Observation of Bs0→ψ(2S)φ and measurement of the ratio of branching fractions B(Bs0→ψ(2S)φ)/B(Bs0→J/ψφ)

We report the first observation of B-s(0)->psi(2S)phi decay in pp collisions at root s=1.96 TeV using 360 pb(-1) of data collected by the CDF II detector at the Fermilab Tevatron. We observe 20.2 +/- 5.0 and 12.3 +/- 4.1 B-s(0)->psi(2S)phi candidates, in psi(2S)->mu(+)mu(-) and psi(2S)-> J/psi pi(+)pi(-) decay modes, respectively. We present a measurement of the relative branching fraction B(B-s(0)->psi(2S)phi)/B(B-s(0)-> J/psi phi)=0.52 +/- 0.13(stat)+/- 0.04(syst)+/- 0.06(BR) using the psi(2S)->mu(+)mu(-) decay mode.