Anatomy of mixing-induced CP asymmetries in left–right symmetric models with spontaneous CP violation

Abstract

We investigate the pattern of CP violation in K 0 -K 0 , B 0 d -B 0 d and B 0 s -B 0 s mixing in a symmetrical SU(2) L ×SU(2) R ×U(1) model with spontaneous CP violation. We calculate the phases of the left and right quark mixing matrices beyond the small phase approximation and perform a careful analysis of all relevant restrictions on the model's parameters from ∆m K , ∆m B , ǫ, ǫ ′ /ǫ and the CP asymmetry in B 0 d → J/ψK 0 S . We find that, with current experimental data, the mass of the right-handed charged gauge boson, M 2 , is restricted to be in the range 2.75 to 13 TeV and the mass of the flavour-changing neutral Higgs boson, M H , in 10.2 to 14.6 TeV. This means in particular that the decoupling limit M 2 , M H → ∞ is already excluded by experiment. We also find that the model favours opposite signs of ǫ and sin 2β and is excluded if sin 2β > 0.1.

UbiquitousCPviolation in a top-inspired left-right model

“…However, according to Ref. 20, the SB-LR predicts sin 2β eff CKM < ∼ 0.1. This value is difficult to reconcile with recent precision measurements, which give sin 2β eff CKM = 0.79 ± 0.11 [25,26,27].…”

“…In the present work we retain the constraint given in Eq. (20), but generalize the mode of CP violation by allowing the Yukawa coupling matrices F and G to be (in principle) arbitrary 3 × 3 Hermitian matrices. At first glance it might appear that our generalization would hopelessly complicate matters by adding many new CP-odd phases.…”

“…The central values and uncertainties of the sines of the three rotation angles are taken from Ref. 20.…”

“…A good discriminator of the 64 solutions is the physically observable phase σ d (defined in Ref. 20 Figure 2 shows frequency plots of the various quark masses and rotation angles calculated using the input parameter sets displayed in Fig. 1.…”

“…Section VI describes the effects of imposing these additional constraints, an endeavour that is complicated somewhat by the presence of two new degrees of freedom, namely the Higgs and W 2 masses. [18,20,29]. The off-diagonal terms in the mass matrices may be written in terms of a Standard Model piece and a left-right piece,…”