Measurement of event-shape observables in Z→ℓ+ℓ− events in pp collisions at √ s=7 TeV with the ATLAS detector at the LHC

Event-shape observables measured using charged particles in inclusive $Z$-boson events are presented, using the electron and muon decay modes of the $Z$ bosons. The measurements are based on an integrated luminosity of $1.1 {\rm fb}^{-1}$ of proton--proton collisions recorded by the ATLAS detector at the LHC at a centre-of-mass energy $\sqrt{s}=7$ TeV. Charged-particle distributions, excluding the lepton--antilepton pair from the $Z$-boson decay, are measured in different ranges of transverse momentum of the $Z$ boson. Distributions include multiplicity, scalar sum of transverse momenta, beam thrust, transverse thrust, spherocity, and $\mathcal{F}$-parameter, which are in particular sensitive to properties of the underlying event at small values of the $Z$-boson transverse momentum. The Sherpa event generator shows larger deviations from the measured observables than Pythia8 and Herwig7. Typically, all three Monte Carlo generators provide predictions that are in better agreement with the data at high $Z$-boson transverse momenta than at low $Z$-boson transverse momenta and for the observables that are less sensitive to the number of charged particles in the event.Comment: 36 pages plus author list + cover page (54 pages total), 14 figures, 4 tables, submitted to EPJC, All figures including auxiliary figures are available at http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2014-0

Charged-particle multiplicities in pp interactions at root s=900 GeV measured with the ATLAS detector at the LHC ATLAS Collaboration

The first measurements from proton–proton collisions recorded with the ATLAS detector at the LHC are presented. Data were collected in December 2009 using a minimum-bias trigger during collisions at a centre-of-mass energy of 900 GeV. The charged-particle multiplicity, its dependence on transverse momentum and pseudorapidity, and the relationship between mean transverse momentum and charged-particle multiplicity are measured for events with at least one charged particle in the kinematic range |η|500 MeVpT>500 MeV. The measurements are compared to Monte Carlo models of proton–proton collisions and to results from other experiments at the same centre-of-mass energy. The charged-particle multiplicity per event and unit of pseudorapidity at η=0η=0 is measured to be 1.333±0.003(stat.)±0.040(syst.)1.333±0.003(stat.)±0.040(syst.), which is 5–15% higher than the Monte Carlo models predict

Metabolite production by entomopathogenic fungi.

Os fungos entomopatogenicos produzem diferentes metabolitos, alguns dos quais sao importantes para a especializacao deste grupo de fungos. Poucos fungos entomopatogenicos foram examinados em detalhe com relacao aos seus metabolitos, e existe ainda menos informacao sobre o papel desempenhado por estes metabolitos no processo da doenca. No entanto, esta claro que algumas proteases sao fundamentais para penetracao do fungo pela cuticula do inseto. Estes fungos tem a capacidade rara de hidrolizar os derivados dos alcanos. Tambem produzem normalmente proteases muito ativas e de amplo espectro. Estas sao necessarias para a penetracao da epicuticula hidrofobica e da cuticula de alto conteudo proteico. As quitinases tambem estao envolvidas, mas normalmente tem uma importancia secundaria como enzimas de penetracao. A mais conhecida enzima de penetracao e a Prl - uma protease quimoelastase que e o maior produto enzimatico das estruturas de infeccao (apressorios) de Metarhizium anisopliae. O crescimento no hemocele envolve varias enzimas hidroliticas, e pode levar a formacao de compostos menores com efeitos prejudiciais para o hospedeiro. Estes podem ser simples venenos organicos, como por exemplo, o acido oxilico; mas frequentemente sao compostos maiores e muitos sao depsipeptideos. Os metabolitos dos fungos estao atualmente sendo estudados como potenciais inseticidas quimicos, e como agentes farmacologicos.Made available in DSpace on 2011-04-09T12:15:33Z (GMT). No. of bitstreams: 1 pab28abresp92.pdf: 1111985 bytes, checksum: 3533ce5c82e78c37fd4f812a160524b3 (MD5) Previous issue date: 2001-08-27199