====== TTP07-37 Resolving the sign ambiguity in Delta Gamma_s with B_s -> D_s K ======
 
 
   <hidden TTP07-37  Resolving the sign ambiguity in Delta Gamma_s with B_s -> D_s K > The analysis of tagged $B_s\to J/\psi \phi$ decays determines
 the CP phase $\phi_s$ in \bbms\ with a two--fold ambiguity. The solutions
 differ in the sign of $\cos \phi_s$ which equals the sign of the width
 difference $\dg_s$ among the two $B_s$ mass eigenstates. We point out
 that this ambiguity can be removed with the help of $B_s \to D_s K$
 decays. We compare untagged and tagged strategies and find the tagged
 analysis more promising. The removal of the sign ambiguity in $\dg_s$
 can be done with relatively low statistics and could therefore
 be a target for the early stage of $B_s \to D_s K$ studies.
 </hidden>
|**Soumitra Nandi and Ulrich Nierste**  | 
|**  Phys. Rev. D   77 054010 2008  **  |
| {{preprints:2007:ttp07-37.pdf|PDF}} {{preprints:2007:ttp07-37.ps|PostScript}} [[http://arxiv.org/abs/0801.0143|arXiv]]   |
| |