[esa-t474] Your submission (fwd)
Mike Hildreth
mikeh at omega.hep.nd.edu
Thu Dec 20 02:46:03 GMT 2007
I agree as well... Clearly, the review/editor didn't pay attention to ISR
issues at LEP, either...
cheers,
mike
On Wed, 19 Dec 2007, Yury Kolomensky wrote:
> I would agree with Eric. We can add a paragraph describing the impact of beam
> energy measurement and other techniques to determine the spectrum that help
> turn this into a physics tool. There is a sentence and a reference now;
> expanding this to a paragraph would be sufficient. I think we can safely claim
> that no other measurement can compete with precision. In the letter to the
> editor, we can point out that this is the paper about instrumentation, not a
> physics publication, so more detailed discussion is beyond the current scope.
> It is even beyond the scope of the next paper.
>
> Yury
>
> On Dec 19, 2007, at 7:59 AM, Eric Torrence wrote:
>
> >Hi Stewart,
> >
> > I would try to argue to the editor and reviewer that
> >the topic of this paper is a measurement of beam energy.
> >The reviewer is correct in saying that there are other
> >issues regarding the use of this device in the ILC to
> >measure root(s) spectrum, but this is not the topic of
> >the current work.
> >
> > This is NIM after all. When people write papers on
> >drift chambers, they don't explain in detail what kind
> >of physics measurements they are going to do with them.
> >
> > I would think that one intro paragraph (at most)
> >discussing these issues in the broadest terms should be
> >adequate.
> >
> >Regards,
> >-Eric
> >
> >On Dec 18, 2007, at 2:42 PM, stewart boogert wrote:
> >
> > >Dear Eric, Mark and T474,
> > >
> > >The reviewers comments are quite interesting and all quite beyond the
> > >scope of the paper, which is principally machine physics.
> > >
> > >1) The peak of the spectrum is the most important feature with regards the
> > >physics program. The luminosity spectrum at the collision point bounded at
> > >the
> > >top by the spectrometer measurement. In fact for M_t and M_h this is the
> > >most important
> > >feature. The effect of the luminosity spectrum is convoluted with the
> > >threshold structure
> > >being investigated, so the large energy loss beamstrahlung events are
> > >suppressed and
> > >only the peak really contributes.
> > >
> > >2) Absolutely no physics measurement (particle flow, or even more exotic
> > >for
> > >any physics process ) can provide a precision energy measurement at any
> > >reasonable time scale. It is possible to measure the beam energy using
> > >radiative returns to the Z but this analysis is incomplete and provides
> > >energy
> > >measurements at similar frequencies to physics rate.
> > >
> > >3) The measurement of Bhabha scattering can provide information on
> > >the momentum imbalance between the two colliding beams on a more rapid time
> > >scale, but this method as formulated in all treatments does not reconstruct
> > >the collision
> > >centre of mass energy, only the fractional energy loss from the maximum
> > >beam energy.
> > >Of course then one requires the energy spread of the machine too. From
> > >Bhabhas the momentum
> > >mismatch between the beams \Delta p can be measured not what p actually is.
> > >
> > >4) I would think that more important comments are that the energy loss from
> > >the measurement
> > >location and just before collision are more important as it is quite
> > >difficult to measure this
> > >effect. Bino is simulating now, but we do not yet know the answer.
> > >
> > >I can definitely add come text to the paper to this effect if the reviewer
> > >agrees.
> > >There is little published in this area, something Eric. Mike and I have
> > >been trying
> > >to correct for a while but without success.
> > >
> > >I'll add a little more text to Mike's paragraph in a few hours and send
> > >around.
> > >
> > >Cheers,
> > >Stew
> > >
> > >
> > >On 14 Dec 2007, at 18:02, Eric Torrence wrote:
> > >
> > > >Hi Mark,
> > > >
> > > > I think Mike has already given some good pointers
> > > >on this, but just to reiterate it should be clearly
> > > >stated that measuring the mean beam energy before
> > > >collisions is a necessary (but certainly not sufficient)
> > > >part of determining the collision spectrum needed for
> > > >the ILC program. For both direct reconstruction like
> > > >M_H and threshold scans like M_t, the peak of the
> > > >spectrum is the most important feature. There are
> > > >plenty of corrections, including energy loss in magnets
> > > >and beamstrahlung, which need to be applied, but without
> > > >a calibrated mean beam energy measurement you have no hope.
> > > >
> > > >Regards,
> > > >-Eric
> > > >
> > > >On Dec 14, 2007, at 3:18 AM, Mark Slater wrote:
> > > >
> > > > >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
> > > > >
> > > > >
> >>>>_______________________________________________
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> > > > >esa-t474 at hep.ucl.ac.uk
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> > > > >
> > > >
> > > >
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