CKM MATRIX ELEMENT MAGNITUDES

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.

2005 ◽  
Vol 20 (02n03) ◽  
pp. 385-398
Author(s):  
KLAUS R. SCHUBERT

After a short introduction on CP asymmetries in K and B meson decays, I discuss a few recent results related to CP violation, mainly from the BABAR experiment: CPT tests in [Formula: see text] mixing, search for CP violation in [Formula: see text] and [Formula: see text] decays, and measurements of the unitarity-triangle angle α in B →ππ and B →ρρ decays. I conclude with the result of a CKM-matrix fit to all relevant observations.


1995 ◽  
Vol 10 (02) ◽  
pp. 165-172 ◽  
Author(s):  
KARL BERKELMAN

The favored tests of CP violation in B meson decays give sin 2α and sin 2β, where α and β are angles in the unitarity triangle relating the Kobayashi–Maskawa matrix elements. In the classic B Factory experiment sin 2α or sin 2β is obtained by observing a time dependent CP violating asymmetry in the decay of tagged B0, [Formula: see text] pairs, mediated by [Formula: see text] mixing. The same measurement can be performed at a symmetric energy collider operating at the ϒ (4S) resonance, given sufficient luminosity and vertex resolution. That is, provided the vertical spread of the beam at the interaction point is small, for two-event subclasses the centroid separation in measurements of the observed midpoint between the heights of the two decay vertices is a good statistical estimator for the CP violation parameter sin 2α or sin 2β. With a typical detector the number of events needed is about three times what an asymmetric B Factory would require for the same accuracy.


2005 ◽  
Vol 20 (16) ◽  
pp. 3707-3711
Author(s):  
◽  
JOCHEN DINGFELDER

Measurements of charmless semileptonic B-meson decays and the CKM matrix element |Vub| are reported based on a sample of 88 million [Formula: see text] events recorded with the BABAR detector. Decays B → Xuℓν are selected from both tagged and untagged [Formula: see text] events and separated from the dominant charm background, B → Xcℓν, using different kinematic variables: the lepton momentum Eℓ, the squared four-momentum transfer q2, and the hadronic mass mX. The extrapolation to the total decay rate to determine |Vub| is performed for different theoretical models. We have also measured branching ratios for the exclusive semileptonic decays B → π(ρ,ω,η,η′,a0)ℓν, where a high signal purity is reached by fully or partially reconstructing the second B meson.


2008 ◽  
Vol 23 (31) ◽  
pp. 4945-4958 ◽  
Author(s):  
FRANCESCA DI LODOVICO

Flavour mixing is described within the Standard Model by the Cabibbo–Kobayashi–Maskawa (CKM) matrix elements. With the increasingly higher statistics collected by many experiments, the matrix elements are measured with improved precision, allowing for more stringent tests of the Standard Model. In this paper, a review of the current status of the absolute values of the CKM matrix elements is presented, with particular attention to the latest measurements.


1997 ◽  
Vol 12 (37) ◽  
pp. 2873-2882 ◽  
Author(s):  
H. Routh ◽  
V. P. Gautam

In our letter we deal with the inclusive and exclusive decay of B- meson. The inclusive b→dγ decay has been considered here including the QCD corrections to the Wilson coefficients and the matrix elements of the operators in the effective Hamiltonian. We calculate the O(αs) virtual corrections to the matrix element for b→dγ, taking into account the contributions of the four-fermion operator O2 and the electromagnetic and color dipole type operators. It drastically reduces the large scale dependence of the leading logarithmic approximation. Moreover, while we are considering the exclusive B-→ρ-γ decay, we have taken into consideration both the short distance as well as long distance contributions. Therefore, we have obtained better result for the partial decay width of B-→ρ-γ.


2007 ◽  
Vol 22 (02n03) ◽  
pp. 274-281
Author(s):  
◽  
TAKEO KAWASAKI

The Belle experiment has started in 1999 and has collected more than 600 fb-1 data at the ϒ(4S) resonance with the KEK-B asymmetric energy e+e- collider. In this contribution, the results of CP-violation measurement in B meson decays are presented. The large CP asymmetry arises thorough the interference between [Formula: see text] mixing and decay. The results yield constraints on the angles of the unitarity triangle, which is related to the Kobayashi-Maskawa quark mixing matrix. We discuss the status of the measurements on ϕ1, ϕ2 and ϕ3 with various methods.


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.


2004 ◽  
Vol 19 (12) ◽  
pp. 921-925 ◽  
Author(s):  
A. BHATTACHARYA ◽  
S. N. BANERJEE ◽  
B. CHAKRABARTI ◽  
S. BANERJEE

The ratios of Bd and Bs meson decay constant have been estimated using the variational method in conjunction with the relativistic Hamiltonian of the heavy meson in the framework of the statistical model. The ratio of CKM matrix elements [Formula: see text] has been extracted from [Formula: see text] mixing using the estimated decay constants and ratio of Bd and Bs mass differences. The results are found to be in good agreement with the existing theoretical and experimental predictions.


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