Extraction of bare form factors for Bs →Kℓν decays in nonperturbative HQET

Bahr, Felix; Banerjee, Debasish; Bernardoni, Fabio; Koren, Mateusz; Simma, Hubert; Sommer, Rainer

doi:10.1142/s0217751x19501665

Cited by 13 publications

(11 citation statements)

References 50 publications

(96 reference statements)

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“…We instead show in Fig. 4 principal correlators for 4 ≤ (2π/L) −1 ap z ≤ 8, where now the eigenvectors are phased with two units of allowed lattice momenta (6). Though the principle correlators for the higher excited states could not be resolved in such highly boosted frames, the resolution of the ground-state nucleon to at least ap z = 6 (2π/L) marks a considerable improvement in the distillation/GEVP infrastructure for the study of hadron structure.…”

Section: Efficacy Of Phased Distillation and Nucleon Dispersionsmentioning

confidence: 99%

“…The ground-state nucleon principal correlators for the a094m358 ensemble using a projected interpolator within each momentum channel obtained from the B p = 0 interpolator basis subduced into the relevant little group. The eigenvectors are phased with two units of momentum (6). Principal correlator fits (11) are shown with colored bands, while excluded data are in grey.…”

Section: Efficacy Of Phased Distillation and Nucleon Dispersionsmentioning

confidence: 99%

“…Nucleon effective energies for the a094m278 ensemble using a projected interpolator obtained from the B p= 0 and B p = 0 bases subduced into the relevant little group, together with continuum expectations (dashed), and 2-state fits (bands), where in each case the darker region denotes the time series included in the fit. No phasing was used to extract the ground-state nucleon energy for lattice momenta apz ∈ Z5, while apz = 4 (2π/L) was also determined with two units of phasing (6). In the case of apz = 4 (2π/L), the results with and without phased eigenvectors are shown as the green and red points respectively, clearly demonstrating the need for phasing.…”

Section: B Chargesmentioning

confidence: 99%

“…This robust momentum-smearing technique is now ubiquitous in lattice studies that demand a wide range of momenta, such as the mapping of nucleon electromagnetic form factors (FFs) [4], generalized FFs [5], and semi-leptonic decay FFs needed to quantify elements of the Cabibbo-Kobayashi-Maskawa matrix [6,7]. Perhaps the greatest usage has been seen in LQCD calculations of matrix elements of certain non-local space-likeseparated operators, which when computed over a range of momenta can be related to various light-cone distributions fundamental to hadron structure.…”

Section: Introductionmentioning

confidence: 99%

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Distillation at High-Momentum

Egerer,

Edwards,

Orginos

et al. 2020

Preprint

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Extraction of hadronic observables at finite-momenta from Lattice QCD (LQCD) is constrained by the well-known signal-to-noise problems afflicting all such LQCD calculations. Traditional quark smearing algorithms are commonly used tools to improve the statistical quality of hadronic n-point functions, provided operator momenta are small. The momentum smearing algorithm of Bali et al. extends the range of momenta that are cleanly accessible, and has facilitated countless novel lattice calculations. Momentum smearing has, however, not been explicitly demonstrated within the framework of distillation. In this work we extend the momentum-smearing idea, by exploring a few modifications to the distillation framework. Together with enhanced time slice sampling and expanded operator bases engendered by distillation, we find ground-state nucleon energies can be extracted reliably for | p| 3 GeV and matrix elements featuring a large momentum dependence can be resolved.

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Section: Efficacy Of Phased Distillation and Nucleon Dispersionsmentioning

confidence: 99%

Section: Efficacy Of Phased Distillation and Nucleon Dispersionsmentioning

confidence: 99%

Section: B Chargesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Distillation at High-Momentum

Egerer,

Edwards,

Orginos

et al. 2020

Preprint

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“…Whereas Monte Carlo data from different gauge field ensembles is uncorrelated by construction, the full covariance matrix does not assume a block diagonal form, but receives additional contributions induced by common renormalisation and improvement parameters as well as the mass shifting procedure 7. Note that χ 2 exp was already successfully applied before in a fit analysis of HQET correlators in the context of extracting semi-leptonic form factors[72].…”

mentioning

confidence: 99%

Determination of the charm quark mass in lattice QCD with 2 + 1 flavours on fine lattices

Heitger

Joswig

Kuberski

2021

J. High Energ. Phys.

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We present a determination of the charm quark mass in lattice QCD with three active quark flavours. The calculation is based on PCAC masses extracted from Nf = 2 + 1 flavour gauge field ensembles at five different lattice spacings in a range from 0.087 fm down to 0.039 fm. The lattice action consists of the O(a) improved Wilson-clover action and a tree-level improved Symanzik gauge action. Quark masses are non-perturbatively O(a) improved employing the Symanzik-counterterms available for this discretisation of QCD. To relate the bare mass at a specified low-energy scale with the renormalisation group invariant mass in the continuum limit, we use the non-pertubatively known factors that account for the running of the quark masses as well as for their renormalisation at hadronic scales. We obtain the renormalisation group invariant charm quark mass at the physical point of the three-flavour theory to be Mc = 1486(21) MeV. Combining this result with five-loop perturbation theory and the corresponding decoupling relations in the $$ \overline{\mathrm{MS}} $$ MS ¯ scheme, one arrives at a result for the renormalisation group invariant charm quark mass in the four-flavour theory of Mc(Nf = 4) = 1548(23) MeV, where effects associated with the absence of a charmed, sea quark in the non-perturbative evaluation of the QCD path integral are not accounted for. In the $$ \overline{\mathrm{MS}} $$ MS ¯ scheme, and at finite energy scales conventional in phenomenology, we quote $$ {m}_{\mathrm{c}}^{\overline{\mathrm{MS}}} $$ m c MS ¯ ($$ {m}_{\mathrm{c}}^{\overline{\mathrm{MS}}} $$ m c MS ¯ ; Nf = 4) = 1296(19) MeV and $$ {m}_{\mathrm{c}}^{\overline{\mathrm{MS}}} $$ m c MS ¯ (3 GeV; Nf = 4) = 1007(16) MeV for the renormalised charm quark mass.

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

Cui

Huang

Shen

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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Extraction of bare form factors for Bs →Kℓν decays in nonperturbative HQET

Cited by 13 publications

References 50 publications

Distillation at High-Momentum

Distillation at High-Momentum

Determination of the charm quark mass in lattice QCD with 2 + 1 flavours on fine lattices

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

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