Transcript Elke Aschenauer - Do we really need EIC?

Do we really need EIC/ELIC ?
EIC meeting, MIT, April 2007
E.C. Aschenauer
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Really nasty questions
Why is HERA turned off if this physics is so interesting
new injector was only 100MEuro
only 151 people from 32 Inst. signed is that big enough of
an community
Is a precision machine worth a 1000M$
Is there any discovery potential
What is left after HERA, COMPASS and QCD@LHC
Why not lining up with LHeC are measuring polarized
quantities really so important
If there is money only for one project in the next 10
years, would you be willing to give up on of the other,
RHIC-2, polarized 500GeV pp, 12GeV
EIC @ MIT April 07
E.C. Aschenauer
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Nasty Questions
Why will EIC keep it’s promise to measure DG(x) if
Rhic and Compass have not yet been successful
Why should extrapolating from EIC to LHC be better
than extrapolating from HERA to LHC
If the program can start only after 12GeV construction
is finished still interesting
What is the real interest from non-American groups
Is there enough machine expert person-power to do R&D
for EIC/ELIC and 12GeV upgrade as well as RHIC-2
The HERA-II Lumi-upgrade was quite a struggle, why
will 2ns bunch spacing not cause the same problems
EIC @ MIT April 07
E.C. Aschenauer
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Questions
Physics:
Fragmentation: why is analyzing the Babar and Belle data
not good enough
why should anybody be excited about a stamp collection
measurement of structure functions, like transversity and
friends
will we ever be able to correlate sivers really with Lq or Lg
DG(x) you measure is not what you need to get Lg
Why is measuring Jq and Jg not enough. Is it really
needed to separate all the individual contributions to the
helicity sum rule
Is there really a concept to get GPDs from all the
exclusive measurements
EIC @ MIT April 07
E.C. Aschenauer
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Questions
Detector / Accelerator:
You will be systematic limited; what is the strategy to
improve the nucleon polarization measurement
what is the indication that you will be able to build a
detector to measure the very low angle scattered electron
is a detector for (semi-)inclusive and exclusive physics
compatible
how big is fraction of pile-up events
Which Luminosity is really needed and achievable for $’s
what is the driving physics
Why are polarized electrons and positrons needed
Why you need He-3 if you have polarized p and d
EIC @ MIT April 07
E.C. Aschenauer
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