Using a lattice of parallel and intersecting 4-branes in six-dimensional spacetime, we find a possible explanation for the observed quark masses of the three Standard Model generations,as well as for the observed CP violating phase in the Cabbibo-Kabayashi-Maskawa matrix. Localizing two massless 6-dimensional Dirac fermions via the warp factor(s) in the background of this geometry, effective mixing between the first two generations of the up and down quark sectors arise from the coupling of the fermion fields with the background metric. The alegbra of the six dimensional Dirac matrices is such that this mixing mechanism introduces a complex phase into the effective four dimensional quark flavor mixing matrix.The third generation quarks remain in the familiar four dimensions and may be identified with the single nonzero eigenvalue of the S_3L X S_3R invariant democratic mass matrix for each sector.

Tuesday, October 16th 2001, 13:10
Ernest Rutherford Physics Building, room 326