Some consideration on h/H/A ->tau tau (xs * BR)
This is a typical case where the YR does not give the answer in terms of explicit numbers, but in the form of a procedure that should be followed: input, central values, THU and PU and scale errors with combinations.
We do not think that there is a case for tabulating all XS*BR, users can do that. It is practically impossible to tabulate the full set of results in MSSM, unless one represents typical (M_A, tan(β)) points (which is not so useful).
That being said, we recommend the following:
2a) As far as the PDF error is concerned, the simplest way out is to determine the PDF error on the sum of different production mechanisms (in the usual way), rather than on each of the cross sections separately. Then the correlation is automatically taken into account. (comment by S. Forte)
2b) Therefore, in combining ggF and bbH one has to take into full account one caveat: since the b-PDFs so far are only contructed as being purely perturbative, i.e. fully generated by g -> bb spitting at LL level, a sum of the PDF uncertainties - linear as well as quadratic - seems to double count the gluon PDF uncertainties. Thus, one would prefer a scheme in which the PDF uncertainties of the sum ggF+bbH are computed as those to a single observable. The situation will only become different once there are data on b-PDFs... Noone knows until now if there is a non-perturbative intrinsic b contribution or not, i.e. whether the non-perturbative component is sizeable or not. We believe that 4-5 GeV as the input scale is deep in the perturbative regime. (comment by M. Spira)
2b) To summarize: we recommend to do once the check 2a) and compare the result with the simple addition in quadrature: it could well be that even though in principles the g and b are correlated, in practice the simple sum in quadrature works well. (comment by S. Forte)
3) Typically we vary scales in some range (like M_H/2 to 2M_H), but we never start thinking about it as if that represents the true uncertainty. It only represents `the best we can do'. But this should be clear from the YR.
The scale variation follows the recommendation of Harlander/Kilgore. It serves as a conservative estimate of the scale dependence for this process. (comment by M. Spira and M. Warsinsky)
4a) SUSY-QCD corrections: Statements that SUSY-QCD corrections are just of this and that size cannot be made, because they strongly depend a) on the scenario, b) on the details how LO is defined.
To a): The variety of all scenarios is too large and rich for overall statements in the YR. To b): residual corrections typically are small (not like 30% or so) if LO is based on loop-corrected masses of the external Higgs particles and appropriate effective couplings.
4b) SUSY-QCD corrections:
Concerning the SUSY-QCD corrections to bbH: They are fully accounted for by the Δ_b terms (up to the per-cent level for the remainder). The situation is not completely clear for the 5FS. In the 4FS the residual corrections beyond the Δ_b terms are tiny so that the same should be expected in the 5FS, too. (comment by M. Spira)
5) Δ_b: We know exactly where to place Δ_b, so there is no uncertainty. Switching it on and off does not quantify any uncertainty. (comment by S. Dittmaier)
6) We do not quote large tables with all uncertainties in the YR since it would require a 2D-scan (and probably produced hundreds of pages). Instead we have put everything in root-files on the Twiki pages. The uncertainties can be accessed easily from there. In addition we had added the BRs to bbbar, tautau and mumu, so xsec*BR is accessible from there. (comment by M. Warsinsky)