Searches for Isospin-Violating Transitions χ_{c0,2} → π⁰η_c.

We present the first upper-limit measurement of the branching fractions of the isospin-violating transitions χ{c0,2} → π⁰η{c}. The measurements are performed using 106 x 10⁶ ψ(3686) events accumulated with the BESIII detector at the BEPCII e⁺e⁻ collider at a center-of-mass energy corresponding to the ψ(3686) mass. We obtained upper limits on the branching fractions at a 90% confidence level of B(χ{c0,2} → π⁰η{c}) < 3.2 x 10⁻³.