scholarly journals Improvement of heavy-heavy current for calculation of B̅ → D(*)lv̅ form factors using Oktay-Kronfeld heavy quarks

2018 ◽  
Vol 175 ◽  
pp. 14010 ◽  
Author(s):  
Jon A. Bailey ◽  
Yong-Chull Jang ◽  
Weonjong Lee ◽  
Jaehoon Leem
Keyword(s):  
Matrix Element ◽  
Lattice Qcd ◽  
Heavy Quark ◽  
Recent Progress ◽  
Form Factors ◽  
Heavy Quarks ◽  
Power Counting ◽  
Ckm Matrix ◽  
Combining Data ◽  
Discretization Errors

The CKM matrix element |Vcb| can be extracted by combining data from experiments with lattice QCD results for the semileptonic form factors for the B̅ → D(*)lv̅ decays. The Oktay-Kronfeld (OK) action was designed to reduce heavy-quark discretization errors to below 1%, or through O(λ3) in HQET power counting. Here we describe recent progress on bottom-to-charm currents improved to the same order in HQET as the OK action, and correct formerly reported results of our matching calculations, in which the operator basis was incomplete.

scholarly journals B → D*lv at non-zero recoil

2018 ◽  
Vol 175 ◽  
pp. 13003 ◽  
Author(s):  
Alejandro Vaquero Avilés-Casco ◽  
Carleton DeTar ◽  
Daping Du ◽  
Aida El-Khadra ◽  
Andreas Kronfeld ◽  
...  
Keyword(s):  
Matrix Element ◽  
Decay Rate ◽  
Form Factors ◽  
Heavy Quarks ◽  
Experimental Measurements ◽  
Ckm Matrix ◽  
Preliminary Results ◽  
Future Plans

We present preliminary results from our analysis of the form factors for the B → D*lv decay at non-zero recoil. Our analysis includes 15 MILC asqtad ensembles with Nf = 2 + 1 flavors of sea quarks and lattice spacings ranging from a ≈ 0.15 fm down to 0.045 fm. The valence light quarks employ the asqtad action, whereas the heavy quarks are treated using the Fermilab action. We conclude with a discussion of future plans and phenomenological implications. When combined with experimental measurements of the decay rate, our calculation will enable a determination of the CKM matrix element |Vcb|.

scholarly journals Study of the B → Xcℓν Decays and Determination of |Vcb|

2005 ◽  
Vol 20 (16) ◽  
pp. 3644-3647
Author(s):  
◽  
Vladimir Golubev
Keyword(s):  
Matrix Element ◽  
Heavy Quark ◽  
Electron Energy ◽  
Branching Fraction ◽  
Form Factors ◽  
Ckm Matrix ◽  
Mass Distributions ◽  
Babar Detector ◽  
Decay Form

We report studies of semileptonic decays, B → Xcℓν, based on a sample of 88 million [Formula: see text] events recorded with the BABAR detector. We have measured four moments of the electron energy and hadronic mass distributions and determined the inclusive branching fraction, the CKM matrix element |Vcb|, and other heavy quark parameters, using Heavy Quark Expansions in the kinetic mass scheme. In addition, we have studied a large sample of B0 → D*-ℓ+ν decays and extracted the decay form factors and |Vcb|.

scholarly journals D → Klv semileptonic decay using lattice QCD with HISQ at physical pion masses

2018 ◽  
Vol 175 ◽  
pp. 13027 ◽  
Author(s):  
Bipasha Chakraborty ◽  
Christine Davies ◽  
Jonna Koponen ◽  
G Peter Lepage
Keyword(s):  
Standard Model ◽  
Lattice Qcd ◽  
Semileptonic Decay ◽  
Light Quark ◽  
Form Factors ◽  
New Physics ◽  
Ckm Matrix ◽  
Quark Masses ◽  
The Standard Model ◽  
Fertile Ground

he quark flavor sector of the Standard Model is a fertile ground to look for new physics effects through a unitarity test of the Cabbibo-Kobayashi-Maskawa (CKM) matrix. We present a lattice QCD calculation of the scalar and the vector form factors (over a large q2 region including q2 = 0) associated with the D→ Klv semi-leptonic decay. This calculation will then allow us to determine the central CKM matrix element, Vcs in the Standard Model, by comparing the lattice QCD results for the form factors and the experimental decay rate. This form factor calculation has been performed on the Nf = 2 + 1 + 1 MILC HISQ ensembles with the physical light quark masses.

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
Keyword(s):  
Lattice Qcd ◽  
Form Factors ◽  
Semileptonic Decays ◽  
Experimental Result ◽  
Particle Data Group ◽  
Matrix Elements ◽  
Ckm Matrix ◽  
Ckm Matrix Elements ◽  
K Mesons ◽  
Data Group

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.

scholarly journals A closer look at the extraction of |Vub| from B → πℓν

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Aritra Biswas ◽  
Soumitra Nandi ◽  
Sunando Kumar Patra ◽  
Ipsita Ray
Keyword(s):  
Matrix Element ◽  
Confidence Interval ◽  
Form Factors ◽  
Data Sets ◽  
Heavy Flavor ◽  
Comparable Group ◽  
Bayesian Approaches ◽  
Sum Rule ◽  
Ckm Matrix ◽  
Inclusive Decays

Abstract To extract the Cabibbo-Kobayashi-Maskawa (CKM) matrix element |Vub|, we have re-analyzed all the available inputs (data and theory) on the B → πℓν decays including the newly available inputs on the form-factors from light cone sum rule (LCSR) approach. We have reproduced and compared the results with the procedure taken up by the Heavy Flavor Averaging Group (HFLAV), while commenting on the effect of outliers on the fits. After removing the outliers and creating a comparable group of data-sets, we mention a few scenarios in the extraction of |Vub|. In all those scenarios, the extracted values of |Vub| are higher than that obtained by HFLAV. Our best results for |Vub|exc. are (3.94 ± 0.14) × 10−3 and $$ \left({3.93}_{-0.15}^{+0.14}\right) $$ 3.93 − 0.15 + 0.14 × 10−3 in frequentist and Bayesian approaches, respectively, which are consistent with that extracted from inclusive decays |Vub|inc. within 1 σ confidence interval.

scholarly journals Heavy Quark Expansion of Λb→Λ*(1520) Form Factors beyond Leading Order

Symmetry ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 531
Author(s):  
Marzia Bordone
Keyword(s):  
Lattice Qcd ◽  
Heavy Quark ◽  
Form Factors ◽  
Higher Order ◽  
Leading Order ◽  
Lattice Data ◽  
Tensor Form ◽  
Higher Order Terms ◽  
First Time

I review the parametrisation of the full set of Λb→Λ*(1520) form factors in the framework of Heavy Quark Expansion, including next-to-leading-order O(αs) and, for the first time, next-to-leading-power O(1/mb) corrections. The unknown hadronic parameters are obtained by performing a fit to recent lattice QCD calculations. I investigate the compatibility of the Heavy Quark Expansion and the current lattice data, finding tension between these two approaches in the case of tensor and pseudo-tensor form factors, whose origin could come from an underestimation of the current lattice QCD uncertainties and higher order terms in the Heavy Quark Expansion.

scholarly journals A MORE PRECISE EXTRACTION OF |Vcb| IN HQEFT OF QCD

2004 ◽  
Vol 19 (18) ◽  
pp. 1379-1390 ◽  
Author(s):  
W. Y. WANG ◽  
Y. L. WU ◽  
Y. A. YAN ◽  
M. ZHONG ◽  
Y. B. ZUO
Keyword(s):  
Field Theory ◽  
Experimental Data ◽  
Matrix Element ◽  
Heavy Quark ◽  
Effective Field Theory ◽  
Effective Field ◽  
Decay Rates ◽  
Recent Experimental Data ◽  
B Decays ◽  
Ckm Matrix

The more precise extraction for the CKM matrix element |Vcb| in the heavy quark effective field theory (HQEFT) of QCD is studied from both exclusive and inclusive semileptonic B decays. The values of relevant nonperturbative parameters up to order [Formula: see text] are estimated consistently in HQEFT of QCD. Using the most recent experimental data for B decay rates, |Vcb| is updated to be |Vcb|=0.0395±0.0011expt±0.0019theorfrom B→D*lν decay and |Vcb|=0.0434±0.0041expt±0.0020theorfrom B→Dlν decay as well as |Vcb|=0.0394±0.0010expt±0.0014theorfrom inclusive B→Xclν decay.

scholarly journals $B \to D^{(*)}\ell\nu$ form factors from lattice QCD with relativistic heavy quarks

2020 ◽  
Author(s):  
Takashi Kaneko ◽  
Y. Aokic ◽  
G. Bailas ◽  
B. Colquhoun ◽  
H. Fukaya ◽  
...  
Keyword(s):  
Lattice Qcd ◽  
Form Factors ◽  
Heavy Quarks

scholarly journals Recent progress on the study of nucleon structure from lattice QCD and future perspectives

2020 ◽  
Author(s):  
Constantia Alexandrou
Keyword(s):  
Lattice Qcd ◽  
Recent Progress ◽  
Form Factors ◽  
Distribution Functions ◽  
Nucleon Structure ◽  
Electromagnetic Form Factors ◽  
Momentum Fraction ◽  
Future Perspectives ◽  
Parton Distribution Functions ◽  
Quark Masses

We review the progress achieved within the last five years in the simulations of lattice QCD, as well as in the analysis for selected quantities probing nucleon structure. In particular, we discuss results on the nucleon electromagnetic form factors, \sigmaσ-terms, the momentum fraction carried by quark in the nucleon and the helicity and transversity moments. All quantities are obtained using simulations generated with quark masses fixed to their physical values. In addition, we review the on-going effort to extract parton distribution functions (PDFs) directly from lattice QCD using the quasi-PDF approach.

scholarly journals Determination of the form factors for the decayB0→D*−l+νland of the CKM matrix element|Vcb|

2008 ◽  
Vol 77 (3) ◽  
Author(s):  
B. Aubert ◽  
M. Bona ◽  
D. Boutigny ◽  
Y. Karyotakis ◽  
J. P. Lees ◽  
...  
Keyword(s):  
Matrix Element ◽  
Form Factors ◽  
Ckm Matrix
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