Hi,
this is the spread sheet to compute the error on the ratio bch/b0.
http://www.slac.stanford.edu/~daniele/vub/VubB0Bch.xls
Just in case you want to play with it...
Daniele
>
> Hi all,
>
> we have a preliminary calculation of the the ratio
>
> R = BR(Bch->Xulnu)/BR(B0->Xulnu)
>
> R = 0.69 +- 0.17(stat) +- 0.12(syst) (0.69 +- 0.21)
>
> Below you can find the detailed information including the correlation
> (between B0 and B+) assumed for each term. Few systematic uncertainties
> have to be recomputed separately in order to have a more precise
> calculation of the syst error.
>
>
> Daniele and Riccardo
>
>
>
> V_ik = Vuncorr_ik + Vcorr_ik
>
> Vuncorr_ik = sigma_i * sigma_k * delta_ik
> Vcorr_ik = sigma_i * sigma_k
>
> Stot = sqrt( Sum_ik (D(ratio)_i D(ratio)_k * V_ik) )
>
>
> =============================================================================
> Effect SYS B+ SYS B0 corr(C) or uncorr(U)? redone?
> =============================================================================
> stat 18.1% 17.4% U
> MC stat 8.5% 6.5% U
>
> ele ID 1.6% 0.8% C
> mu ID 5% 5% C (no fit, just a guess)
> K ID 3.8% 1.9% C
> tracking 0% 0.8% C
> neutral 4.7% 3.4% C
> breco 3.8% 3.8% U *
> binning 2.9% 2.9% U *
> eps_t ratio 4% 4% U *
> B_D 8.6% 2.6% U
> Excl b->u 2.7% 2.7% C *
> Incl b->u 1.1% 4.8% C
> had 3% 3% U *
> fermi 18.8% 15.8% C *
>
>
> The central values are
>
> B0 BRBR = 0.0245504 +- 0.00428074(stat) +- 0.00161026(MC stat)
> Bch BRBR = 0.0168213 +- 0.00304205(stat) +- 0.00143939(MC stat)
>
>
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