General remarks:
* It would be nice to reflect on the physical meaning of the observed values: Is the double ration expected to be close to 1? Does one learn anything w.r.t. factorization? Are other numbers in agreement with CKM factors?
* In the analysis the charm-hadron masses are constrained to their nominal value. For the background under the peak this might lead to biases to the observed mass. Has this been checked?
* In lines 64-66 an arbitration is is performed. Why is such arbitration done? A specific mass phase space is treated different than the rest. Why not assign the event to both decays, which is what would have been done if the D and Ds analyses would have been performed in seperate analyses?
Specific comments:
* line 5: How is the sentence " .. many decays at the percent level [1]" an example of the previous sentence?
* Figure 3: The axis label is too complicated.
* line 154: Has it been proven that the momentum scale is the dominant uncertainty in absolute mass and not e.g. the opening angle systematics in the Velo (e.g. length scale of the Velo)?
Typically for high mass low multiplicity decays (large opening angle) the p-scale dominates and for lower mass and high multiplicity decays (small opening angle) the Velo systematics.
* line 198-200: Was the most recent acknowledgment sentence used for the Yandex sentence?
groeten,
- Marcel