EXPERIMENTAL DETERMINATION OF THE QUARK MIXING ANGLES

1991 ◽  
Vol 06 (18) ◽  
pp. 3293-3320 ◽  
Author(s):  
G. LÓPEZ CASTRO
Keyword(s):  
Experimental Data ◽  
Symmetry Breaking ◽  
Current Status ◽  
Flavor Symmetry ◽  
Matrix Elements ◽  
Mixing Angles ◽  
Decay Properties ◽  
Quark Mixing ◽  
Exclusive Decay

We review the current status of the determination of the quark mixing angles |Vqq′|, where q=u, c; q′=d, s, b. We consider essentially exclusive decay processes, taking into account the main sources of uncertainties, the available calculations of flavor symmetry breaking for hadronic matrix elements and the possibilities of improvement offered by new experimental results. In some cases we provide full expressions for |Vqq′| in terms of measurable decay properties, which can be useful for new experimental data. Finally, we discuss briefly the effects on the unitarity tests of the Cabibbo-Kobayashi-Maskawa matrix when we consider recent corrections to the determination of |Vud|.

scholarly journals BARYONS AS THREE-FLAVOR SOLITONS

1996 ◽  
Vol 11 (14) ◽  
pp. 2419-2544 ◽  
Author(s):  
HERBERT WEIGEL
Keyword(s):  
Symmetry Breaking ◽  
Vector Meson ◽  
Degrees Of Freedom ◽  
Magnetic Moments ◽  
Axial Vector ◽  
Vector Current ◽  
Bound State ◽  
Axial Vector Current ◽  
Flavor Symmetry ◽  
Matrix Elements

The description of baryons as soliton solutions of effective meson theories for three-flavor (up, down and strange) degrees of freedom is reviewed and the phenomenological implications are illuminated. In the collective approach the soliton configuration is equipped with baryon quantum numbers by canonical quantization of the coordinates describing the flavor orientation. The baryon spectrum resulting from exact diagonalization of the collective Hamiltonian is discussed. The prediction of static properties, such as the baryon magnetic moments and the Cabibbo matrix elements for semileptonic hyperon decays, are explored with regard to the influence of flavor symmetry breaking. In particular, the role of strange degrees of freedom in the nucleon is investigated for both the vector and axial vector current matrix elements. The latter are discussed extensively within the context of the proton spin puzzle. The influence of flavor symmetry breaking on the shape of the soliton is examined, and observed to cause significant deviations from flavor-covariant predictions on the baryon magnetic moments. Short range effects are incorporated by a chirally invariant inclusion of vector meson fields. These extensions are necessary for properly describing the singlet axial vector current and the neutron–proton mass difference. The effects of the vector meson excitations on baryon properties are also considered. The bound state description of hyperons and its generalization to baryons containing a heavy quark are illustrated. In the case of the Skyrme model a comparison is made between the collective quantization scheme and the bound state approach. Finally, the Nambu–Jona-Lasinio model is employed to demonstrate that hyperons can be described as solitons in a microscopic theory of the quark flavor dynamics. This is explained for both the collective and the bound state approaches to strangeness.

WHAT DOES μ - τ SYMMETRY IMPLY ABOUT LEPTONIC CP VIOLATION?

2007 ◽  
Vol 16 (05) ◽  
pp. 1373-1381 ◽  
Author(s):  
TEPPEI BABA
Keyword(s):  
Experimental Data ◽  
Cp Violation ◽  
Symmetry Breaking ◽  
Neutrino Mass ◽  
Mass Matrix ◽  
Mass Difference ◽  
Atmospheric Neutrino ◽  
Symmetric Part ◽  
Neutrino Mixing ◽  
Mixing Angles

The μ - τ symmetry can reproduce the consistent results with experimental data of θ13, and θ23 (θ13, and θ23 respectively denote the νe - ντ, and νμ - ντ, mixing angles). However, we can not address the issue of the leptonic CP violation in μ - τ symmetric models. So we add the μ - τ symmetry breaking part to include the CP violation. We characterize leptonic CP violation in terms of three phases, where one is conventional phase δ and others are additional phases ρ and γ. These δ, ρ and γ are, respectively, the phases of νe - ντ, νe - νμ and νμ - ντ mixings. The ρ and γ are redundant but the effect of ρ remains in the leptonic CP violation which is characterized by δ + ρ. The δ arises from the μ - τ symmetry breaking part of the Meμ and Meτ while ρ arises from of μ - τ symmetric part of the Meμ and Meτ, where Mij stands for ij (i,j = e,μ,τ) element of M(= [Formula: see text] for Mν being a flavor neutrino mass matrix). Moreover, θ23 can be exactly estimated to be: [Formula: see text] ( sin θ ∝ sin θ13 cos (δ + ρ)[Formula: see text], sin ϕ ∝ Mμμ - Mττ, where [Formula: see text] is the solar neutrino mass difference squared). The conditions of maximal atmospheric neutrino mixing are given by [Formula: see text] and Mμμ = Mττ,which indicate maximal Dirac CP violation.

scholarly journals Patterns of flavor symmetry breaking in hadron matrix elements involving u , d , and s quarks

2019 ◽  
Vol 100 (11) ◽  
Author(s):  
J. M. Bickerton ◽  
R. Horsley ◽  
Y. Nakamura ◽  
H. Perlt ◽  
D. Pleiter ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Flavor Symmetry ◽  
Matrix Elements ◽  
S Quarks

scholarly journals On the CP Violation Phase in a Neutrino Mixing Model with an A4 Flavor Symmetry

2016 ◽  
Vol 26 (1) ◽  
pp. 1
Author(s):  
Phi Quang Van ◽  
Nguyen Thi Hong Van
Keyword(s):  
Experimental Data ◽  
Cp Violation ◽  
Standard Model ◽  
Mixing Model ◽  
Neutrino Masses ◽  
Flavor Symmetry ◽  
Neutrino Mixing ◽  
Normal Ordering ◽  
Mixing Angles ◽  
Mixing Matrix

Neutrino masses and mixing in an extended standard model acquiring an A4 flavour symmetry are considered. The corresponding three-neutrino mixing matrix obtained via a pertur- bative method allows us to determine the Dirac CP violation phase (\delta_{CP}) as a function of the mixing angles (\theta_{12}, \theta_{23}, \theta_{13}). Then, numerical values and distributions of \delta_{CP} are given. The latter values are quite close to the global fits of the experimental data for both the normal ordering and inverse ordering of the neutrino masses.

scholarly journals DETERMINATION OF THE CKM MATRIX ELEMENTS |Vxb|

2013 ◽  
Vol 28 (21) ◽  
pp. 1330016 ◽  
Author(s):  
GIULIA RICCIARDI
Keyword(s):  
Current Status ◽  
Matrix Elements ◽  
Ckm Matrix ◽  
The Matrix ◽  
The Absolute ◽  
Ckm Matrix Elements

We review the current status of |Vcb|, |Vub| and |Vtb|, the absolute values of the matrix elements in the CKM third column.

scholarly journals Long-Baseline Oscillation Experiments as a Tool to Probe High Energy Flavor Symmetry Models

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Pedro Pasquini
Keyword(s):  
Precision Measurement ◽  
High Energy Physics ◽  
Previous Analysis ◽  
High Energy ◽  
Current Status ◽  
Flavor Symmetry ◽  
Mixing Angles ◽  
Long Baseline ◽  
Neutrino Mass Models ◽  
Energy Physics

We review the current status of neutrino oscillation experiments, mainly focusing on T2(H)K, NOνA, and DUNE. Their capability to probe high energy physics is found in the precision measurement of the CP phase and θ23. In general, neutrino mass models predict correlations among the mixing angles that can be used to scan and shrink their parameter space. We updated previous analysis and presented a list of models that contain such structure.

Sign in / Sign up

Export Citation Format

Share Document