We have looked for decay of Bs meson in the final state phi phi with the phi decayng to two charged Kaons.  This analysis uses a dataset of approximately 180 pb^-1 of data taken with the displaced track trigger of CDFII up to August 2003. Additionally we study the decays Bs-> J/psi phi in the same dataset to be used as a normalization signal for the extraction of the Branching Ratio of Bs->phi phi.
We have found a significant excess of events in the signal region and measure the Branching Ratio:

where the last error is due to the uncertainty in the Bs-> J/psi phi Branching Ratio.

This result has been produced for the winter conferences 2004 and have been blessed in the B Physcis Meeting on Thursday Apr 8^th, 2004.

A  complete description of the analysis is available here: html, ps.

If you have access to internal CDF documents more details can be found in  cdfnote 6937

• X.Li,G.Lu,Y.Yang "Charmless Bs->VV decays in QCD factorization", Phys Rev D68 (2003)114105 also available as hep-ph/0309136
• Y.Chen,H.Chen,B.Tseng "Charmless Hadronic Two-body Decays of the Bs Mesons". Phys.Rev. D59 (1999) 074003 also available as hep-ph/9809364

Phi->K+K- peak and sideband definition click on the picture for the eps version.
Sideband and signal region definition in the MBs-Mphi plane click on the picture for the eps version.
Bs->J/psi phi signal in the main trigger click on the picture for the eps version.
Bs->J/psi phi signal in the prescaled (LOWPT) trigger click on the picture for the eps version.
Bs->phi phi signal in the main trigger 8 candidates found with 0.75 expected background events click on the picture for the eps version.
Bs->phi phi signal in the prescaled (LOWPT) trigger 4 candidates found with 1.2 expected background events click on the picture for the eps version.
Bs->phi phi signal in the combined dataset 12 candidates found with 1.95 expected background events click on the picture for the eps version.