Bto Kl^+l^- decay form factors from three-flavor lattice QCD
read the original abstract
We compute the form factors for the $B \to Kl^+l^-$ 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 $f_+(q^2)$, $f_0(q^2)$, and $f_T(q^2)$, where $q^2$ is the momentum transfer, together with a comprehensive examination of systematic errors. Lattice QCD determines the form factors for a limited range of $q^2$, 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. We use this complete description of the form factors to test QCD predictions of the form factors at high and low $q^2$. We also compare a Standard-Model calculation of the branching ratio for $B \to Kl^+l^-$ with experimental data.
This paper has not been read by Pith yet.
Forward citations
Cited by 6 Pith papers
-
Phenomenology of Non-Abelian Gauge and Goldstone Bosons in a U(2) Flavor Model
SU(2)_F bosons in a U(2)_F flavor model induce unsuppressed flavor-violating couplings, with K to pi X and mu to e X constraining the breaking scale v_phi to 10^11-10^12 GeV for light bosons and other processes constr...
-
Probing vector- vs scalar-mediator dark-matter scenarios in $B\to (K,K^*) M_X$ decays
Scalar and vector dark-matter mediator scenarios in B decays are distinguishable via differential distributions, with data imposing M_V ≲ 3 GeV for vectors but no mass bound for scalars.
-
Correlated $b \to s$ and $s \to d$ Rare Semileptonic Transitions in the Standard Model Effective Field Theory
SMEFT global fit to b→s anomalies with complex Wilson coefficients shows left-handed four-fermion operators preferred and demonstrates that U(3)^5 or U(2)^5 flavor symmetry restores consistency with kaon data.
-
Determination of $B$-meson distribution amplitudes from $B\to \pi,K,D$ transition form factors
Global fit of B to pi, K, D form factors from lattice QCD and LCSR yields lambda_B = 217(19) MeV with model variations and |V_ub| = 3.68(13) x 10^{-3}.
-
Analysis of $B\to KM_X$ and $B\to K^* M_X$ decays in scalar- and vector-mediator dark-matter scenarios
Belle-II excess in B to K/K* + missing energy is explained by dark matter fermion pair production via scalar or vector mediator, with discrimination possible through decay rate inspections.
-
FLAG Review 2024
The FLAG 2024 review provides updated averages of lattice QCD determinations for quark masses, decay constants, form factors, mixing parameters, and nucleon matrix elements.
discussion (0)
Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.