B to rho ell nu form factors in lattice QCD

Bowler, K.C.; Gill, J.; Maynard, C.M.; Flynn, Jonathan M.

doi:10.1088/1126-6708/2004/05/035

Cited by 38 publications

(70 citation statements)

References 38 publications

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“…The calculation presented here makes it clear that matrix elements featuring resonating hadronic systems can be rigorously studied using lattice QCD. Obvious extensions include nucleon resonances like the ∆ in γ N → ∆ → N π [77][78][79], and heavy flavor decays which feature resonances, like B → ππ ν [80]. Moving to higher mass resonances, the extension into the coupledchannel case, accommodated by the formalism laid down in Refs.…”

Section: Discussionmentioning

confidence: 99%

ππ→πγamplitude and the resonantρ→πγtransition from lattice QCD

et al. 2016

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We present a determination of the P -wave ππ → πγ transition amplitude from lattice quantum chromodynamics. Matrix elements of the vector current in a finite-volume are extracted from three-point correlation functions, and from these we determine the infinite-volume amplitude using a generalization of the Lellouch-Lüscher formalism. We determine the amplitude for a range of discrete values of the ππ energy and virtuality of the photon, and observe the expected dynamical enhancement due to the ρ resonance. Describing the energy dependence of the amplitude, we are able to analytically continue into the complex energy plane and from the residue at the ρ pole extract the ρ → πγ transition form factor. This calculation, at mπ ≈ 400 MeV, is the first to determine the form factor of an unstable hadron within a first principles approach to QCD.

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Section: Discussionmentioning

confidence: 99%

ππ→πγamplitude and the resonantρ→πγtransition from lattice QCD

et al. 2016

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“…In this respect it is worth making a fit just to Belle's We show the predictions from LCSR [12] (squares), and lattice QCD from the SPQcdR [13] (up-triangles) and UKQCD [14] (circles) collaborations. Right-bottom panel:…”

Section: Resultsmentioning

confidence: 99%

“…The Omnès functional form depends on the form factor values at the subtraction points and those values are treated as free parameters. These, together with |V ub |, are fitted both to B → ρ l + ν l recent partial branching fraction measurements from Belle [8], BaBar [2] and CLEO [11] collaborations, as well as to theoretical results for the B → ρ form factors obtained using LCSR [12] and lattice calculations by the SPQcdR [13] and UKQCD [14] collaborations. For the ρ → ππ decay we use a phenomenological vertex where the coupling constant has been fixed to the on-shell ρ meson decay width.…”

Section: +015mentioning

confidence: 99%

“…[3], we use three subtraction points at q 2 = 0, 2q ), for F = V, A 1 , A 2 , are treated as free parameters as will be |V ub |. The values of these ten parameters are then fitted to reproduce form factor theoretical results obtained in LCSR [12] and lattice calculations [13,14], and experimental measurements of partial branching fractions obtained by the CLEO [11], BaBar [2] and Belle [8] collaborations. The partial branching fractions are defined as…”

Section: Fitting Proceduresmentioning

confidence: 99%

“…[12]. For higher q 2 we will use the lattice results by the SPQcdR [13] and UKQCD [14] collaborations. All of them are collected in Table II.…”

Section: A Experimental and Theoretical Inputmentioning

confidence: 99%

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B→ρsemileptonic decays and|Vub|

2014

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We reevaluate the B → ρ l + ν l decay width as a full B → ππ l + ν l four-particle decay, in which the two final pions are produced via an intermediate ρ meson. The decay width can be written as a convolution of the B → ρ l + ν l decay width, for an off-shell ρ, with the ρ → ππ line shape. This allows to fully incorporate the effects of the finite ρ meson width. As shown, consideration of the ρ meson width effects increase the |V ub | value by some 8%, rendering it in better agreement with the determination based in the B → π decay. We take the q 2 dependence of the B → ρ semileptonic form factors from a dispersive Omnès representation. The Omnès subtraction constants and the overall normalization parameter |V ub | are fitted to light cone sum rules and lattice QCD theoretical form-factor calculations, in the low and high q 2 regions respectively, together to the CLEO, BaBar and Belle experimental partial branching fraction distributions. The extracted value from this global fit is |V ub | = (3.12 ± 0.13) × 10 −3 , in agreement with the average B → π exclusive value |V ub | = (3.23 ± 0.31) × 10 −3 quoted by the Particle Data Group. The extracted value increases to |V ub | = (3.51 ± 0.16) × 10 −3 if only the most recent Belle Collaboration data is used. This latter value is in agreement with different theoretical determinations based in the B → π semileptonic decay and the values obtained by the CKMfitter and UTfit groups. In any case a clear tension with the |V ub | value extracted from inclusive semileptonic b → u decays still persists.

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Theoretical and phenomenological constraints on form factors for radiative and semi-leptonic B-meson decays

Bharucha

Feldmann

Wick

2010

J. High Energ. Phys.

102

128

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We study transition form factors for radiative and rare semi-leptonic B-meson decays into light pseudoscalar or vector mesons, combining theoretical constraints and phenomenological information from Lattice QCD, light-cone sum rules, and dispersive bounds. We pay particular attention to form factor parameterisations which are based on the so-called series expansion, and study the related systematic uncertainties on a quantitative level. In this context, we also provide the NLO corrections to the correlation function between two flavour-changing tensor currents, which enters the unitarity constraints for the coefficients in the series expansion. * a.k.m.bharucha@durham.ac.uk

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B to rho ell nu form factors in lattice QCD

Cited by 38 publications

References 38 publications

ππ→πγamplitude and the resonantρ→πγtransition from lattice QCD

ππ→πγamplitude and the resonantρ→πγtransition from lattice QCD

B→ρsemileptonic decays and|Vub|

Theoretical and phenomenological constraints on form factors for radiative and semi-leptonic B-meson decays

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B to rho ell nu form factors in lattice QCD

Cited by 38 publications

References 38 publications

ππ→πγ*amplitude and the resonantρ→πγ*transition from lattice QCD

ππ→πγ*amplitude and the resonantρ→πγ*transition from lattice QCD

B→ρsemileptonic decays and|Vub|

Theoretical and phenomenological constraints on form factors for radiative and semi-leptonic B-meson decays

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ππ→πγamplitude and the resonantρ→πγtransition from lattice QCD

ππ→πγamplitude and the resonantρ→πγtransition from lattice QCD