The Cabibbo angle : an algebraic calculation

Quentin Duret (1) , Bruno Machet (1)

1 LPTHE - Laboratoire de Physique Théorique et Hautes Energies

We show that the Cabibbo angle theta_c satisfies the relation tan(2 theta_c)=-+/- 1/2 when universality for diagonal neutral currents of mass eigenstates is satisfied at the same level of accuracy as the absence of their off-diagonal counterparts. The predicted value is cos theta_c \approx 0.9732, only 7/10000 away from experimental results. No mass ratio appears in the calculation. theta_c occurs a priori for both quark species, and, showing that one recovers the standard dependence of leptonic and semi-leptonic decays of pseudoscalar mesons, we advocate, like for neutrinos and charged leptons, for a symmetrical treatment of u and d-type quarks.

Domaines: Physique des Hautes Energies - Phénoménologie [hep-ph]; Physique des Hautes Energies - Théorie [hep-th]

Quentin Duret, Bruno Machet. The Cabibbo angle : an algebraic calculation. 2006. ⟨hal-00085916v2⟩