scholarly journals QUARK MIXING AND CP VIOLATION — THE CKM MATRIX

2006 ◽  
Vol 21 (08n09) ◽  
pp. 1724-1737 ◽  
Author(s):  
ULRICH NIERSTE
Keyword(s):  
Neutral Current ◽  
New Physics ◽  
Tree Level ◽  
B Decays ◽  
Ckm Matrix ◽  
Penguin Decays ◽  
The Status ◽  
First Results ◽  
Global Fit

I summarize the theoretical progress in the determination of the CKM elements since Lepton-Photon 2003 and present the status of the elements and parameters of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. One finds |Vus| = 0.2227 ± 0.0017 from K and τ decays and |Vcb| = (41.6 ± 0.5) · 10-3 from inclusive semileptonic B decays. The unitarity triangle can now be determined from tree-level quantities alone and the result agrees well with the global fit including flavour-changing neutral current (FCNC) processes, which are sensitive to new physics. From the global fit one finds the three CKM angles θ12 = 12.9° ± 0.1°, θ23 = 2.38° ± 0.03° and θ13 = 0.223° ± 0.007° in the standard PDG convention. The CP phase equals [Formula: see text] at 1σ CL and [Formula: see text] at 2σ CL. A major progress are first results from fully unquenched lattice QCD computations for the hadronic quantities entering the UT fit. I further present the calculation of three-loop QCD corrections to the charm contribution in [Formula: see text] decays, which removes the last relevant theoretical uncertainty from the [Formula: see text] system. Finally I discuss mixing-induced CP asymmetries in [Formula: see text] penguin decays, whose naive average is below its Standard Model value by 3σ.

scholarly journals HFLAV $τ$ branching fractions fit and measurements of Vus with $τ$ lepton data

2019 ◽  
Author(s):  
Alberto Lusiani
Keyword(s):  
Matrix Element ◽  
Branching Fraction ◽  
Branching Fractions ◽  
Final States ◽  
Ckm Matrix ◽  
The Status ◽  
Global Fit

We report the status of the Heavy Flavour Averaging Group (HFLAV) averages of the \tauτ lepton measurements We then update the latest published HFLAV global fit of the \tauτ lepton branching fractions (Spring 2017) with recent results by . We use the fit results to update the Cabibbo-Kobayashi-Maskawa (CKM) matrix element \left|V_{us}\right||Vus| measurements with the \tauτ branching fractions. We combine the direct \tauτ branching fraction measurements with indirect predictions using kaon branching fractions measurements to improve the determination of \left|V_{us}\right||Vus| using \tauτ branching fractions. The \left|V_{us}\right||Vus| determinations based on the inclusive branching fraction of \tauτ to strange final states are about 3\sigma3σ lower than the \left|V_{us}\right||Vus| determination from the CKM matrix unitarity.

scholarly journals THE CKM MATRIX AND CP VIOLATION

2005 ◽  
Vol 20 (22) ◽  
pp. 5105-5118 ◽  
Author(s):  
ZOLTAN LIGETI
Keyword(s):  
Cp Violation ◽  
New Physics ◽  
Vector Mesons ◽  
B Decays ◽  
Ckm Matrix ◽  
Charmless B Decays ◽  
The Status ◽  
Recent Developments ◽  
Nonleptonic Decays ◽  
Cp Asymmetries

The status of CP violation and the CKM matrix is reviewed. Direct CP violation in B decay has been established and the measurement of sin 2β in ψK modes reached 5% accuracy. I discuss the implications of these, and of the possible deviations of the CP asymmetries in b → s modes from that in ψK. The first meaningful measurements of α and γ are explained, together with their significance for constraining both the SM and new physics in [Formula: see text] mixing. I also discuss implications of recent developments in the theory of nonleptonic decays for B → πK rates and CP asymmetries, and for the polarization in charmless B decays to two vector mesons.

τ LEPTON PHYSICS

1998 ◽  
Vol 13 (05) ◽  
pp. 695-739 ◽  
Author(s):  
GHITA RAHAL-CALLOT
Keyword(s):  
Neutral Current ◽  
Branching Fractions ◽  
New Physics ◽  
Precise Determination ◽  
Energy Scale ◽  
Hadronic Decay ◽  
Charged Current ◽  
Beyond The Standard Model ◽  
Decay Channels

General properties of the τ leptons are reviewed using the recent measurements of production and decay of τ leptons. The improvements in the knowledge of the τ mass and the limits on ντ mass are reported. New improved measurements of the τ polarization and asymmetries performed at LEP and SLC prove a measurement of the axial and vector part of the neutral current at the per mil level. For the leptonic charged current, no deviation from the V–A Lorentz structure of the current is observed. Improvements on the lifetime and leptonic branching fractions allow a check of the charged current universality at the 0.5% level. New hadronic decay channels have been measured, mainly those involving kaons and η mesons. A precise determination of αs at the τ mass energy scale is performed. Finally, tests of possible new physics beyond the Standard Model are discussed.

scholarly journals New physics effects in tree-level decays and the precision in the determination of the quark mixing angleγ

2015 ◽  
Vol 92 (3) ◽  
Author(s):  
Joachim Brod ◽  
Alexander Lenz ◽  
Gilberto Tetlalmatzi-Xolocotzi ◽  
Martin Wiebusch
Keyword(s):  
New Physics ◽  
Tree Level ◽  
Quark Mixing

scholarly journals CLEO RESULTS: B DECAYS

2002 ◽  
Vol 17 (22) ◽  
pp. 2951-2966 ◽  
Author(s):  
DAVID G. CASSEL
Keyword(s):  
Branching Fraction ◽  
Threshold Region ◽  
Matrix Elements ◽  
B Decays ◽  
Major Step ◽  
Model Calculations ◽  
Ckm Matrix ◽  
Cleo Collaboration ◽  
First Results ◽  
Photon Energy Spectrum

Measurements of many Standard Model constants are clouded by uncertainties in nonperturbative QCD parameters that relate measurable quantities to the underlying parton-level processes. Generally these QCD parameters have been obtained from model calculations with large uncertainties that are difficult to quantify. The CLEO Collaboration has taken a major step towards reducing these uncertainties in determining the CKM matrix elements |Vcb| and |Vub| using new measurements of the branching fraction and photon energy spectrum of b → s γ decays. This report includes: the new CLEO measurements of b → s γ decays, |Vcb|, and |Vub|; the first results from CLEO III data - studies of B → Kπ, ππ, and [Formula: see text] decays; mention of some other recent CLEO B decay results; and plans for operating CESR and CLEO in the charm threshold region.

The constraints on new physics from b → s transitions

2016 ◽  
Vol 31 (29) ◽  
pp. 1650164
Author(s):  
Zhao-Feng Ge ◽  
Tai-Fu Feng ◽  
Hai-Bin Zhang
Keyword(s):  
Experimental Data ◽  
Parameter Space ◽  
New Physics ◽  
B Decays ◽  
Global Fit ◽  
Rare B Decays

Assuming that the corrections to relevant Wilson coefficients from new physics (NP) contain the possible CP phases, we analyze the constraints on the NP corrections from the updated experimental data on rare B decays from LHCb, BABAR, and BELLE, etc. systematically. Through global fit among the theoretical evaluations and corresponding experimental observations, we find that the possible CP phases of the corrections to relevant Wilson coefficients from NP affect the allowed parameter space obviously.

scholarly journals CKM PARAMETERS AND RARE B DECAYS

2006 ◽  
Vol 21 (08n09) ◽  
pp. 1683-1696 ◽  
Author(s):  
FRANCESCO FORTI
Keyword(s):  
B Meson ◽  
New Physics ◽  
Precise Determination ◽  
Model Parameters ◽  
B Decays ◽  
Unitarity Triangle ◽  
Indirect Determination ◽  
Radiative Transitions ◽  
First Time

Measurements of the angles and sides of the unitarity triangle and of the rates of rare B meson decays are crucial for the precise determination of Standard Model parameters and are sensitive to the presence of new physics particles in the loop diagrams. In this paper the recent measurements performed in this area by BABAR and Belle will be presented. The direct measurement of the angle α is for the first time as precise as the indirect determination. The precision of the |Vub| determination has improved significantly with respect to previous measurement. New limits on B → τν decays are presented, as well as updated measurements on b → s radiative transitions and a new observation of b → dγ transition made by Belle.

scholarly journals A Mathematica package for calculation of one-loop penguins in FCNC processes

2015 ◽  
Vol 26 (04) ◽  
pp. 1550042 ◽  
Author(s):  
Alexander Vadimovich Bednyakov ◽  
Şükrü Hanif Tanyıldızı
Keyword(s):  
Neutral Current ◽  
New Physics ◽  
Feynman Diagrams ◽  
Tree Level ◽  
Flavor Changing ◽  
Flavor Changing Neutral Current ◽  
Physics Model ◽  
The One ◽  
Effective Operators

In this work, we present a Mathematica package Peng4BSM@LO which calculates the contributions to the Wilson Coefficients of certain effective operators originating from the one-loop penguin Feynman diagrams. Both vector and scalar external legs are considered. The key feature of our package is the ability to find the corresponding expressions in almost any New Physics model which extends the SM and has no flavor changing neutral current (FCNC) transitions at the tree level.

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