Five-quark qqqq (q) over bar components in the Delta(1232) are shown to contribute significantly to Delta(1232)-> N pi decay through quark-antiquark annihilation transitions. These involve the overlap between the qqq and the qqqq (q) over bar components and may be triggered by the confining interaction between the quarks. With a similar to 10% admixture of five-quark components in the Delta(1232) the decay width can be larger by factors similar to 2 - 3 over that calculated in the nonrelativistic quark model with three valence quarks, depending on the details of the confining interaction. The effect of transitions between the qqqq (q) over bar components themselves on the calculated decay width is however small. The large contribution of the quark-antiquark annihilation transitions thus may compensate the underprediction of the width of the Delta(1232) by the valence quark model, once the Delta(1232) contains qqqq (q) over bar components with similar to 10% probability.
机构:
Inst Politecn Nacl, UP Adolfo Lopez Mateos, Escuela Super Fis & Matemat, Dept Fis, Mexico City 07738, DF, MexicoInst Politecn Nacl, UP Adolfo Lopez Mateos, Escuela Super Fis & Matemat, Dept Fis, Mexico City 07738, DF, Mexico