Search for an X(3872) charged partner in the decay mode X- --> J/psi pi- pi0 in the B meson decays B0 --> X- K+ and B- --> X- Ks

The authors have performed a search for a charged partner of the X(3872) decaying to J/{psi}{pi}{sup {+-}}{pi}{sup 0}. The results set upper limits on the product branching fractions of B({bar B}{sup 0}/B{sup 0} --> X{sup {+-}}K{sup {-+}}, X{sup {+-}} --> J/{psi}{sup {+-}}{pi}{sup 0}) X{sup {+-}}K{sup 0}{sub s}, X{sup {+-}} --> J/{psi}{sup {+-}}{pi}{sup 0} < 11 x 10{sup -6} at the 90% confidence level. They exclude the isovector X hypothesis with a likelihood ratio test and with their experiments results they obtain a ratio greater than 600 for the null hypothesis relative to the isovector signal hypothesis.