New Strategy for B_s Branching Ratio Measurements and the Search for New Physics in B^0_s -> mu^+ mu^-

Understand

The LHCb experiment at CERN's Large Hadron Collider will soon allow us to enter a new era in the exploration of B_s decays.

• A particularly promising channel for the search of "new physics" is B^0_s -> mu^+ mu^-.
• The systematic key uncertainty affecting the measurement of this -- and in fact all B_s-decay branching ratios -- is the ratio of fragmentation functions f_d/f_s.
• As the presently available methods for determining f_d/f_s are not sufficient to meet the high precision at LHCb, we propose a new strategy using \bar B^0_s -> D_s^+ pi^- and \bar B^0_d -> D^+ K^-.