[Clascomment] OPT-IN: Measurement of the Spin and Parity of the Lambda(1405)

[Reinhard Schumacher]

Hello Elton,

	Here is what we did with your suggestions.  See below.

Cheers,
Reinhard

___________________________________________________________________
Reinhard Schumacher         Department of Physics, 5000 Forbes Ave.
Carnegie Mellon University, Pittsburgh, PA 15213, U.S.A.
phone: 412-268-5177         web: www-meg.phys.cmu.edu/~schumach
___________________________________________________________________

On 11/06/2013 03:33 PM, Elton Smith wrote:
> Comments to Measurement of the Spin and Parity of the Lambda(1405)
>
> Great paper, very readable with a nice result.
>
> Abstract: Suggest : A determination ->  A measurement
>
didn't want the repeat the word already used in the title.

> 9: The Lambda(1405) IS a peculiar state….
>
no change since we want to emphasize the long-standing nature of this 
state's structure puzzle.

> 22: …difficult in identifying the mass ->  difficulty in classifying?
>
maybe, but not quite.  We changed to "..in computing the correct mass..."

> 105: …Y*->Y pi, the parity can be found by measuring Q, which determines L.
>
Hmm... yes, that sentence is not so elegant.  We changed it to read:

Since the parity of the $Y^{\ast}$ is determined by the orbital angular 
momentum $L$ of the decay $Y^{\ast} \to Y \pi$, and since a measurement 
of $\vec{Q}$ determines  $L$, the parity can be found.

> Figure 2 a) The contribution to the Y*(1670) is almost invisible, which becomes a little confusing since the Lambda(1405) is of essentially the same color. You might be able to fill in the Y* histogram with a light color (e.g. yellow), which would make it visible. It would also make the histogram consistent with other contributions.
>
We have played a lot with this figure to make the small contributions 
(and they really are small) show up well.  In the end we have what is 
now in the paper, and we decided not to tweak it any more.

> Paragraph 211-230. You might want to give the Chi2 values for various fits (see below).
>
The actual numbers for these values are not so interesting, we think, 
which is why we restricted the discussion to qualitative statements and 
giving numbers of "sigmas".  When the alternative hypotheses are ruled 
out so decisively, the exact numerical values of the probabilities are 
not what people are going to want to see.  We decided that giving the 
detailed numbers for the rejected hypotheses would not be any more 
convincing to the readers than what we have now. If you want to see the 
tabulated values of those numbers, there is an analysis note that lists 
them all.


> Summary and conclusion: 283-299:
> The first sentence (spin parity is most consistent with 1/2-) is rather tepid and I think the data
can allow a more forceful conclusion. You might be able to make a more 
quantitative statement regarding
the preference of the data for the 1/2- assignment if you give the Chi2 
values for various hypotheses in
paragraph 211-230. From the Chi2 one can derive a probability for each 
hypothesis. In other words, it
would be nice to conclude with something like: The probability for the 
1/2- assignment is great than …
times the probability than other alternatives considered (1/2-, 3/2+-).
>
We have strengthened the wording in the last paragraph in response to 
comments by other people, but for reasons mentioned above we decided not 
to dwell on these numerical details when recapitulating our main conclusion.