scholarly journals A NEW APPROACH TO THE PARAMETRIZATION OF THE CABIBBO–KOBAYASHI–MASKAWA MATRIX

2001 ◽  
Vol 16 (09) ◽  
pp. 1645-1652 ◽  
Author(s):  
V. GUPTA

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 unitary and therefore can depend at most on four real parameters. The available data on the CKM-matrix including CP-violation can be reproduced by [Formula: see text]. This is also true for the special case when U depends on only 2 real parameters. Also, for such a V the invariant phase Φ≡ϕ12+ϕ23-ϕ13, satisfies a criterion suggested for "maximal" CP-violation.

2003 ◽  
Vol 18 (26) ◽  
pp. 1825-1834 ◽  
Author(s):  
S. Chaturvedi ◽  
Virendra Gupta

A new approach to the parametrization of the CKM matrix, V, is considered in which V is written as a linear combination of the unit matrix I and a nondiagonal matrix U which causes inter-generational-mixing, that is V = cos θ I + i sin θ U. Such a V depends on three real parameters including the parameter θ. It is interesting that a value of θ = π/4 is required to fit the available data on the CKM-matrix including CP-violation. Predictions of this fit for the angles α, β and γ for the unitarity triangle corresponding to [Formula: see text], are given. For θ = π/4, we obtain α = 88.46°, β = 45.046° and γ = 46.5°. These values are just about in agreement, within errors, with the present data. It is very interesting that the unitarity triangle is expected to be approximately a right-angle, isosceles triangle. Our prediction sin 2β = 1 is in excellent agreement with the value 0.99 ± 0.15 ± 0.05 reported by the Belle collaboration at the Lepton–Photon 2001 meeting.


1994 ◽  
Vol 09 (26) ◽  
pp. 2461-2467 ◽  
Author(s):  
P.S. GILL ◽  
MANMOHAN GUPTA

Fritzsch-like Hermitian quark mass matrices with decoupled u quark as well as nonzero 22-elements, both in ‘U’ and ‘D’ sectors, have been considered to reconcile the data regarding [Formula: see text] and CKM matrix elements. Exploiting the idea of maximality of CP-violation, we find two interesting relations between CKM matrix elements, viz. |Vtd|≅ |Vus||Vcb|, |Vub|≅ ½(ms/ mb)|Vus|. Apart from obtaining 0.05≤|Vub/Vcb|≤0.12 and [Formula: see text], we find CP-violating rephasing invariant parameter |J|≅(3–5)×10−5. The predicted |Vtd| value implies almost maximal mixing in [Formula: see text] system.


2004 ◽  
Vol 19 (07) ◽  
pp. 1004-1016 ◽  
Author(s):  
K. R. SCHUBERT

The present status of experimental results for the magnitudes of Cabibbo-Kobayashi-Maskawa matrix elements is reviewed and used for a unitarity test. The matrix is found to be unitary within ±1.8 standard deviations. The matrix violates CP-symmetry and the size of its CP-violation, as derived from only magnitude measurements and unitarity, is in perfect agreement with the observed CP-violations in K and B meson decays.


2017 ◽  
Vol 32 (25) ◽  
pp. 1750151 ◽  
Author(s):  
Rohit Verma

In the light of several recent analyses pointing toward texture 4-zero Fritzsch-like quark mass matrices as the only viable structures for quark mass matrices, this work adopts a model independent approach to reconstruct an alternate and simplified structure of texture specific quark mass matrices in a generalized “[Formula: see text]-diagonal” basis within the Standard Model framework using the unitarity of CKM matrix and the observed hierarchies in quark mass spectra and mixing angles. It is observed that the measured [Formula: see text] values of the three physical parameters namely [Formula: see text], [Formula: see text] and [Formula: see text] naturally lead to the vanishing of (11) element in the down type quark mass matrix and that the single measurable CP violating phase [Formula: see text] in the CKM matrix is sufficient enough in [Formula: see text] to explain the observed mixing pattern in a suitable basis. The leading order as well as exact analytic phenomenological solutions are addressed for the modest pattern of quark mass matrices derived from CKM matrix and precision measurements of mixing parameters.


2015 ◽  
Vol 30 (19) ◽  
pp. 1530014 ◽  
Author(s):  
Martin Spinrath

We discuss a possible solution to the strong CP problem which is based on spontaneous CP violation and discrete symmetries. At the same time we predict in a simple way the almost right-angled quark unitarity triangle angle [Formula: see text] by making the entries of the quark mass matrices either real or imaginary. To prove the viability of our strategy we present a toy flavour model for the quark sector.


1991 ◽  
Vol 06 (26) ◽  
pp. 4753-4762
Author(s):  
KRISHNANATH BANDYOPADHYAY ◽  
DEBASIS BHOWMICK ◽  
MURARI MOHAN KUNDU ◽  
ASIM K. RAY

We have studied the quark-mass matrices, Cabibbo mixing and CP violation in the two-generation SU(2)L × SU(2)R × U(I)B−L × U(1)H model. It is shown that the model leads to phenomenologically consistent quark-mass matrices but cannot accommodate CP violation in spite of the right-handed and horizontal gauge interactions. The absence of Cabibbo mixing for leptons is explained, but for the quark sector it is shown to be ≃0.21.


1997 ◽  
Vol 12 (35) ◽  
pp. 2655-2664 ◽  
Author(s):  
Yoshio Koide

It is pointed out that the phase convention of the CKM matrix V affects texture analysis of the quark mass matrices (Mu,Md) when we try to describe (Mu,Md) by the observable quantities (quark masses and CKM matrix parameters) only. This is demonstrated for a case of non-Hermitian Fritzsch-type mass matrix [Formula: see text], which is a general expression of quark mass matrix (Mu,Md) and is described by 12 parameters. We find that we can always choose a phase convention of V which yields [Formula: see text], so that the remaining ten parameters in [Formula: see text], can be completely expressed by the ten observable quantities.


1991 ◽  
Vol 06 (24) ◽  
pp. 2243-2247 ◽  
Author(s):  
DANIEL NG ◽  
Y. JACK NG

A simple ansatz for quark mass matrices which yields the Kac–Moody (KM) matrix elements, [Formula: see text], Vcb = ms/mb, and [Formula: see text], is investigated, resulting in two empirical identities, md/ms = ms/mb and mu/mc = mc/mt. Using Vub = 0.004 ± 0.002, we obtain mt = (290 ± 140) GeV . We find that this prediction is consistent with other processes, such as [Formula: see text] mixing. The invariant quantity, J, of CP violation is of the order 3 × 10−5 in agreement with experiments.


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