Study of Upsilon(1S) radiative decays to gamma pi(+)pi(-) and gamma K+ K-

We study the (1S) radiative decays to γπ+π- and γK+K- using data recorded with the BABAR detector operating at the SLAC PEP-II asymmetric-energy e+e- collider at center-of-mass energies at the (2S) and (3S) resonances. The (1S) resonance is reconstructed from the decay (nS)→π+π-(1S), n=2, 3. Branching fraction measurements and spin-parity analyses of (1S) radiative decays are reported for the I=0 S-wave and f2(1270) resonances in the π+π- mass spectrum, the f2′(1525) and f0(1500) in the K+K- mass spectrum, and the f0(1710) in both.

We study the Upsilon(1S) radiative decays to gamma pi(+)pi(-) and gamma K+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 Upsilon(2S) and Upsilon(3S) resonances. The Upsilon(1S) resonance is reconstructed from the decay Upsilon(nS) -> pi(+)pi(-) Upsilon(1S), n =2, 3. Branching fraction measurements and spin-parity analyses of Upsilon(1S) radiative decays are reported for the I = 0 S-wave and f(2) (1270) resonances in the pi(+)pi(-) mass spectrum, the f'(2) (1525) and f(0) (1500) in the K+K mass spectrum, and the f(0)(1710) in both.