Combination of t(t)over-bar cross section measurements and constraints on the mass of the top quark and its decays into charged Higgs bosons

We combine measurements of the top quark pair production cross section in p (p) over bar collisions in the l + jets, ll, and tau l final states ( where l is an electron or muon) at a center of mass energy of root s = 1.96 TeV in 1 fb(-1) of data collected with the D0 detector. For a top quark mass of 170 GeV/c(2), we obtain sigma(t (t) over bar) = 8.18(-0.87)(+0.98) pb in agreement with the theoretical prediction. Based on predictions from higher order quantum chromodynamics, we extract a mass for the top quark from the combined t (t) over bar cross section, consistent with the world average of the top quark mass. In addition, the ratios of t (t) over bar cross sections in different final states are used to set upper limits on the branching fractions B(t -> H(+)b -> tau(+) vb) and B(t -> H(+)b -> c (s) over barb) as a function of the charged Higgs boson mass.

Measurement of the B+ Production Cross Section in pp Collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Upsilon production cross section in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the B-0 Production Cross Section in pp Collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A QCD sum rule approach to the charmonium - pion cross section

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

Measurement of the production cross section for pairs of isolated photons in pp collisions at root s=7 TeV

The integrated and differential cross sections for the production of pairs of isolated photons is measured in proton-proton collisions at a centre-of-mass energy of 7TeV with the CMS detector at the LHC. A data sample corresponding to an integrated luminosity of 36 pb(-1) is analysed. A next-to-leading-order perturbative QCD calculation is compared to the measurements. A discrepancy is observed for regions of the phase space where the two photons have an azimuthal angle difference Delta phi less than or similar to 2.8 rad.

Measurement of the X(3872) production cross section via decays to J/psi pi(+)pi(-) in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the cross section and angular correlations for associated production of a Z boson with b hadrons in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the t-channel single-top-quark production cross section and of the |V (tb)| CKM matrix element in pp collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the pp → ZZ production cross section and constraints on anomalous triple gauge couplings in four-lepton final states at √s = 8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Differential cross section measurements for the production of a W boson in association with jets in proton-proton collisions at √s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the cross section ratio σttbb/σttjj in pp collisions at √s = 8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Plant identification based on leaf midrib cross-section images using fractal descriptors

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

Measurement of the Z gamma production cross section in pp collisions at 8 TeV and search for anomalous triple gauge boson couplings

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Perturbative analysis of the triply differential cross section and circular dichroism in photo-double-ionization of He

We extend application of our lowest-order perturbative approach (in electron-electron correlation) for analysis of photo-double-ionization (PDI) of He [A.Y. Istomin et al., J. Phys. B 35, L543 (2002)] to excess energies up to 450 eV and to analysis of circular dichroism. We find that account of electron correlation in the final state to first order provides predictions for the triply differential cross section and circular dichroism that are in reasonable agreement with absolute data for excess energies up to 80 eV. For an excess energy of 450 eV, account of electron correlation in both initial and final states is necessary and the predicted triply differential cross sections are in agreement with absolute data only for large mutual ejection angles. We find that at excess energies of a few tens of eV, the PDI is dominated by the "virtual" knock-out mechanism, while the "direct" (on-shell) knock-out process gives only small contributions for large mutual ejection angles. As a result, we conclude that the circular dichroism effect at these energies originates from the nonzero electron Coulomb phase shifts.