Study of Υ(1s) Radiative Decays to γπ⁺π⁻ and γK⁺K⁻

We study the Υ(1S) radiative decays to γπ⁺π⁻ and γK⁺K⁻ using data recorded with the BABAR detector operating at the SLAC PEP-11 asymmetric-energy e⁺e⁻ collider at center-of-mass energies at the Υ(2S) and Υ(3S) resonances. The Υ(1S) resonance is reconstructed from the decay Υ(nS) → π⁺π⁻ Υ(1S), n =2, 3. Branching fraction measurements and spin-parity analyses of Υ(1S) radiative decays are reported for the I = 0 S-wave and ∫₂ (1270) resonances in the π⁺π⁻ mass spectrum, the ∫′₂ (1525) and ∫₀ (1500) in the K⁺K⁻ mass spectrum, and the ∫₃(1710) in both.