$B\to Kl^+l^-$ Decay Form Factors from Three-flavor Lattice QCD.

$B\to Kl^+l^-$ Decay Form Factors from Three-flavor Lattice QCD. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
We compute the form factors for the B → Kl+l- semileptonic decay process in lattice QCD using gauge-field ensembles with 2+1 flavors of sea quark, generated by the MILC Collaboration. The ensembles span lattice spacings from 0.12 to 0.045 fm and have multiple sea-quark masses to help control the chiral extrapolation. The asqtad improved staggered action is used for the light valence and sea quarks, and the clover action with the Fermilab interpretation is used for the heavy b quark. We present results for the form factors f+(q2), f0(q2), and fT(q2), where q2 is the momentum transfer, together with a comprehensive examination of systematic errors. Lattice QCD determines the form factors for a limited range of q2, and we use the model-independent z expansion to cover the whole kinematically allowed range. We present our final form-factor results as coefficients of the z expansion and the correlations between them, where the errors on the coefficients include statistical and all systematic uncertainties. Lastly, we use this complete description of the form factors to test QCD predictions of the form factors at high and low q2.

$B\to Kl^+l^-$ Decay Form Factors from Three-flavor Lattice QCD.

$B\to Kl^+l^-$ Decay Form Factors from Three-flavor Lattice QCD. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
We compute the form factors for the B → Kl+l- semileptonic decay process in lattice QCD using gauge-field ensembles with 2+1 flavors of sea quark, generated by the MILC Collaboration. The ensembles span lattice spacings from 0.12 to 0.045 fm and have multiple sea-quark masses to help control the chiral extrapolation. The asqtad improved staggered action is used for the light valence and sea quarks, and the clover action with the Fermilab interpretation is used for the heavy b quark. We present results for the form factors f+(q2), f0(q2), and fT(q2), where q2 is the momentum transfer, together with a comprehensive examination of systematic errors. Lattice QCD determines the form factors for a limited range of q2, and we use the model-independent z expansion to cover the whole kinematically allowed range. We present our final form-factor results as coefficients of the z expansion and the correlations between them, where the errors on the coefficients include statistical and all systematic uncertainties. Lastly, we use this complete description of the form factors to test QCD predictions of the form factors at high and low q2.

Form Factors for $B$ to $Kll$ Semileptonic Decay from Three-Flavor Lattice QCD.

Form Factors for $B$ to $Kll$ Semileptonic Decay from Three-Flavor Lattice QCD. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 7

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Book Description
We study the B 2!Kll− semileptonic decay process in three-flavor lattice QCD. We analyze several ensembles generated by theMILC collaboration at different lattice spacings and sea-quark masses. We use the asqtad improved staggered action for the light quarks and the clover action with the Fermilab interpretation for the heavy b quark. We present preliminary results for the vector current induced form factors for a range of kaon energies. Our analysis includes chiral and continuum extrapolations based on SU(2) staggered [chi]PT.

$B \to \pi \ell \nu$ and $B_s \to K \ell \nu$ Form Factors and $

$B \to \pi \ell \nu$ and $B_s \to K \ell \nu$ Form Factors and $ PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 38

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Book Description
We calculate the form factors for B → [pi]l[nu] and Bs → Kl[nu] decay in dynamical lattice quantum chromodynamics (QCD) using domain-wall light quarks and relativistic b-quarks. We use the (2+1)-flavor gauge-field ensembles generated by the RBC and UKQCD collaborations with the domain-wall fermion action and Iwasaki gauge action. For the b-quarks we use the anisotropic clover action with a relativistic heavy-quark interpretation. We analyze data at two lattice spacings of a ≈ 0.11, 0.086 fm with unitary pion masses as light as M[pi] ≈ 290 MeV. We simultaneously extrapolate our numerical results to the physical light-quark masses and to the continuum and interpolate in the pion/kaon energy using SU(2) "hard-pion" chiral perturbation theory for heavy-light meson form factors. We provide complete systematic error budgets for the vector and scalar form factors f + (q2) and f0(q2) for both B → [pi]l[nu] and Bs → Kl[nu] at three momenta that span the q2 range accessible in our numerical simulations. Next we extrapolate these results to q2 = 0 using a model-independent z-parametrization based on analyticity and unitarity. We present our final results for f+(q2) and f0(q2)as the coefficients of the series in z and the matrix of correlations between them; this provides a parametrization of the form factors valid over the entire allowed kinematic range. Our results agree with other three-flavor lattice-QCD determinations using staggered light quarks, and have comparable precision, thereby providing important independent cross-checks. Both B → [pi]l[nu] and Bs → Kl[nu] decays enable determinations of the Cabibbo-Kobayashi-Maskawa matrix element.

16th Conference on Flavor Physics and CP Violation

16th Conference on Flavor Physics and CP Violation PDF Author: Anjan Giri
Publisher: Springer Nature
ISBN: 3030296229
Category : Science
Languages : en
Pages : 493

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Book Description
Presenting the proceedings of FPCP 2018, this book reviews the status quo of flavor physics and discusses the latest findings in this exciting area. Flavor physics has been instrumental in the formulation and understanding of the standard model, and it is possible that the direction of new physics will be significantly influenced by flavor sector, also known as the intensity frontier, making it possible to indirectly test the existence of new physics up to a very high scale, beyond that of the energy frontier scale accessible at the LHC. The book is intended for academics around the globe involved in particle physics research, professionals associated with the related technologies and those who are interested in learning about the future of physics and its prospects and directions.

Gauge Theory of Weak Decays

Gauge Theory of Weak Decays PDF Author: Andrzej J. Buras
Publisher: Cambridge University Press
ISBN: 1107034035
Category : Science
Languages : en
Pages : 739

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Book Description
"The ultimate question of elementary particle physics is: What is the fundamental Lagrangian of nature surrounding us? The Lagrangian of the SM is very successful in describing nature at the currently available energy range. The discovery of the Higgs boson completed the particle spectrum of the SM and it is another proof of how well the SM works. Nevertheless the SM cannot be the end of the story and it is for sure not the fundamental Lagrangian of nature. The Lagrangian of the SM looses its validity at the latest at the Planck scale where gravitational effects become noticeable.Most physicists think of the SM as an effective theory that has to be replaced by a more fundamental theory above the TeV scale. What the word effective really means will hopefully be clear at later stages of our book. For the time being we will list some problems and open questions of the SM"--

The Anti-B ---] D* L Anti-nu Form Factor at Zero Recoil from Three-flavor Lattice QCD

The Anti-B ---] D* L Anti-nu Form Factor at Zero Recoil from Three-flavor Lattice QCD PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 44

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The Babar Physics Book

The Babar Physics Book PDF Author: Paul F. Harrison
Publisher:
ISBN:
Category : CP violation (Nuclear physics)
Languages : en
Pages : 550

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The Decay Constants F(B+) and F(D+) from Three-flavor Lattice QCD.

The Decay Constants F(B+) and F(D+) from Three-flavor Lattice QCD. PDF Author: R. T. Evans
Publisher:
ISBN:
Category :
Languages : en
Pages : 6

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Book Description
We present new results for f{sub B+} and f{sub D+} from the MILC 2+1 flavor a = 0.09fm 'fine' lattice. We use clover heavy quarks in the Fermilab interpretation and improved staggered light quarks. Lattice results from partially quenched QCD fix the parameters of staggered chiral perturbation theory which is used in the extrapolation to the physical decay constants.

B- and D-meson Decay Constants from Three-flavor Lattice QCD.

B- and D-meson Decay Constants from Three-flavor Lattice QCD. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 63

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Book Description
We calculate the leptonic decay constants of B_{(s)} and D_{(s)} mesons in lattice QCD using staggered light quarks and Fermilab bottom and charm quarks. We compute the heavy-light meson correlation functions on the MILC asqtad-improved staggered gauge configurations which include the effects of three light dynamical sea quarks. We simulate with several values of the light valence- and sea-quark masses (down to m̃_s/10) and at three lattice spacings (a ̃0.15, 0.12, and 0.09 fm) and extrapolate to the physical up and down quark masses and the continuum using expressions derived in heavy-light meson staggered chiral perturbation theory. We renormalize the heavy-light axial current using a mostly nonperturbative method such that only a small correction to unity must be computed in lattice perturbation theory and higher-order terms are expected to be small. We obtain f_{B+̂} = 196.9(8.9) MeV, f_{B_s} = 242.0(9.5) MeV, f_{D+̂} = 218.9(11.3) MeV, f_{D_s} = 260.1(10.8) MeV, and the SU(3) flavor-breaking ratios f_{B_s}/f_{B} = 1.229(26) and f_{D_s}/f_{D} = 1.188(25), where the numbers in parentheses are the total statistical and systematic uncertainties added in quadrature.

Physics Briefs

Physics Briefs PDF Author:
Publisher:
ISBN:
Category : Physics
Languages : en
Pages : 1116

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