrast with known medium-induced radiation, retains some properties of the vacuum case; in particular, it exhibits a soft divergency. However, as opposed to the vacuum, the collinear singularity is regulated by the pair opening angle, leading to a strict angular separation between vacuum and medium-induced radiation, denoted as antiangular ordering. We comment on the possible consequences of this new contribution for jet observables in heavy-ion collisions.Comment: 4 pages, 2 figures; v2. a number of minor improvements, figures updated, accepted for publication in PR

Charm quenching in heavy-ion collisions at the LHC

D-meson suppression in Pb-Pb collisions at the LHC due to charm quark in-medium energy loss is estimated within a model that describes the available quenching measurements at RHIC. The result is compared to that previously published by the author. The expected sensitivity of the ALICE experiment for studying charm energy loss via fully-reconstructed D^0-meson decays is also presented.Comment: 8 pages, 3 figures. To appear in the proceedings of Hot Quarks 2004: Workshop for Young Scientists on the Physics of Ultrarelativistic Nucleus-Nucleus Collisions, Taos Valley, New Mexico, 18-24 July 2004. Submitted to J. Phys.

Seletividade de inseticidas as diferentes fases de desenvolvimento do predador Doru luteipes (Scudder) (Dermaptera: forficulidae).

O predador Doru luteipes (Scudder) e um dos pincipais reguladores da populacao de Spodoptera frugiperda (J.E. Smith) e Helicoverpa zea (Boddie) na cultura de milho (Zea mays). O objetivo do trabalho foi estudar a seletividade de cinco inseticidas quimicos (deltametrina, lambdacialotrina, permetrina, diflubenzuron e triflumuron) e dois mecrobianos (Baculovirus e Bacillus thuringiensis (Berliner) sobre as diferentes fases de desenvolvimento do predador. Ovos e ninfas dos quatro instares receberam os inseticidas diretamente atraves de um pulverizador acoplado a uma esteira rolante. Adultos do predador receberam como alimento posturas de S. frugiperda, que foram pulverizadas com os diferentes inseticidas. Para os ovos, houve um efeito letal pronunciado com os inibidores de crescimento diflubenzuron (81,8% de mortalidade) e triflumuron (78,6%), sendo este tambem toxico para os instares ninfais (69,6%). Os inseticidas biologicos Baculovirus e B. thuringiensis foram seletivos a todas as fases de predador. A sobrevivencia do predador aos inseticidas foi crescente com o instar do inseto (S=39,5 + 7,79 I, R2 2 = 0,87). Os adultos tolerantes a todos os inseticidas (93,3% de sobrevivencia)

A rare case of colonic pseudolipomatosis

A 54-year-old man was referred to our department for colorectal cancer screening. The colonoscopy revealed, at the ascending colon, several white plaques, some confluent, interspersed with normal mucosa (Fig. 1). Biopsies were performed and the histopathological examination showed a fragment of polypoid colonic mucosa with optically empty vacuoles in the lamina propria (Fig. 2) and irregular cystic spaces of varying sizes, similar to adipocytes in the absence of inflammation or dysplasia. Colonic pseudolipomatosis is a benign and rare condition, with an estimated prevalence of 0.02-0.3 % in colonoscopic series, characterized by the presence of vacuoles with gas content in the lamina propria of the large intestine [1]. The incidence is more frequent between the sixth and seventh decade of life [2]. The pathogenesis remains unclear