Dec 7, 2006
   The discovery of Sigma_b


ABSTRACT: 

   In recent months, the Tevatron reached a significant milestone
and delivered over 1fb-1 to both the D0 and CDF experiments. The
large sample of data and a powerful displaced vertex trigger
combine to give CDF the world's largest sample of fully
reconstructed Lambda_b's.  Using this sample, we observe four new
Lambda_b pi+/- resononances, consistent with the hypothesis of
the lowest-lying Sigma_b(*) baryon states. 




SPEAKER:      Petar		   Maksimovic