Comments on LHCb-PAPER-2014-67

Title:
Replace "structure" by "broad resonances".
A structure can be anything.

Abstract:
Replace "in the high transverse momentum region" by
"at high transverse pion momentum".

Line 131:
Replace "the lab frame" by "the centre of mass system".
A laboratory angle of 150 degrees would not fit in the
LHCb acceptance.

Line 143:
Add "mass difference" to "distributions".

Figure 3:
- Although RS and WS are explained in the text.
  it helps to understand the plots if these are written in full.
- Replace "empty" by "white". 
  An empty histogram is a flat line with zero entries.

Line 149, 157:
- Use consistently "combinations" for both RS and WS,
  instead of "events".

- It is only after comparison with WS that more events
than expected from random combinations show up visibly at
masses lower than (NOT "under") the sharp resonances.
Therefore, lines 157-162 should move to before "Furthermore . . .".

- It is not clear if the RS-WS distribution are fitted or if
both the RS and WS distributions are fitted simultaneously.

- The statement "It has been checked .. ." is not convincing.
Certainly not that WS should describe the combinatorial
background of the RS combinations.

Equation 1:
The numerator sqrt(Gamma(m)) is strange;
I expect Gamma(m)**2, or m_0 Gamma(m)**2 if I should believe John Libby.
(http://www-pnp.physics.ox.ac.uk/~libby/Teaching/2005/C4-JL-lecture2.pdf)

Best regards,
 Tjeerd