Dispersive bounds for local form factors in ${\Lambda }_b\to \Lambda$ transitions

Abstract

We investigate the ten independent local form-factors relevant to the $b$-baryon decay ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$, combining information of lattice QCD and dispersive bounds. We propose a novel parametrization of the form factors in terms of orthonormal polynomials that diagonalizes the form factor contributions to the dispersive bounds. This is a generalization of the unitarity bounds developed for meson-to-meson form-factors. In contrast to ad-hoc parametrizations of these form factors, our parametrization provides a degree of control of the form-factor uncertainties at large hadronic recoil. This is of phenomenological interest for theoretical predictions of, e.g., ${\Lambda }_b\to \Lambda \gamma$ and ${\Lambda }_b\to \Lambda {\ell }^{+}{\ell }^{-}$ decay processes.

20 pages, 4 figures

References in corpus (8)

• $R(D^{\ast })$, $|V_{cb}|$, and the Heavy Quark Symmetry relations between form factors
• Model independent extraction of the proton charge radius from electron scattering
• EOS -- A Software for Flavor Physics Phenomenology
• Bayesian analysis of $b\to s{\mu }^{+}{\mu }^{-}$ Wilson coefficients using the full angular distribution of ${\Lambda }_b\to \Lambda (\to p{\pi }^{-}){\mu }^{+}{\mu }^{-}$ decays
• Effects of scalar leptoquark on semileptonic ${\Lambda }_b$ decays
• Precision Model-Independent Bounds from Global Analysis of $b\to c\ell \nu$ Form Factors
• $|V_{cb}|$, Lepton Flavour Universality and $SU(3{)}_F$ symmetry breaking in $B_s\to D_s^{(\ast )}\ell {\nu }_{\ell }$ decays through unitarity and lattice QCD
• Lepton flavour violation in rare ${\Lambda }_b$ decays

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• Constraining $|V_{cs}|$ and physics beyond the Standard Model from exclusive (semi)leptonic charm decays
• A model-independent parameterization of $B\to \pi \pi \ell \nu$ decays
• Invisible and Semi-invisible Decays of Bottom Baryons
• Semileptonic neutral current decays of ${\Xi }_b$ with dileptons or dineutrinos in the final state
• ${\Xi }_b\to \Xi$ form factors from lattice QCD and Standard-Model predictions for ${\Xi }_b\to \Xi {\mu }^{+}{\mu }^{-}$ and ${\Xi }_b\to \Xi \gamma$ decays