Daniel T. da Silva

Bound State Correction in CP Violation

We study hadronic weak decays using an approach which consists in a mapping technique, the Fock-Tani formalism, in order to obtain an effective weak Hamiltonian starting from a contact microscopic interaction. An additional effect is manifest in this formalism associated to the extended nature of mesons: bound-state corrections which can be related to CP violation parameters.

The Ds1(2536)+ Decay Widths in the C3P0 Model

The Fock-Tani representation is a field theory formalism appropriated for the simultaneous treatment of composite particles and their constituents. The 3P0 model is a typical decay model which considers only OZI-allowed strong decays. The model considers a quark-antiquark pair created with the vacuum quantum numbers in the presence of the initial state meson. It is described as the non-relativistic limit of the pair creation Hamiltonian. Applying the Fock-Tani transformation to the microscopic Hamiltonian of the pair creation produces the characteristic expansion in powers of the wavefunction, where the 3P0 model is the lowest order in the expansion. The corrected 3P0 model (C3P0) is obtained from higher orders in the expansion, by the introduction of the bound state kernel Δ, called the bound state correction. The goal of this work is to study the application of the 3P0 model and C3P0 model in detail for the strange charmed meson sector (DSJ meson). In particular, we shall calculate the decay amplitudes ...

X(1835) Decay in the Fock-Tani Formalism

In this work we have obtained an effective Hamiltonian to describe the strong decay of pseudoscalar glueball, where the microscopic interaction between the constituent gluons have been taking into account. The pseudoscalar glueball candidate we have considered here is the X(1835) resonance. In our calculation the X(1835) was a pure glueball.

Photon-Photon Interaction in Glueball Production

In the last years many exotic states have been identified in several colliders around the world. One of the exotic states provided in QCD is the glueball. Using a non-relativistic gluon bound-state model, we compute Γ(G → γγ), where G is a pseudoscalar, tensor, or scalar digluon. For the starting from the amplitudes we considers the process γγ → g∗g∗ at threshold, where the amplitudes are obtained in perturbative QCD at lowest order by deriving them from QED calculation and the g∗s are massive constituent gluons. In this calculation the unknown parameters of the model, such as the digluon wave function, are obtained using measured values of Γ(J/Ψ → Gγ). Our theorical results are compared with the present experimental limits for the various glueballs candidates.

A Heavy-Light Quark Potential

In many studies of meson-baryon interactions with short one gluon exchange potential (OGEP), usually a full non-relativistic reduction, at the quark level Hamiltonian, is performed. In systems like ηcN, light and heavy quarks are present, which in principle would require only a partial non-relativistic reduction. We shal start from a JKJ relativistic quark Hamiltonian and apply a partial non-relativistic reduction in order to obtain a OGEP between heavy and light quarks (heavy-light quark potential).

Light Meson Decay with Gaussian Confinement in a JKJ Decay Model

A form to describe hadron strong decays is in terms of quark and gluon degrees of freedom in microscopic decay models. Initially we assume that strong decays are driven by the same inter-quark Hamiltonian which determines the spectrum, and that it incorporates gaussian confinement. An A → BC decay matrix element of the JKJ Hamiltonian involves a pair-production current matrix elements times a scattering matrix element. Diagrammatically this corresponds to an interaction between an initial line and produced pair. In this work we apply the model to the light meson sector and calculate the decay rate, comparing with the experimental values.

DSJMesons Decay in the C3P0Model

Having its origin in a successful mapping technique, the Fock‐Tani formalism, has produced a corrected 3 P 0 model ( C 3 P 0 model), which retains the basic aspects of the 3 P 0 predictions with the inclusion of bound‐state corrections. In high energy collisions many new mesons have been discovered in particular the enigmatic D S0 + (2317) and D S1 + (2460). The model is applied for D SJ mesons decay. The amplitude and its respective decay rates are evaluated.

D[sub SJ] Mesons Decay in the C[sup 3]P[sub 0] Model

Having its origin in a successful mapping technique, the Fock‐Tani formalism, has produced a corrected 3 P 0 model ( C 3 P 0 model), which retains the basic aspects of the 3 P 0 predictions with the inclusion of bound‐state corrections. In high energy collisions many new mesons have been discovered in particular the enigmatic D S0 + (2317) and D S1 + (2460). The model is applied for D SJ mesons decay. The amplitude and its respective decay rates are evaluated.

DSJ Mesons Decay in the C3P0 Model

Having its origin in a successful mapping technique, the Fock‐Tani formalism, has produced a corrected 3 P 0 model ( C 3 P 0 model), which retains the basic aspects of the 3 P 0 predictions with the inclusion of bound‐state corrections. In high energy collisions many new mesons have been discovered in particular the enigmatic D S0 + (2317) and D S1 + (2460). The model is applied for D SJ mesons decay. The amplitude and its respective decay rates are evaluated.

f0(1710) DECAY IN THE FOCK–TANI FORMALISM

We investigate the two-meson decay modes for f0(1710). In this calculation, we consider this resonance as a glueball. The Fock–Tani formalism is introduced to calculate the decay width.