JUPITER
:  Jlab Unified Program to Investigate nuclear Targets and Electroproduction of Resonances: (old 2003 Web Page of P03-110)

For latest 2004 JUPITER Web of E04-001 see:
(http://www.pas.rochester.edu/~bodek/jlab/JUPITER.html)

P03-110  2003 related links

PAC24 Presentation Tuesday June 17, 2003 see:

Related Experiments see: http://www.jlab.org/exp_prog/experiments/

E03-110 Jlab-Technical-Review  and Jlab Theory Review (Below)

Proposal Number: P03-110Hall: C

Title: Measurement of F2 and R=  sL/ sT on Nuclear Targets in the Nucleon Resonance Region
Contact person: Arie Bodek (Rochester) and Thia Keppel (Hampton Univeristy)
Beam time request:

Days requested for approval: 5 days

Tune up included in beam line request: no

Beam characteristics:

Energy: 1.18, 2.29, 3.41, 4.52, 5.64, GeV and 1.64, 4.04 GeV

Current: 30 - 80 m A

Polarization: no

Targets:

Nuclei: 4 cm LH2, LD2, A1(MT),  C, Fe, Cu, Au, Si, Ca, Quartz, (possibly H 20)

Rastering: nominal
Polarized: no
Spectrometers:

HMS: single arm mode

SOS: single arm mode

Special requirements/requests: none

1) The experiment is technically doable, as proven by the previous E94-110 experiment, a similar measurement on the proton. In addition, experiment E99-118 has performed similar measurements on nuclear targets in the region of W2 ~ 5 GeV2, with far worse particle identification, charge symmetric background, and radiative correction problems.

2) The experiment is an add-on to approved experiment E02-109 that performs similar measurements on a deuterium (and A1 dummy) target. No overhead, apart from target changes, is included in this experiment, as it is assumed that the additional targets can be added either to the cryogenic target ladder, or to a standalone nuclear target ladder.

3) If the experiment would be scheduled separately from E02-109, the overhead for this experiment would amount to an additional 5-6 days, not requested, including one energy change and five pass changes.

4) As this is an L/T separation, many beam pass changes are required, and an additional one (major) linac energy change. However, as mentioned, these energy changes are compatible with the previously approved E02-109.

5) The experiment assumes some unconventional targets such as Si, Ca, and Quartz, and further more mentions it will investigate adding a water target.The choice of these targets is guided by targets/detectors used in neutrino physics experiments. Although none of these targets are impossible, some care would need to be taken.E.g., the final current allowed by some of these depends strongly on the thermal contact with external active or passive cooling (as also mentioned in the proposal), the Ca target should be kept in oil as it reacts with air (such a target has been used before in Hall C), and possible inclusion of a water target seems non-trivial.

6) The estimated uncertainty in  D RA is not given, but is presumably similar as the estimate of D RD of E02-109: 0.03-0.05.To reach such precision in an experiment accessing a wide range of rates in the detectors is difficult, although conditions are easier than in E99-118.The achieved uncertainty of E99-118 should be shown.

7) The experiment does include some overhead for investigation of charge symmetric backgrounds and radiative corrections.

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Theory TAC Comments - PR-03-110
PR~03-110}: Measurement of $R=\sigma_L/\sigma_T$ on nuclear targets in the nucleon resonance region}
( Van Orden and Richards )}
This work has the potential to provide substantial input that would aid in the understanding of neutrino oscillations.
Understanding this effect is essential to the physics of the standard model. This is clearly an opportunity to contribute to a topic of fundamental importance.

PR 03-110 Klein*, Kuhn
PAC24 Members

FRITZ KLEIN

Physikalisches Institut
Universität Bonn
Nussallee 12, 53115 Bonn
Germany
Phone/Fax: 49 228 73 2341/7869
klein@physik.uni-bonn.de
http://lxsa.physik.uni-bonn.de/~klein/

SEBASTIAN KUHN
Old Dominion University
Dept. of Physics
1021-47th Street
Norfolk, VA 23529
Phone/Fax: (757) 683-5804/5809
skuhn@odu.edu
http://www.physics.odu.edu/~kuhn/Default.html

Questions from Kuhn

Dear Thia,

as you know, I am the secondary reader for your new PAC proposal 03-110. Since  time is getting short for your preparation for the PAC meeting, here some
preliminary questions/concerns I have about your proposal. If you want to meet  in person to discuss these issues, I should be available sometime next week.
However, I would also appreciate an email response.

1) Obviously, this proposal is related to similar experiments already approved  or even completed. In particular, some results from 99-118 and how they relate  to the proposed program would be interesting. Is there any overlap (or could  there be) with PR03-103? (J. Arrington, spokesperson)

2) In a similar vein, could you address the question "what do we learn from this  wide variety of nuclear targets (some quite unconventional, for sure) that we  cannot learn from a careful comparison of just a few 'pure' species, e.g. C, Al  and maybe Fe?" My naive assumption would be that R_A is approximately equal to  R_D (plus Fermi smearing), and if there is an EMC-type effect, it should be  quantifiable by studying a few denser/heavier nuclei. I'm worried about the  overhead of all these target changes.

3) In general, I believe it would be good to have a clear and detailed expose of  the INTRINSIC Physics value of your proposed measurements (what will we learn  about nuclei, QCD, nuclear corrections, the EMC effect... that we don't know  already) as opposed to just the neutrino-related justification. Can you show us  a comparison of the expected data (with statistical and systematic errors) on a  plot like Fig. 1? Maybe even with expected error bars from 99-118?

4) Regarding the Al target: Do I read your table II correctly that seems to say  that you'll spend a lot more time on Al than all other target types? I realize  this is part of E02-109, but couldn't one shorten this time by using thicker Al  targets?

5) I also would like to get a clearer idea of the value of the proposed data in  relationship to the neutrino experiments. Do you need the measured R values as  INPUT to analyze nu experiment? In that case, can you show the impact of these  proposed data on nu data (how much does their systematic error due to lack of  knowledge of R shrink)? Or do you argue that these data can be COMPARED with nu  ones? In that case, can you give us an idea of what this comparison would look like (what quantities can one extract or tests apply? With what confidence level?)

Greetings - Sebastian
---------------------------------------------------------------------------------------

Email 2:

Date: Tue, 10 Jun 2003 12:36:32 -0400
From: Sebastian Kuhn <skuhn@odu.edu>
To: Cynthia Keppel <keppel@jlab.org>
Cc: F. Klein <klein@physik.uni-bonn.de>
Subject: Re: response to PAC reader questions

Hi Thia (and Arie),

thanks for your very detailed answers to my questions. I will ponder them some more and look at the updated version of your proposal. Unfortunately, it may be
hard to get together to discuss these issues in person before the PAC meeting due to all the other events going on this week (which I am heavily involved in).
However, I'll be certain to try to contact one of you if there are remaining questions after your presentation.

I had a quick look at some of your slides. I guess (to reiterate my main points) what I really would like to see are "predicted pseudo-data" together with
existing (preliminary) results from SLAC and JLab, including 99-118. I realize that the kinematic region is different, but it is much easier to visualize the
impact these new data would have if they could be plotted vs. some reasonable model predictions for R (maybe even several) in nuclei. Correspondingly, it
would also be nice to see a plot of some quantities extracted from neutrino scattering (e.g. sum rules, moments, duality tests,...) with the systematic error that one
would get WITH and WITHOUT the knowledge these new data will provide. I realize that all of this hangs together and each piece of information
is valuable (for better models etc.), but it's always better to be quantitative (or at least illustrative).