In:
Journal of High Energy Physics, Springer Science and Business Media LLC, Vol. 2023, No. 1 ( 2023-01-09)
Kurzfassung:
We derive new sum rules for the form factors of the $$ {B}_c\to J/\psi \ell {\overline{\nu}}_{\ell } $$ B c → J / ψ ℓ ν ¯ ℓ semileptonic transitions, employing the vacuum-to- B c correlation function of the J/ψ -interpolating and b → c weak currents. In the heavy quark limit and at a space-like momentum transfer to the weak current, a local operator-product expansion is valid for this correlation function. As a result, in the leading power, the non-perturbative input is reduced to the decay constant of B c meson. Furthermore, applying hadronic dispersion relation in the J/ψ channel, we find that a non-vanishing OPE spectral density in the duality interval of J/ψ emerges only at $$ \mathcal{O} $$ O ( α s ). We calculate this density in the relevant kinematic regime. The B c → J/ψ form factors at space-like momentum transfer are then calculated from the new sum rules.
Materialart:
Online-Ressource
ISSN:
1029-8479
DOI:
10.1007/JHEP01(2023)032
Sprache:
Englisch
Verlag:
Springer Science and Business Media LLC
Publikationsdatum:
2023
ZDB Id:
2027350-2
