No description available.

No description available.

Reproduction de : Thèse de doctorat : Physique : Lyon 1 : 2007. / Titre provenant de l'écran titre. Bibliogr. p. 245-253.

Proefschrift Universiteit van Amsterdam. / Met lit. opg. - Met samenvatting in het Nederlands.

Proefschrift Universiteit van Amsterdam. / Met lit. opg. - Met samenvatting in het Nederlands.

Proefschrift Universiteit van Amsterdam. / Met lit. opg. - Met samenvatting in het Nederlands.

Bibliography: p. 159-166. / There is a short introduction to the ideas of lattice theory, followed by an equally brief look at pure gauge QCD on the lattice. More details for either of these may be found in the references cited in each section, as well as in [143]. The bulk of this work deals with the problems encountered in placing fermions on to the lattice, and the techniques used for this purpose. The Nielsen-Ninomiya theorem is introduced, with a detailed treatment thereof relegated to an appendix. The two main fermion techniques, due to Wilson (1974); and Kogut and Susskind (1975) are dealt with in some detail. This is followed by a discussion of the construction of hadrons on the lattice, using either Wilson or Kogut-Susskind fermions. There is a chapter covering the algorithms used in numerical simulations of lattice QCD, with some examples illustrating them. The thesis concludes with a discussion of the results obtained thus far on the hadron spectrum, in both the quenched approximation as well as those obtained using dynamical quarks.

Note:

No description available.

Orientador: Gastão Inácio Krein / Banca: Mahir Saleh Hussein / Banca: Yogiro Hama / Banca: Eliane Angela Veit / Banca: Rogério Rosenfeld / Resumo: O formalismo de teoria de campos Fock-Tani, o qual foi originalmente desenvolvido na física atômica para tratar sistemas em que os graus de liberdade internos dos átomos não podem ser desprezados, é generalizado para sistemas de hádrons compostos. Partindo da representação no espaço de Fock dos estados hadrônicos num modelo de quarks, uma mudança de representação é implementada de tal maneira que os hádrons sejam descritos por operadores de campo de partículas elementares. A aplicação da transformação unitária ao Hamiltoniano microscópico de quarks dá origem a Hamiltonianos efetivos que descrevem interações quark-quark, hádron-hádron, e hádron-quark. Hamiltonianos bariônicos efetivos foram derivados no contexto de um modelo de quarks constituintes. Em particular, um potencial efetivo NN foi obtido, deslocamentos de fase singletos de spin foram calculados para este potencial e comparados aos deslocamentos de fase gerados pela troca de mésons 'ômega' do potencial de Bonn / Abstract: The field theoretic Fock-Tani formalism, originally developed in atomic physics to deal with systems where the internal degrees of freedom of atoms cannot be neglected, is generalized to composite hadronic systems. Starting from the Fock space representation of hadron bound states in a quark model, a change of representation is implemented by a unitary transformation such that the composite hadrons are redescribed by elementary-particle field operators. Application of the unitary transformation to the microscopic quark Hamiltonian gives rise to effective Hamiltonians that describe quark-quark, hadron-hadron, and quark-quark interactions. Effective baryon Hamiltonians are derived in the context of a constituent quark model. In particular, an efective NN Fock-Tani potential was obtained, spin-singlet phase shifts were calculated for this potential and compared with the ones generated by the 'ômega' exchange of the Bonn potential / Doutor