Quebra da simetria de sabor na interação de mésons charmosos com o núcleon
Carregando...
Data
2011-12-02
Autores
Fontoura, Carlos Eduardo S [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Nós empregamos modelos de quarks para investigar a quebra da simetria de sabor na interação de mésons e bárions charmosos com o núcleon. Nesses modelos a única fonte de quebra da simetria de sabor são as massas dos quarks u, d, s e c. Inicialmente, empregamos o modelo de decaimento forte 3P0 para calcular constantes de acoplamento hádron-hádron efetivas. Os elementos de matriz do operador de decaimento 3P0 foram calculados usando funções de onda hadrônicas determinadas através da diagonalização exata do Hamiltoniano microscópico de um modelo não-relativístico de quarks em uma base finita de funções de onda Gaussianas. Resultados numéricos foram obtidos para as amplitudes ππρ, KKρ, ¯D¯Dρ, NNπ, NΣsK, NΛc ¯D, NΣc ¯D, NΛsK e os efeitos da quebra de simetria foram avaliados para as correspondentes constantes de acoplamento. A seguir, investigamos o espalhamento a baixas energias dos mésons estranhos K e charmosos ¯D com o núcleon empregando um modelo microscópico de quarks inspirado na cromodinâmica quântica no calibre de Coulomb que confina a carga de cor e realiza a quebra dinâmica da simetria quiral. O Hamiltoniano microscópico do modelo incorpora um potencial de confinamento do tipo Coulomb e uma interação hiperfina de glúons transversos. Uma função de massa para os quarks constituintes ´e obtida pela solu¸c˜ao de uma equação de gap e funções de onda de estados ligados de mésons e bárions são obtidas no espaço de Fock usando um esquema de cálculo variacional. A seguir, tendo obtido as massas constituintes e as funções de ondas dos hádrons, uma interação efetiva méson-núcleon de alcance curto é derivada a partir do mecanismo de troca quark-glúon. Para descrever a física...
We employ quark models to investigate the breaking of flavor symmetry in the interaction of charmed mesons and baryons with the nucleon. The only source of flavor symmetry breaking are the masses of the quarksu,d,s, andc. Initially, we employ the 3 P0 strong decay model to obtain hadron-hadron effective coupling constants. The matrix elements of the3P0 decay operator were evaluated employing hadron wave-functions calculated by exact diagonalization of the microscopic quark model Hamiltonian in a finite basis of Gaussian wave-functions. Numerical results were determined for theππρ,KKρ, ¯ D¯Dρ,NNπ,NΣsK,NΛc ¯D,NΣc ¯D,NΛsK amplitudes and the symmetry breaking effects were evaluated for the corresponding coupling constants. Next, we investigate the strong interaction of strangeK and charmed ¯D mesons by nucleons at low energies using a microscopic quark model inspired in quantum chromodynamics in Coulomb gauge that confines color and realizes dynamical chiral symmetry breaking. The microscopic model Hamiltonian incorporates a confining Coulomb potential and a transverse-gluon hyperfine interaction. A constituent-quark mass function is obtained by solving a gap equation and baryon and meson bound-states are obtained in Fock space using a variational calculation. Next, having obtained the constituent-quark masses and the hadron waves functions, an effective short-range meson-nucleon interaction is derived from a quark-interchange mechanism. To describe long-distance physics vector- and scalar-meson exchanges obtained from effective Lagrangians are incorporated. The derived effective meson-baryonpotential is used in a Lippmann-Schwinger equation to obtain cross section and phase shifts. The obtained results are compared with recent similar calculations using the nonrelativistic... (Complete abstract click electronic access below)
We employ quark models to investigate the breaking of flavor symmetry in the interaction of charmed mesons and baryons with the nucleon. The only source of flavor symmetry breaking are the masses of the quarksu,d,s, andc. Initially, we employ the 3 P0 strong decay model to obtain hadron-hadron effective coupling constants. The matrix elements of the3P0 decay operator were evaluated employing hadron wave-functions calculated by exact diagonalization of the microscopic quark model Hamiltonian in a finite basis of Gaussian wave-functions. Numerical results were determined for theππρ,KKρ, ¯ D¯Dρ,NNπ,NΣsK,NΛc ¯D,NΣc ¯D,NΛsK amplitudes and the symmetry breaking effects were evaluated for the corresponding coupling constants. Next, we investigate the strong interaction of strangeK and charmed ¯D mesons by nucleons at low energies using a microscopic quark model inspired in quantum chromodynamics in Coulomb gauge that confines color and realizes dynamical chiral symmetry breaking. The microscopic model Hamiltonian incorporates a confining Coulomb potential and a transverse-gluon hyperfine interaction. A constituent-quark mass function is obtained by solving a gap equation and baryon and meson bound-states are obtained in Fock space using a variational calculation. Next, having obtained the constituent-quark masses and the hadron waves functions, an effective short-range meson-nucleon interaction is derived from a quark-interchange mechanism. To describe long-distance physics vector- and scalar-meson exchanges obtained from effective Lagrangians are incorporated. The derived effective meson-baryonpotential is used in a Lippmann-Schwinger equation to obtain cross section and phase shifts. The obtained results are compared with recent similar calculations using the nonrelativistic... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Cromodinamica quantica, Quantum chromodynamics
Como citar
FONTOURA, Carlos Eduardo S. Quebra da simetria de sabor na interação de mésons charmosos com o núcleon. 2011. 93 f. Tese (doutorado) - Universidade Estadual Paulista, Instituto de Física Teórica, 2011.