Towards a model independent analysis of rare B decays

We propose to undertake a model-independent analysis of the inclusive decay rates and distributions in the processes \bgamaxs~ and \Bsell ~(B=B^\pm or B^0_d). We show how measurements of the decay rates and distributions in these processes would allow us to extract the magnitude and sign of the dominant Wilson coefficients of the magnetic moment operator \mb \bar{s}_L \sigma_{\mu \nu} b_R F^{\mu \nu } and the four-fermion operators (\bar{s}_L \gamma_\mu b_L)(\bar{\ell} \gamma^{\mu} \ell) and (\bar{s}_L \gamma_\mu b_L)(\bar{\ell} \gamma^{\mu}\gamma^5 \ell).