Transmission coefficient and two-fold degenerate discrete spectrum of spin-1 bosons in a double-step potential

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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)

Measurement of electroweak production of two jets in association with a Z boson in proton-proton collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of top quark-antiquark pair production in association with a W or Z boson in pp collisions at root s=8 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influence of a Z+(1540) resonance on K+N scattering

The impact of a (I=0, JP=1/2+)Z+(1540) resonance with a width of 5 MeV or more on the K+N(I=0) elastic cross section and on the P01 phase shift is examined within the KN meson-exchange model of the Jülich group. It is shown that the rather strong enhancement of the cross section caused by the presence of a Z + with the above properties is not compatible with the existing empirical information on KN scattering. Only a much narrower Z+ state could be reconciled with the existing data - or, alternatively, the Z + state must lie at an energy much closer to the KN threshold.

Conservation laws for Z(N) symmetric quantum spin models and their exact ground state energies

We derive an infinite set of conserved charges for some Z(N) symmetric quantum spin models by constructing their Lax pairs. These models correspond to the Potts model, Ashkin-Teller model and the particular set of self-dual Z(N) models solved by Fateev and Zamolodchikov [6]. The exact ground state energy for this last family of hamiltonians is also presented. © 1986.

New Higgs interactions in ZZ gamma and Z gamma gamma production

The effect of new operators that only modify the bosonic couplings of the Higgs boson, without altering the WW gamma or WWZ three-point functions, are examined in the e(+)e(-) --> ZZ gamma and Z gamma gamma processes. We analyse the constraints on these interactions that can be imposed by the LEP II collider at CERN and at the Next Linear Collider. (C) 1998 Elsevier B.V. B.V.

Hamiltonian formulation of anomaly free chiral bosons

Starting out with an anomaly free lagrangian formulation for chiral scalars, which includes a Wess-Zumino term (to cancel the anomaly), we formulate the corresponding hamiltonian problem. Then we use the (quantum) Siegel invariance to choose a particular solution, which turns out to coincide with the one obtained by Floreanini and Jackiw. © 1988.

Excited fermion contribution to Z(0) physics at one loop

We investigate the effects induced by excited leptons at the one-loop level in the observables measured on the Ζ peak at LEP. Using a general effective Lagrangian approach to describe the couplings of the excited leptons, we compute their contributions to both oblique parameters and Ζ partial widths. Our results show that the new effects are comparable to the present experimental sensitivity, but they do not lead to a significant improvement on the available constraints on the couplings and masses of these states.