Simple quark mass matrices and mixing

1993 ◽  
Vol 71 (3-4) ◽  
pp. 172-174
Author(s):  
B. Margolis ◽  
S. Punch

We present mass matrices identical in form for both the up and down quark families, with the following remarkable properties. Both up and down quark masses, at a scale of 1 GeV, are well-approximated by geometric progressions. The five known quark masses and the Kobayashi–Maskawa (KM) mixing matrix agree with experiment. The KM matrix is expressed in terms of only two parameters. We give the KM matrix in the Wolfenstein form.

1992 ◽  
Vol 07 (25) ◽  
pp. 6357-6370 ◽  
Author(s):  
ROBERT E. SHROCK

We study an ansatz for the quark mass matrix in which all of the nondiagonal entries are nonzero, but which still allows the quark mixing angles to be calculated in terms of ratios of quark masses and certain phases. Analytic calculations of the orthogonal rotation matrices in the up and down quark sectors and the resultant observed quark mixing matrix are presented. Comparison with experimental data is given.


1997 ◽  
Vol 12 (08) ◽  
pp. 561-571 ◽  
Author(s):  
Tatsuo Kobayashi ◽  
Zhi-Zhong Xing

We propose a simple but realistic pattern of quark mass matrices at the string scale, which can be derived from orbifold models of superstring theory with no use of gauge symmetries. This pattern is left–right symmetric and preserves the structural parallelism between up and down quark sectors. Its phenomenological consequences on flavor mixing and CP-violation are confronted with current experiments at the weak scale by using the renormalization group equations in the framework of minimal supersymmetric standard model. We find that good agreement is achievable without fine-tuning.


2018 ◽  
Vol 33 (39) ◽  
pp. 1850230
Author(s):  
Yoshio Koide ◽  
Hiroyuki Nishiura

Recently, we have proposed a quark mass matrix model based on U(3) × U(3)[Formula: see text] family symmetry, in which up- and down-quark mass matrices [Formula: see text] and [Formula: see text] are described only by complex parameters [Formula: see text] and [Formula: see text], respectively. When we use charged lepton masses as additional input values, we can successfully obtain predictions for quark masses and Cabibbo–Kobayashi–Maskawa mixing. Since we have only one complex parameter [Formula: see text] for each mass matrix [Formula: see text], we can obtain a parameter-independent mass relation by using three equations for [Formula: see text], [Formula: see text] and [Formula: see text], where [Formula: see text] ([Formula: see text]). In this paper, we investigate the parameter-independent feature of the quark mass relation in the model.


2012 ◽  
Vol 27 (06) ◽  
pp. 1250026
Author(s):  
S. CHATURVEDI ◽  
V. GUPTA ◽  
G. SÁNCHEZ-COLÓN ◽  
S. RAJPOOT

Using the four best measured moduli of the flavor mixing matrix (|V ud |, |V us |, |V cd |, |V cs |), the Jarlskog invariant J(V), and the quark masses at MZ energy scale as experimental constraints, a statistical comparison of three different types of quark mass matrices in the physical basis is performed. The mass matrices in question are the Chaturvedi–Gupta–Sánchez-Colón (CGS), the Fritzsch and the Gupta–Rajpoot types. With nine parameters the best fits are obtained using a Gupta–Rajpoot-type matrix while with seven parameters the best fits are obtained using the CGS-type matrix. The stability of our analysis with respect to evolution of the quark masses is also presented.


2002 ◽  
Vol 17 (10) ◽  
pp. 627-630 ◽  
Author(s):  
ERNEST MA

If the standard model of quark interactions is supplemented by a discrete A4 symmetry (which may be relevant for the lepton sector), the spontaneous breaking of the electroweak gauge symmetry allows arbitrary quark masses, but all mixing angles are predicted to be zero. A pattern of the explicit breaking of A4 is proposed, which results in a realistic charged-current mixing matrix.


2005 ◽  
Vol 20 (06) ◽  
pp. 1234-1243 ◽  
Author(s):  
P. RAMOND

We relate the MNS and CKM mixing matrices using ideas from grand unification. We catalog models in terms of the family symmetries of the down quark mass matrices, and emphasize the role of the Cabibbo angle in the lepton mixing matrix. We find a large class of models with an observable CHOOZ angle [Formula: see text].


Author(s):  
Steven E. Vigdor

Chapter 4 deals with the stability of the proton, hence of hydrogen, and how to reconcile that stability with the baryon number nonconservation (or baryon conservation) needed to establish a matter–antimatter imbalance in the infant universe. Sakharov’s three conditions for establishing a matter–antimatter imbalance are presented. Grand unified theories and experimental searches for proton decay are described. The concept of spontaneous symmetry breaking is introduced in describing the electroweak phase transition in the infant universe. That transition is treated as the potential site for introducing the imbalance between quarks and antiquarks, via either baryogenesis or leptogenesis models. The up–down quark mass difference is presented as essential for providing the stability of hydrogen and of the deuteron, which serves as a crucial stepping stone in stellar hydrogen-burning reactions that generate the energy and elements needed for life. Constraints on quark masses from lattice QCD calculations and violations of chiral symmetry are discussed.


2005 ◽  
Vol 20 (16) ◽  
pp. 1217-1225 ◽  
Author(s):  
LUÍS LAVOURA ◽  
ERNEST MA

We propose two simple models for the quark mass matrices which may be implemented through an S3×Z2 symmetry in a supersymmetric context. Each model has eight parameters and, therefore, makes two independent predictions for the quark mixing matrix. The first model predicts [Formula: see text] and [Formula: see text]. The second model, in which the forms of the up-type-quark and down-type-quark mass matrices are interchanged relative to the first one, predicts |Vub/Vcb|~0.11 and |Vtd/Vts|~0.33. Both models have sin 2β~0.5.


2007 ◽  
Vol 16 (05) ◽  
pp. 1383-1393 ◽  
Author(s):  
HIDEYUKI SAWANAKA

Realistic quark masses and mixing angles are obtained applying the successful A4 family symmetry for leptons, motivated by the quark-lepton assignments of SU (5). The A4 symmetry is suitable to give tri-bimaximal neutrino mixing matrix which is consistent with current experimental data. We study new scenario for the quark sector with the A4 symmetry.


1991 ◽  
Vol 06 (23) ◽  
pp. 2169-2172 ◽  
Author(s):  
PAUL H. FRAMPTON ◽  
YASUHIRO OKADA

A new formula relating flavor mixing and quark masses is derived from an ansatz for mass matrices. In particular, given mu, mc and |Vcb| the formula relates the top mass mt to |Vub|.


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