Results and prospects for Υ ( 5 S ) running at B - factories

During the last several years an opportunity for B s meson studies at the e e colliders running at the Υ(5S) resonance has been extensively explored. The first evidence for B s production at the Υ(5S) was found by the CLEO collaboration [1, 2] using a dataset of 0.42 fb collected in 2003. This study indicated that practicalB s measurements at the Υ(5S) are possible with a dataset of at least 20 fb, which can be easily collected at B factories running with ∼10cmsec luminosity. To test the feasibility of a B s physics program the Belle collaboration collected at the Υ(5S) a dataset of 1.86 fb in 2005. After the successful analysis of these data [3, 4], Belle collected a bigger sample of 21.7 fb in 2006.