Study of {Upsilon}(3S,2S){yields}{eta}{Upsilon}(1S) and {Upsilon}(3S,2S){yields}{pi}{sup +}{pi}{sup -}{Upsilon}(1S) hadronic transitions

We study the {Upsilon}(3S,2S){yields}{eta}{Upsilon}(1S) and {Upsilon}(3S,2S){yields}{pi}{sup +}{pi}{sup -}{Upsilon}(1S) transitions with 122x10{sup 6}{Upsilon}(3S) and 100x10{sup 6}{Upsilon}(2S) mesons collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider. We measure B[{Upsilon}(2S){yields}{eta}{Upsilon}(1S)]=(2.39{+-}0.31(stat.){+-}0.14(syst.))x10{sup -4} and {Gamma}[{Upsilon}(2S){yields}{eta}{Upsilon}(1S)]/{Gamma}[{Upsilon}(2S){yields}{pi}{sup +}{pi}{sup -}{Upsilon}(1S)]=(1.35{+-}0.17(stat.){+-}0.08(syst.))x10{sup -3}. We find no evidence for {Upsilon}(3S){yields}{eta}{Upsilon}(1S) and obtain B[{Upsilon}(3S){yields}{eta}{Upsilon}(1S)]<1.0x10{sup -4} and {Gamma}[{Upsilon}(3S){yields}{eta}{Upsilon}(1S)]/ {Gamma}[{Upsilon}(3S){yields}{pi}{sup +}{pi}{sup -}{Upsilon}(1S)]<2.3x10{sup -3} as upper limits at the 90% confidence level. We also provide improved measurements of the {Upsilon}(2S)-{Upsilon}(1S) and {Upsilon}(3S)-{Upsilon}(1S) mass differences, 562.170{+-}0.007(stat.){+-}0.088(syst.) MeV/c{sup 2} and 893.813{+-}0.015(stat.){+-}0.107(syst.) MeV/c{sup 2}, respectively.