QCD effective charge and the structure function F-2 at small-x

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Inclusive and differential measurements of the t(t)over-bar charge asymmetry in proton-proton collisions root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the muon charge asymmetry from W boson decays

We present a measurement of the muon charge asymmetry from W boson decays using 0.3 fb(-1) of data collected at root s =1.96 GeV between 2002 and 2004 with the D0 detector at the Fermilab Tevatron (p) over bar Collider. We compare our findings with expectations from next-to-leading-order calculations performed using the CTEQ6.1M and MRST04 NLO parton distribution functions. Our findings can be used to constrain future parton distribution function fits.

Measurement of the forward-backward charge asymmetry in top-quark pair production

We present the first measurement of the integrated forward-backward charge asymmetry in top-quark-top-antiquark pair (t (t) over bar) production in proton-antiproton (p (p) over bar) collisions in the lepton+jets final state. Using a b-jet tagging algorithm and kinematic reconstruction assuming t (t) over bar +X production and decay, a sample of 0.9 fb(-1) of data, collected by the D0 experiment at the Fermilab Tevatron Collider, is used to measure the asymmetry for different jet multiplicities. The result is also used to set upper limits on t (t) over bar +X production via a Z' resonance.

Measurement of the Forward-Backward Charge Asymmetry and Extraction of sin(2)theta(eff)(W) in pp -> Z/gamma(*)+X -> e(+)e(-)+X Events Produced at s=1.96 TeV

We present a measurement of the forward-backward charge asymmetry (A(FB)) in pp -> Z/gamma(*)+X -> e(+)e(-)+X events at a center-of-mass energy of 1.96 TeV using 1.1 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron collider. A(FB) is measured as a function of the invariant mass of the electron-positron pair, and found to be consistent with the standard model prediction. We use the A(FB) measurement to extract the effective weak mixing angle sin(2)theta(eff)(W)=0.2326 +/- 0.0018(stat)+/- 0.0006(syst).

Measurement of the Electron Charge Asymmetry in p(p)over-bar -> W plus X -> e nu plus X Events at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evidence for an anomalous like-sign dimuon charge asymmetry

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evidence for an Anomalous Like-Sign Dimuon Charge Asymmetry

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of sin(2)theta(l)(eff) and Z-light quark couplings using the forward-backward charge asymmetry in p(p)over-bar -> Z/gamma* -> e(+)e(-) events with L=5.0 fb(-1) at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the anomalous like-sign dimuon charge asymmetry with 9 fb(-1) of p(p)over-bar collisions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for associated Higgs boson production using like charge dilepton events in p(p)over-bar collisions at root s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for a Vectorlike Quark with Charge 2/3 in t plus Z Events from pp Collisions at root s 7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Fundamental Limits on Wavelength, Efficiency and Yield of the Charge Separation Triad

In an attempt to optimize a high yield, high efficiency artificial photosynthetic protein we have discovered unique energy and spatial architecture limits which apply to all light-activated photosynthetic systems. We have generated an analytical solution for the time behavior of the core three cofactor charge separation element in photosynthesis, the photosynthetic cofactor triad, and explored the functional consequences of its makeup including its architecture, the reduction potentials of its components, and the absorption energy of the light absorbing primary-donor cofactor. Our primary findings are two: First, that a high efficiency, high yield triad will have an absorption frequency more than twice the reorganization energy of the first electron transfer, and second, that the relative distance of the acceptor and the donor from the primary-donor plays an important role in determining the yields, with the highest efficiency, highest yield architecture having the light absorbing cofactor closest to the acceptor. Surprisingly, despite the increased complexity found in natural solar energy conversion proteins, we find that the construction of this central triad in natural systems matches these predictions. Our analysis thus not only suggests explanations for some aspects of the makeup of natural photosynthetic systems, it also provides specific design criteria necessary to create high efficiency, high yield artificial protein-based triads.

Measurement of the Electron Charge Asymmetry in Inclusive W Production in pp Collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Charge injection in an LED with a hybrid composite as the emissive layer

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)