From: Hironori Ito (hito@rcf.rhic.bnl.gov)
Date: Tue Jul 08 2003 - 10:53:24 EDT
Hello. Here is what I know.
Ian Bearden wrote:
> Dear Collaborators,
> I have received the referee report from PRL for the High pt letter I
> submitted 2. July, which I enclose below.
> I have looked up the lecture notes by Kopeliovich (nucl-th/0306044)
> and have skimmed it, but not read it thoroughly yet.
> The basic idea is that Kopeliovich says that it is incorrect to use
> 42mb for the pp cross section and that one should instead use ~30mb
> . The reason is that, according to him, our trigger counters only
> cover abs(eta)<3 and therefore miss large rapidity gap events where
> no particles are produced at midrapidity.
>
> How do we respond to this?
> 1) We use the same as other collaborations, and thus can compare with
> them.
> 2) The primary thrust of our paper (in contrast to the other
> collaborations) is the Rcp, and the pp cross section does not appear
> here.
As you say in the other mail, we don't use our pp data. Hence, we
assume they (UA1 or Star) did right.
>
> 3)What was our dAu trigger? IIRC, it was the INEL L+R. I don't know
> the coverage off the top of my head, but I do believe that it was
> more forward than eta=3.
Trigger for dAu was INEL L+R. (At least, that is what I provided
to Claus.) We used 3 outer rings located along the beam line at 155cm,
416cm, 660 cm. The inside and outside radius of the rings are about
6cm and 12.7cm. (The most inner ring was not used because it is in our
way, but they still cover very large fraction of cross section. ) It is
obviously larger than eta=3.
Is there a "large" rapidity gap in dAu?
For my thesis, I investigated the effect of cross section to number of
participants and collisions. (See Fig 8.13 of my thesis). For AuAu,
changing the cross section from 40 to 30 mb decreases the number of
collisions by 23% for the most central events (I think it is for 0-5%
central events, but I did not mention.) Therefore, it will move Raa.
But, I think it is very wrong to use 30mb in this calculation.
Therefore, we are ok. The effect of cross section to the reference
spectra, we obviously don't know since we didn't measure it.
>
> 4) What other arguments do we have?
> My suspicion is that the 3 things I list are enough, but I wish we
> had something a bit more substantive.
> Best regards, and respond quickly!
> Ian Bearden
>
> 07Jul03
>
> Dr. I. Arsene
> bearden@nbi.dk
>
> Re: Transverse momentum spectra in ...
>
> By: Arsene,I. LG8974
>
> Dear Dr. Arsene:
>
>
> The above manuscript has been reviewed by one of our referees.
> Acceptance
> of your paper for publication seems likely, but we first ask you to
> consider carefully the enclosed comments.
>
> Please accompany your resubmittal by a summary of the changes made, and
> a brief response to any recommendations and criticisms.
>
>
> Yours sincerely,
>
> Jerome Malenfant
> Senior Assistant Editor
> Physical Review Letters
> Email: prl@aps.org
> Fax: 631-591-4141
> http://prl.aps.org/
>
>
> ________________________________________________________________________
> _______
>
> Report of Referee A:
>
> The Brahms collaboration reports in this paper results on high p_t
> charged
> hadron spectra from Au-Au and d-Au collisions. Different from all
> other RHIC
> collaborations the Brahms results are obtained both a mid-rapidity
> and forward
> rapidity (eta = 2.2). These results confirm and complement recent
> results by
> PHENIX and STAR: the suppression observed in high p_t hadron
> production for
> Au-Au collisions persists to forward rapidities, but is absent in d-Au
> collisions. For d-Au collisions, rather, a Cronin-type enhancement is
> observed,
> casting serious doubts on the interpretation of the Au-Au data in
> terms of
> initial state scattering. The paper is well put together and should be
> published without further delay. I have only the following comment,
> which the
> authors may want to consider:
>
> the use of 42 mb as inelastic cross section for NN collisions has
> recently been
> critized in nucl-th/0306044. Although this is not a published paper, the
> authors may want to comment.
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