ISSN - 00319007, EISSN - 10797114, Physical Review Letters, 2013, vol. 111, p. -
Evidence of a new narrow resonance decaying to χc1γ in B→χc1γK
We report measurements of B→χc1γK and χc2γK decays using 772×106 BB̄ events collected at the Υ(4S) resonance with the Belle detector at the KEKB asymmetric-energy e+e- collider. Evidence of a new resonance in the χc1γ final state is found with a statistical significance of 3.8σ. This state has a mass of 3823.1±1.8(stat)±0.7(syst) MeV/c2, a value that is consistent with theoretical expectations for the previously unseen 1D23 cc̄ meson. We find no other narrow resonance and set upper limits on the branching fractions of the X(3872)→χc1γ and χc2γ decays. © 2013 American Physical Society.