scholarly journals Minimal texture of quark mass matrices and precision CKM measurements

Author(s):  
Shivali Kaundal ◽  
Aakriti Bagai ◽  
Gulsheen Ahuja ◽  
Manmohan Gupta

Abstract We have carried out an extensive analysis of all possible minimal texture quark mass matrices implying 169 texture-6 zero combinations. One finds that all these combinations are ruled out: a good number of these analytically, the other possibilities being excluded by the present quark mixing data. Interestingly, even if there are future changes in the ranges of the light quark masses, these conclusions remain valid.

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Aakriti Bagai ◽  
Shivali Kaundal ◽  
Gulsheen Ahuja ◽  
Manmohan Gupta

Abstract An attempt has been made to carry out a detailed analysis of quark mass matrices having structure beyond the minimal texture. In particular, keeping in mind precision measurements of Cabibbo–Kobayashi–Maskawa parameters as well as refinements in the ranges of light quark masses, we have examined the viability of all possible combinations of Hermitian texture 5 zero quark mass matrices. Interestingly, one finds that all these possibilities are now excluded by the present quark mixing data, thereby having important implications for model building.


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.


2018 ◽  
Vol 175 ◽  
pp. 14017 ◽  
Author(s):  
Julien Frison ◽  
Ryuichiro Kitano ◽  
Norikazu Yamada

One of the historical suggestions to tackle the strong CP problem is to take the up quark mass to zero while keeping md finite. The θ angle is then supposed to become irrelevant, i.e. the topological susceptibility vanishes. However, the definition of the quark mass is scheme-dependent and identifying the mu = 0 point is not trivial, in particular with Wilson-like fermions. More specifically, up to our knowledge there is no theoretical argument guaranteeing that the topological susceptibility exactly vanishes when the PCAC mass does. We will present our recent progresses on the empirical check of this property using Nf = 1 + 2 flavours of clover fermions, where the lightest fermion is tuned very close to [see formula in PDF] and the mass of the other two is kept of the order of magnitude of the physical ms. This choice is indeed expected to amplify any unknown non-perturbative effect caused by mu ≠ md. The simulation is repeated for several βs and those results, although preliminary, give a hint about what happens in the continuum limit.


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.


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.


2013 ◽  
Vol 28 (26) ◽  
pp. 1360016 ◽  
Author(s):  
KARL SCHILCHER

Recent QCD sum rule determinations of the light quark masses are reviewed. In the case of the strange quark mass, possible uncertainties are discussed in the framework of finite energy sum rules.


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.


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|.


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.


2018 ◽  
Vol 175 ◽  
pp. 06002 ◽  
Author(s):  
Davide Giusti ◽  
Vittorio Lubicz ◽  
Guido Martinelli ◽  
Francesco Sanfilippo ◽  
Silvano Simula ◽  
...  

We present a study of the isospin-breaking (IB) corrections to pseudoscalar (PS) meson masses using the gauge configurations produced by the ETM Collaboration with Nf = 2+1+1 dynamical quarks at three lattice spacings varying from 0.089 to 0.062 fm. Our method is based on a combined expansion of the path integral in powers of the small parameters [see formula in PDF] and αem, where [see formula in PDF] is the renormalized quark mass and αem the renormalized fine structure constant. We obtain results for the pion, kaon and Dmeson mass splitting; for the Dashen’s theorem violation parameters ϵγ(MM, 2 GeV), ϵπ0 ϵK0(MS, 2 GeV) for the light quark masses [see formula in PDF] for the flavour symmetry breaking parameters R(MS, 2 GeV) and Q(MS, 2 GeV) and for the strong IB effects on the kaon decay constants.


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