Measurements of the Bs0β effective lifetime in decays to CP-odd and
CP-even flavour specific final states allow to probe the width difference
ΞΞsβ and the CP-violating phase Οsβ of Bs0ββBΛs0β
mixing box-diagram. Measurements of the effective lifetime in the decay
channels Bs0ββK+Kβ and BΛs0ββJ/Οf0β(980) are presented, as well as a measurement of ΞΞsβ and
Ξsβ performed by a tagged time-dependent angular analysis of Bs0ββJ/ΟΟ decays and a measurement of the sign of ΞΞsβ, using data collected during 2011 with the LHCb detector.Comment: Proceedings of CKM 2012, the 7th International Workshop on the CKM
Unitarity Triangle, University of Cincinnati, USA, 28 September - 2 October
201