[esa-t474] [Fwd: esa-t474 post from drw1@hep.phy.cam.ac.uk requires approval]

[Bino Maiheu]

Hi All,

I'm forwarding a bounced mail from David to the T474 list.

This beam strahlung issue is indeed important, maybe we could mention
something in the introduction, but for sure a detailed is *far* beyond
the scope of this paper, and leans more closely to a future spectrometry
paper.

Cheers,
     bino


-------- Forwarded Message --------
From: David Ward <drw1 at hep.phy.cam.ac.uk>
To: Mark Slater <slater at hep.phy.cam.ac.uk>
Cc: esa-t474 at hep.ucl.ac.uk
Subject: Re: [esa-t474] Your submission (fwd)
Date: Fri, 14 Dec 2007 11:45:11 -0000 (GMT)

Hi Mark,

     Probably Stew understands this more deeply than I do.  Beamstrahlung
(and ISR) shifts the collision energy downwards, but there's still a sharp
peak at the full energy.  And for things like threshold scans, it is
crucial to know the maximum energy, because this matters most in
determining how the cross-section turns on.  Measuring the luminosity
spectrum (i.e. the shape of the beamstrahlung/isr curve) is a separate
issue, addressed by (for example) Bhabha acollinearity - see the old paper
by Frary and Miller.

Cheers,

     David.

> Dear All,
>
> Here are the first comments from the reviewer. Does anyone have a good
> answer to this?
>
> Thanks,
>
> Mark
>
> ---------- Forwarded message ----------
> Date: Thu, 13 Dec 2007 21:08:00 -0000
> From: nim at lbl.gov
> To: slater at hep.phy.cam.ac.uk
> Subject: Your submission
>
> Nuclear Inst. and Methods in Physics Research, A
> Title: Cavity BPM System Tests for the ILC Energy Spectrometer
>
> Dear Dr. Slater,
>
> Thank you for your recent submission to Nuclear Inst. and Methods in
> Physics Research, A.
>
> Before proceeding further with the review process, I would like you to
> address in detail the following issue.  Beamstahlung will spread the
> energy of the electrons and positrons at the collision point by an amount
> far greater than the precision of the instrument that you propose. Indeed,
> for the purposes of data analysis new approaches, such as particle flow
> analysis, must be developed because one cannot balance momentum in the
> beam direction. Your treatment of this issue should speak to how the
> information from the proposed instrument would be used as an input to the
> new physics analysis approaches.
>
> Sincerely,
>
> William A. Barletta
> Editor
> Nuclear Inst. and Methods in Physics Research, A
>
>
> _______________________________________________
> esa-t474 mailing list
> esa-t474 at hep.ucl.ac.uk
> https://mail.hep.ucl.ac.uk/mailman/listinfo/esa-t474
>


email message attachment
-------- Forwarded Message --------
From: esa-t474-request at hep.ucl.ac.uk
Subject: confirm 5d02ecda06de45978ceae29e7f341d333b68415a

If you reply to this message, keeping the Subject: header intact,
Mailman will discard the held message.  Do this if the message is
spam.  If you reply to this message and include an Approved: header
with the list password in it, the message will be approved for posting
to the list.  The Approved: header can also appear in the first line
of the body of the reply.
-- 
                                                  !!!!!
                                                 ( o o )
          @ -- Bino Maiheu, Dr. ;) ---------oOO----(_)----OOo------- @
         /  :: WORK                .::  /  :: HOME             .::  /
        /  University College London   /                           /
       /  Physics and Astronomy       /  31 Kilgour Road          /
      /  Gower Street                /  Forest Hill              /
     /  London WC1E 6BT             /  London SE23 1PG          /
    /  [tel] +44 20 7679 3454      /  United Kingdom           /
   /  [fax] +44 20 7679 7145      /  [mob] +44 7747 75 58 78  /
  @ -------------------------------------------------------- @