ar X iv : h ep - p h / 98 10 28 2 v 2 1 5 Ja n 19 99 UM - P - 98 / 52 The Scalar Sector in 331 Models

ar X iv : h ep - p h / 98 07 20 1 v 2 3 1 Ju l 1 99 8 UM - P - 97 / 21 Fermion Masses and Mixing in 331 Models with Horizontal Symmetry

The possibility of adding an SU (2) horizontal symmetry to the 331 model is studied. It is found that simple, anomaly-free fermion assignments can be made which lead to plausible results for fermion masses and mixings. In particular, all particles of the first generation are massless at tree-level, and the CKM matrix acquires a realistic form.

ar X iv : h ep - p h / 98 07 20 1 v 1 1 J ul 1 99 8 UM - P - 97 / 21 Fermion Masses and Mixing in 331 Models with Horizontal Symmetry

The possibility of adding an SU (2) horizontal symmetry to the 331 model is studied. It is found that simple, anomaly-free fermion assignments can be made which lead to plausible results for fermion masses and mixings. In particular, all particles of the first generation are massless at tree-level, and the CKM matrix acquires a realistic form.

ar X iv : h ep - p h / 98 03 29 2 v 2 1 1 M ar 1 99 8 NATURE OF THE SCALAR a 0 ( 980 ) AND f 0 ( 980 ) - MESONS

It is presented a critical consideration of all unusual properties of the scalar a 0 (980) and f 0 (980)-mesons in the four-quark, two-quark and molecular models. The arguments are adduced that the four-quark model is more preferable. It is discussed the complex of experiments that could finally resolve this issue.

ar X iv : h ep - p h / 98 02 41 9 v 1 2 5 Fe b 19 98 COURSE LARGE N QCD

ar X iv : h ep - p h / 98 03 29 2 v 1 1 0 M ar 1 99 8 NATURE OF THE SCALAR a 0 ( 980 ) AND f 0 ( 980 ) - MESONS

It is presented a critical consideration of all unusual properties of the scalar a 0 (980) and f 0 (980)-mesons in the four-quark, two-quark and molecular models. The arguments are adduced that the four-quark model is more preferable. It is discussed the complex of experiments that could finally resolve this issue.