QCD sum rules for parameters of the 
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-meson distribution amplitudes

Rahimi, Muslem; Wald, Marcel

doi:10.1103/physrevd.104.016027

“…Introducing the higher dimensional correlation functions, however, turns out to worsen the OPE convergence in contrast to the previously adopted non-diagonal ones, as already observed in [73]. In view of an absence of the satisfactory evaluation for these two non-perturbative parameters, we will follow closely the strategy of [9,15] such that the numerical intervals of the combinations 1 accommodate the obtained results from the twopoint sum rules [11,72] and particularly lie within the upper bounds for λ 2 E and λ 2 H derived from the diagonal correlation functions [73]. In addition, the HQET parameter Λ entering the soft-collinear factorization formulae (3.35) and (3.46) can be identified as the "effective mass" of the heavy-meson state [50,60]:…”

Section: Jhep02(2022)141mentioning

confidence: 77%

“…The dominating discrepancies for the numerical values displayed in [11] and [72] JHEP02(2022)141 can be attributed to the sizeable QCD radiative correction to the dimension-five quark-gluon condensate and the yet higher-power contribution from the dimension-six vacuum condensate at tree level, which have been included in the updated computation [72] with a further improvement on the (partial)-NLL resummation of the emerged large logarithms appearing in the HQET sum rules. Instead of constructing the desired sum rules from the appropriate correlation functions with one two-body and one three-body local current, the authors of [73] suggested to employ the diagonal Green functions for the sake of obtaining the alternative sum rules for λ 2 E and λ 2 H , with the expectation that the parton-hadron duality approximation becomes more reliable due to the positive definite property obviously. Introducing the higher dimensional correlation functions, however, turns out to worsen the OPE convergence in contrast to the previously adopted non-diagonal ones, as already observed in [73].…”

Section: Jhep02(2022)141mentioning

confidence: 99%

“…Instead of constructing the desired sum rules from the appropriate correlation functions with one two-body and one three-body local current, the authors of [73] suggested to employ the diagonal Green functions for the sake of obtaining the alternative sum rules for λ 2 E and λ 2 H , with the expectation that the parton-hadron duality approximation becomes more reliable due to the positive definite property obviously. Introducing the higher dimensional correlation functions, however, turns out to worsen the OPE convergence in contrast to the previously adopted non-diagonal ones, as already observed in [73]. In view of an absence of the satisfactory evaluation for these two non-perturbative parameters, we will follow closely the strategy of [9,15] such that the numerical intervals of the combinations 1 accommodate the obtained results from the twopoint sum rules [11,72] and particularly lie within the upper bounds for λ 2 E and λ 2 H derived from the diagonal correlation functions [73].…”

Section: Jhep02(2022)141mentioning

confidence: 99%

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QCD factorization for the four-body leptonic B-meson decays

Wang

¹

,

Wang

²

,

Wei

³

2022

J. High Energ. Phys.

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Employing the QCD factorization formalism we compute $$ {B}_u^{-}\to {\gamma}^{\ast}\mathrm{\ell}{\overline{v}}_{\mathrm{\ell}} $$ B u − → γ ∗ ℓ v ¯ ℓ form factors with an off-shell photon state possessing the virtuality of order mb ΛQCD and $$ {m}_b^2 $$ m b 2 , respectively, at next-to-leading order in QCD. Perturbative resummation for the enhanced logarithms of mb/ΛQCD in the resulting factorization formulae is subsequently accomplished at next-to-leading logarithmic accuracy with the renormalization-group technique in momentum space. In particular, we derive the soft-collinear factorization formulae for a variety of the subleading power corrections to the exclusive radiative $$ {B}_u^{-}\to {\gamma}^{\ast }{W}^{\ast } $$ B u − → γ ∗ W ∗ form factors with a hard-collinear photon at $$ \mathcal{O}\left({\alpha}_s^0\right) $$ O α s 0 . We further construct a complete set of the angular observables governing the full differential distribution of the four-body leptonic decays $$ {B}_u^{-}\to {\mathrm{\ell}}^{\prime }{\overline{\mathrm{\ell}}}^{\prime}\mathrm{\ell}{\overline{v}}_{\mathrm{\ell}} $$ B u − → ℓ ′ ℓ ¯ ′ ℓ v ¯ ℓ with ℓ, ℓ′ ∈ {e, μ} and then perform an exploratory phenomenological analysis for a number of decay observables accessible at the LHCb and Belle II experiments, with an emphasis on the systematic uncertainties arising from the shape parameters of the leading-twist B-meson light-cone distribution amplitude in heavy quark effective theory.

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“…Moreover, the continuum threshold of K * 0 meson, s 0 is equal to (4.4 ± 0.4)GeV 2 [33]. The values of the parameters λ 2 E and λ 2 H of the B s -meson DA's are chosen as: λ 2 E = (0.01 ± 0.01) GeV 2 and λ 2 H = (0.15 ± 0.05) GeV 2 [35]. The two-particle DA's of B s -meson, ϕ + (ω) and ϕ − (ω) have the most important contribution in estimation of the form factors f + , f − , and f T .…”

Section: Numerical Analysismentioning

confidence: 99%

Semileptonic $B_{s}\to K_0^*(1430)$ transitions with the light-cone sum rules

Khosravi

2022

Preprint

0

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In the SU(3)F symmetry limit, using two-and three-particle distribution amplitudes of B ± -meson for Bs, the transition form factors of semileptonic Bs → K * 0 (1430) decays are calculated in the framework of the light-cone sum rules. The two-particle distribution amplitudes, ϕ + (ω) and ϕ − (ω) have the most important contribution in estimation of the form factors f+(q 2 ), f−(q 2 ) and fT (q 2 ). The knowledge of the behavior of ϕ + (ω) is still rather limited. Therefore, we consider three different parametrizations for the shapes of ϕ + (ω) that are derived from the phenomenological models. Using the form factors f+, f− and fT , the semileptonic Bs → K * 0 (1430)l νl and Bs → K * 0 (1430)l l/ν ν, l = e, µ, τ decays are analyzed. The branching fractions for the aforementioned decays, in addition the longitudinal lepton polarization asymmetries are calculated. A comparison between our results with predictions of other approaches is provided.

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Precision calculations of Bd,s → π, K decay form factors in soft-collinear effective theory

Cui

¹

,

Huang

²

,

Shen

³

et al. 2023

J. High Energ. Phys.

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We improve QCD calculations of the semileptonic Bd,s→ π, K decay form factors at large hadronic recoil by implementing the next-to-leading-logarithmic resummation for the obtained leading-power light-cone sum rules in the soft-collinear effective theory (SCET) framework and by computing for the first time the non-vanishing spectator-quark mass correction dictating the SU(3)-flavour symmetry breaking effects between these fundamental quantities at the one-loop accuracy. Additionally, we endeavour to investigate a variety of the subleading-power contributions to these heavy-to-light form factors at $$ \mathcal{O}\left({\alpha}_s^0\right) $$ O α s 0 with the same methodology, by including the higher-order terms in the heavy-quark expansion of the hard-collinear quark propagator, by evaluating the desired effective matrix element of the next-to-leading-order term "Image missing" in the SCETI representation of the weak transition current, by taking into account the off-light-cone contributions of the two-body heavy-quark effective theory (HQET) matrix elements as well as the three-particle higher-twist corrections from the subleading bottom-meson light-cone distribution amplitudes (LCDAs), and by computing the twist-five and twist-six four-body higher-twist effects with the aid of the factorization approximation. Having at our disposal the SCET sum rules for the exclusive B-meson decay form factors under discussion, we further explore in detail numerical implications of the newly computed subleading-power corrections by employing the three-parameter model for both the leading-twist and higher-twist B-meson distribution amplitudes. Taking advantage of the customary Bourrely-Caprini-Lellouch (BCL) parametrization for the complete set of the semileptonic Bd,s→ π, K form factors, we then determine the correlated numerical results for the interesting series coefficients, by carrying out the simultaneous fit of the exclusive B-meson decay form factors to both the achieved SCET sum rule predictions at small momentum transfer (q2) and the available lattice QCD results at large momentum transfer. Subsequently, we perform a comprehensive phenomenological analysis of the full angular observables, the lepton-flavour university ratios and the lepton polarization asymmetries for the flavour-changing charged- current $$ B\to \pi \ell {\overline{\nu}}_{\ell } $$ B → π ℓ ν ¯ ℓ and $$ {B}_s\to K\ell {\overline{\nu}}_{\ell } $$ B s → K ℓ ν ¯ ℓ decays (with ℓ = μ, τ) together with the differential q2-distribution for the exclusive rare $$ B\to K{\nu}_{\ell }{\overline{\nu}}_{\ell } $$ B → K ν ℓ ν ¯ ℓ decays in the Standard Model.

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QCD sum rules for parameters of the B -meson distribution amplitudes

Cited by 16 publications

References 48 publications

QCD factorization for the four-body leptonic B-meson decays

QCD factorization for the four-body leptonic B-meson decays

Semileptonic $B_{s}\to K_0^*(1430)$ transitions with the light-cone sum rules

Precision calculations of Bd,s → π, K decay form factors in soft-collinear effective theory

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