CERN Accelerating science

LHCb Note
Report number	LHCb-CONF-2012-022 ; CERN-LHCb-CONF-2012-022
Title	Measurement of the flavour-specific CP violating asymmetry $a_{sl}^s$ in $\bar{B}_s^0$ decays
Corporate author(s)	The LHCb Collaboration
Collaboration	LHCb Collaboration
Submitted to	36th International Conference on High Energy Physics, Melbourne, Australia, 4 - 11 Jul 2012
Submitted by	anu.liisa.saarelainen@cern.ch on 11 Jul 2012
Subject category	Particle Physics - Experiment
Accelerator/Facility, Experiment	CERN LHC ; LHCb
Free keywords	Flavour physics ; B physics ; CP violation
Abstract	The CP violating asymmetry $a_{sl}^s$ is studied using samples of $\bar{B}_s^0$ and $B_s^0$ semileptonic decays in pp collisions at a centre-of-mass energy of 7 TeV using an integrated luminosity of 1/fb provided by the LHC. The detected final states are $D_s^\pm\mu^\mp$ and $D_s^-\mu^+$ with $D_s^\pm$ reconstructed in the $\phi\pi^\pm$ mode. The analysis is summed over $\bar{B}_s^0$ and $B_s^0$ initial states, so that flavour tagging is unnecessary, and integrated with respect to decay time. Data driven methods have been developed to measure all the efficiency ratios needed to determine $a_{sl}^s$ . We obtain $a_{sl}^s = (-0.24 \pm 0.54 \pm 0.33)$%, where the first uncertainty is statistical and the second systematic.
Copyright/License	Preprint: (License: CC-BY-4.0)

Corresponding record in: Inspire
Email contact(s) : stone@physics.syr.edu ; Marina.Artuso@cern.ch