Dear Diego,

General comment:
As the uncertainty still depends on the simulations, I wonder if we have
other ways to check the systematic accuracy than by simulations.
And if we fully trust the simulations, cannot we have a sample of extremely
delayed decays above t = 6 ps by skipping in the track simulations the
decays within t = 6 ps? This would improve the acceptance slope determination.

Abstract:
Replace "is determined ... agreeing with original theoretical predictions"
by "is determined ... and agrees with theoretical predictions"
In the "original phenomenological analyzes ... do not lead to differences
among the meson lifetimes" according to [22].

Line 18:
Replace "have indicated that a higher value is likely [13]"
by "indicate that a higher value is more likely[13].

Line 19:
Replace "In fact, the previous LHCb measurement agreed with ... expectations [14]" 
by "Our previous LHCb measurement [14] agrees with ... expectations".

Line 22-25:
- Replace "Here ... together" by
  "Here we analyze the new 2.0 fb-1 data sample at 8 TeV and the previous
  1.0 fb-1 data sample at 7 TeV combined".
- Replace "Simulations use a larger event sample ... and uncertainties are"
  by "The simulation analysis uses a larger event sample ... and the
  systematic uncertainties are".

Line 29:
Replace "thus facilitating cancellation of systematic uncertainty" by
"which reduces the systematic uncertainty".

Line 143:
Replace "t, is defined as t = m bold d . bold p / |bold p|2" by
"t, is reconstructed as t = d / gamma beta c = m bold d . bold p / p2"