Related papers: How much space is left for a new family?
The fourth Standard Model (SM) family quarks and weak iso-singlet quarks The fourth Standard Model (SM) family quarks and weak iso-singlet quarks predicted by ${\rm E}_{6\text{}}$ GUT are considered. The spin-average of the pseudoscalar…
The CKM-matrix V is written as a linear combination of the unit matrix I and a matrix U which causes intergenerational-mixing. It is shown that such a V results from a class of quark-mass matrices. The matrix U has to be hermitian and…
It is proposed that all flavor mixing is caused by the mixing of the three quark and lepton families with vectorlike fermions in 5 + 5-bar multiplets of SU(5). This simple assumption implies that both V_{CKM} and U_{MNS} are generated by a…
We obtain constraints on possible structures of mass matrices in the quark sector by using as experimental restrictions the determined values of the quark masses at the $M_Z$ energy scale, the magnitudes of the quark mixing matrix elements…
We present recent results on searches for the fourth generation quarks performed at the CMS and ATLAS experiments at LHC.
We study extensions of the Standard Model where the charged current weak interactions are governed by the CKM matrix and where all tree-level decays are dominated by their Standard Model contribution. We constrain both analytically and…
We suggest an approach to explain the observed pattern of the neutrino masses and mixing which employs the weakly broken quark-lepton symmetry and does not require introduction of an ad hoc symmetry of the neutrino sector. The mass matrices…
We construct a model of quark-lepton unification at the TeV scale based on an $SU(4)$ gauge symmetry, while still having acceptable neutrino masses and enough suppression in flavor changing neutral currents. An approximate $U(2)$ flavor…
We have recently argued that quark masses may follow a simple scaling law. In this paper we build a simple mass matrix for quarks that can reproduce the scaling law expression. The simple mass matrices of the model are then generalized…
In the democratic universal seesaw model, the mass matrices are given by \bar{f}_L m_L F_R + \bar{F}_L m_R f_R + \bar{F}_L M_F F_R (f: quarks and leptons; F: hypothetical heavy fermions), m_L and m_R are universal for up- and down-fermions,…
Using the theoretical and experimental results on $B \to X_s \gamma$, a four-generation SM is analyzed to constrain the combination of the $4\times 4$ Cabibbo-Kobayashi-Maskawa factor $V_{t^\prime s}^* V_{t^\prime b}$ as a function of the…
Recent neutrino data have been favourable to a nearly bimaximal mixing, which suggests a simple form of the neutrino mass matrix. Stimulated by this matrix form, a possibility that all the mass matrices of quarks and leptons have the same…
Within the broad context of quark-lepton unification, we investigate the implications of broken continuous family symmetries which result from requiring that in the limit of exact symmetry, the Dirac mass matrices yield hierarchical masses…
We perform a systematical analysis of the $A_4$ modular models with generalized CP for the masses and flavor mixing of quarks and leptons, and the most general form of the quark and lepton mass matrices is given. The CP invariance requires…
We study the one-loop contribution of the down-type quark of the standard model-like fourth generation (b') on the top quark electric dipole moment. Using the known limits on the top quark electric dipole moments, we place limits on the b'…
A descriptive summary is given of the results to-date from the framed standard model (FSM) which: (i) assigns geometric meaning to the Higgs field and to fermion generations, hence offering an explanation for the observed mass and mixing…
In this work we carry out an exhaustive study to find quark mass matrices in the Standard Model~(SM), with the maximum number of texture zeros consistent with the experimental data. We found four viable configurations of five texture zeros…
Under the hypothesis that the CP violating phase parameter \delta in the CKM matrix V takes own value so that the radius R(\delta) of the circle circumscribed about the unitary triangle takes its minimum value, possible phase conventions of…
A preliminary determination of the Dirac phase in the PMNS matrix is $\dell\approx -\frac{\pi}{2}$. A rather accurately determined Jarlskog invariant $J$ in the CKM matrix is close to the maximum. Since the phases in the CKM and PMNS…
The CKM and PMNS matrices have been constructed based on the latest measurements, largely free from theoretical inputs as well as likely NP effects in the case of the former. To facilitate the construction of the CKM matrix in the PDG…