Search for the Z[subscript 1](4050)[superscript +] and Z[subscript 2](4250)[superscript +] states in B̅ [superscript 0]→[subscript χc1] K[superscript -]π[superscript +] and B[superscript +] →[subscript χc1]K[superscript 0 over subscript S}π[superscript +]

Abstract

We search for the Z[subscript 1](4050)[superscript +] and Z[subscript 2](4250)[superscript +] states, reported by the Belle Collaboration, decaying to [subscript χc1]π[superscript +] in the decays B̅ [superscript 0]→[subscript χc1] K[superscript -]π[superscript +] and B[superscript +] →[subscript χc1]K[superscript 0 over subscript S}π[superscript +] where [subscript χc1]→J/ψγ. The data were collected with the BABAR detector at the SLAC PEP-II asymmetric-energy e[superscript +]e[superscript -] collider operating at center-of-mass energy 10.58 GeV, and correspond to an integrated luminosity of 429 fb[superscript -1]. In this analysis, we model the background-subtracted, efficiency-corrected [subscript χc1]π[superscript +] mass distribution using the Kπ mass distribution and the corresponding normalized Kπ Legendre-polynomial moments, and then test the need for the inclusion of resonant structures in the description of the [subscript χc1]π[superscript +] mass distribution. No evidence is found for the Z[subscript 1](4050)[superscript +] and Z[subscript 2](4250)[superscript +] resonances, and 90% confidence level upper limits on the branching fractions are reported for the corresponding B-meson decay modes.