Semileptonic decays of D, B, K mesons and the full CKM matrix from unquenched lattice QCD

2005 ◽  
Vol 20 (15) ◽  
pp. 3469-3475 ◽  
Author(s):  
◽  
Masataka Okamoto

We use lattice QCD to fully determine the CKM matrix. |Vcd|, |Vcs|, |Vub|, |Vcb| and |Vus| are, respectively, directly determined with our lattice results for form factors of semileptonic D → πlν, D → Klν, B → πlν, B → Dlν and K → πlν decays. The accuracy is comparable to that of the Particle Data Group averages. In addition, |Vud|, |Vtb|, |Vts| and |Vtd| are determined by using unitarity of the CKM matrix and the experimental result for sin (2β). In this way, we obtain all 9 CKM matrix elements, where the only theoretical input is lattice QCD.

2009 ◽  
Vol 24 (supp01) ◽  
pp. 521-567
Author(s):  
Ya-Dong Yang ◽  
Hai-Bo Li ◽  
Jia-Heng Zou ◽  
Jiang-Chuan Chen ◽  
Jian Liu ◽  
...  

The following sections are included: Leptonic Decays Semileptonic Decays Impact on CKM Measurements


2005 ◽  
Vol 20 (16) ◽  
pp. 3651-3653
Author(s):  
MATTHEW WINGATE ◽  
CHRISTINE DAVIES ◽  
ALAN GRAY ◽  
EMEL GULEZ ◽  
JUNKO SHIGEMITSU ◽  
...  

Lattice Monte Carlo simulations now include the effects of 2 light sea quarks and 1 strange sea quark through the use of an improved staggered fermion action. Consequently, results important to phenomenology are free of the approximate 10% errors inherent in the quenched approximation. This talk reports on calculations of the B and Bs, decay constants and B → πℓν form factors. Accurate determinations of these quantities will lead to tighter constraints on CKM matrix elements.


Author(s):  
ROY A. BRIERE

We first review recent measurements of D → μν and Ds → μν, τν from CLEO-c. These decays are used to determine leptonic decay constants fD and fDs which may be compared to modern Lattice QCD (LQCD) calculations. Such cross-checks can provide confidence in Lattice results for B(s) meson decay constants which are needed to fully exploit data used to extract the CKM matrix elements Vub and Vcb. We also comment briefly on the outlook for further progress at BESIII.


2005 ◽  
Vol 20 (16) ◽  
pp. 3600-3604
Author(s):  
◽  
F. Liu

Based on a data sample of 60 pb-1 collected at the ψ(3770) resonance with the CLEO-c detector at CESR, we present improved measurements of absolute branching fractions for exclusive D0 semileptonic decays into K-e+ν, π-e+ν and K*-e+ν, and the first observation and measurement of D0 → ρ-e+ν. The determinations of the CKM matrix elements Vcs and Vcd are reviewed.


Author(s):  
S. Aoki ◽  
Y. Aoki ◽  
D. Bečirević ◽  
T. Blum ◽  
G. Colangelo ◽  
...  

Abstract We review lattice results related to pion, kaon, D-meson, B-meson, and nucleon physics with the aim of making them easily accessible to the nuclear and particle physics communities. More specifically, we report on the determination of the light-quark masses, the form factor $$f_+(0)$$f+(0) arising in the semileptonic $$K \rightarrow \pi $$K→π transition at zero momentum transfer, as well as the decay constant ratio $$f_K/f_\pi $$fK/fπ and its consequences for the CKM matrix elements $$V_{us}$$Vus and $$V_{ud}$$Vud. Furthermore, we describe the results obtained on the lattice for some of the low-energy constants of $$SU(2)_L\times SU(2)_R$$SU(2)L×SU(2)R and $$SU(3)_L\times SU(3)_R$$SU(3)L×SU(3)R Chiral Perturbation Theory. We review the determination of the $$B_K$$BK parameter of neutral kaon mixing as well as the additional four B parameters that arise in theories of physics beyond the Standard Model. For the heavy-quark sector, we provide results for $$m_c$$mc and $$m_b$$mb as well as those for D- and B-meson decay constants, form factors, and mixing parameters. These are the heavy-quark quantities most relevant for the determination of CKM matrix elements and the global CKM unitarity-triangle fit. We review the status of lattice determinations of the strong coupling constant $$\alpha _s$$αs. Finally, in this review we have added a new section reviewing results for nucleon matrix elements of the axial, scalar and tensor bilinears, both isovector and flavor diagonal.


2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Ulrich Haisch ◽  
Amando Hala

Abstract We estimate the form factors that parametrise the hadronic matrix elements of proton-to-pion transitions with the help of light-cone sum rules. These form factors are relevant for semi-leptonic proton decay channels induced by baryon-number violating dimension-six operators, as typically studied in the context of grand unified theories. We calculate the form factors in a kinematical regime where the momentum transfer from the proton to the pion is space-like and extrapolate our final results to the regime that is relevant for proton decay. In this way, we obtain estimates for the form factors that show agreement with the state-of-the-art calculations in lattice QCD, if systematic uncertainties are taken into account. Our work is a first step towards calculating more involved proton decay channels where lattice QCD results are not available at present.


2014 ◽  
Vol 29 (20) ◽  
pp. 1430019 ◽  
Author(s):  
Giulia Ricciardi

We report on the current status of semi-leptonic B(s) decays, including rare decays, and the extraction of the absolute values of the CKM matrix elements |Vcb| and |Vub|.


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