Λ[subscript b]→Λℓ[superscript +]ℓ[superscript -] form factors and differential branching fraction from lattice QCD
We present the first lattice QCD determination of the Λ[subscript b→]Λ transition form factors that govern the rare baryonic decays Λ[subscript b→]Λℓ[superscript +]ℓ[superscript -] at leading order in heavy-quark effective theory. Our calculations are performed with 2+1 flavors of domain-wall fermio...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
| Published: |
American Physical Society
2013
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| Online Access: | http://hdl.handle.net/1721.1/79595 https://orcid.org/0000-0002-0400-8363 |
| Summary: | We present the first lattice QCD determination of the Λ[subscript b→]Λ transition form factors that govern the rare baryonic decays Λ[subscript b→]Λℓ[superscript +]ℓ[superscript -] at leading order in heavy-quark effective theory. Our calculations are performed with 2+1 flavors of domain-wall fermions, at two lattice spacings and with pion masses down to 227 MeV. Three-point functions with a wide range of source-sink separations are used to extract the ground-state contributions. The form factors are extrapolated to the physical values of the light-quark masses and to the continuum limit. We use our results to calculate the differential branching fractions for Λ[subscript b→]Λℓ[superscript +]ℓ[superscript -] with ℓ=e, μ, τ within the standard model. We find agreement with a recent CDF measurement of the Λ[subscript b→]Λμ[superscript +]μ[superscript -] differential branching fraction. |
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