How to employ B ¯ d 0 → J / ψ π η , K ¯ K $$ {\overline{B}}_d^0\to J/\psi \left(\uppi \eta, \overline{K}K\right) $$ decays to extract information on πη scattering

Abstract

Abstract We demonstrate that dispersion theory allows one to deduce crucial information on πη scattering from the final-state interactions of the light mesons visible in the spectral distributions of the decays B ¯ d 0 → J / ψ π 0 η , K + K − , K 0 K ¯ 0 $$ {\overline{B}}_d^0\to J/\psi \left({\pi}^0\eta, {K}^{+}{K}^{-},{K}^0{\overline{K}}^0\right) $$ . Thus high-quality measurements of these differential observables are highly desired. The corresponding rates are predicted to be of the same order of magnitude as those for B ¯ d 0 → J / ψ π + π − $$ {\overline{B}}_d^0\to J/\psi {\pi}^{+}{\pi}^{-} $$ measured recently at LHCb, letting the corresponding measurement appear feasible.

Keywords

• Chiral Lagrangians
• Heavy Quark Physics