Hi Chi,
how far away is the corrected Phillips NNLO+dGQ/(1+Q^2/M^2)^5 calculation
at 2fm^-1? Unfortunately, you did not give the Pzz's for the EFT in your
presentation of last week.
If the theories really start to converge, I would be inclined to rather
use them or one of them than a parameterization of T20 that is based
on fitting data that had the same problem like ours. This is particularly
valid where new data has been normalized to existing data. Or expressed
differently, if the T20 data that entered in Abbott's fit had used
different normalizations, Abbott's result would have looked different,
which is not the case for the theories (hopefully).
Would it make sense to use Phillips NNLO+dGQ/(1+Q^2/M^2)^5 and account for
the uncertainty at the normalization point at 2fm^-1 by evaluating the
error band of that theory like Dan suggested??
Regards,
Michael
On Sat, 14 Jan 2006, Chi Zhang wrote:
>
> Hi Michael and all
>
> Since the (1+Q^2/M^2)-5 correction puts both van orden and schiavilla close
> to Abbott's parameterization I, I would propose use Abbott I as THE
> normalization which was what I use originally. I switched to Abbott III a
> while ago with the arguement that it is the middle one of the three
> parameterizations and gave a higher value for Pzz.
>
> By using Ab I, we solve a few problems. 1. We do not need to rely on the Qd
> correction game while having very close results to theories after the Qd
> correction. who knows what will be invented before I got out of here. 2.
> Since later we refit Abbott I and use Abbott I to fix A(Q) in separation of
> GC, GQ, it would be more natural to use Abbott I all over. 3. the spin angle
> fit from Abbott I is 47.5 for 2005 setup which is slightly closer to the map.
> 4. Abbott I is also the one among the three that is closest to the middle of
> Bates and NIKHEF data points.
>
> We can discuss about how to revise the normalization uncertainty later.
>
> Chi
>
> On Sat, 14 Jan 2006, Michael Kohl wrote:
>
>> Dear Chi and collaborators,
>>
>> being back from Ohio I'd like to report to you a little from my meeting
>> with Dan Phillips. My seminar presentation on BLAST showing data from all
>> channels was very well received and seemed to impress people a lot.
>> You can find a pdf file of my talk on the Blast website at
>> http://blast.lns.mit.edu/PRIVATE_RESULTS/Ohio_Seminar_060110/
>>
>> It was satisfactory to see that renormalizing the theories for T20 with
>> (25.83-GQ(0))/(1+Q^2/M^2)^5 gives the most consistent T20 description among
>> all. We agreed that the so-renormalized EFT T20 curve should be considered
>> "the one". Also, it was highly appreciated the additional constraint on the
>> location of the node of GC set by BLAST.
>>
>> Dan kindly requested to indicate an error band for the calculation. One
>> thing is to estimate how accurate the Qd correction would be. We agreed
>> that you should vary M between 0.75 and 1.5 GeV for the scale parameter. In
>> principle, also the exponent could or should be subject to variation, say
>> 5+- 1 or 2 ... you should try it and possibly add the variances due to M
>> and the exponent in quadrature.
>>
>> The other uncertainties with the EFT calculation are the choice of the NN
>> potential (shown in Dan's talk at Bates of last January) and the MEC (in
>> particular pi-rho-gamma) considered in the current. Feel free to contact
>> Dan if you need additional calculations.
>>
>> The third point we discussed was the timeline for the paper. Dan
>> understands that the Qd renormalization is quite important for the
>> interpretation of the BLAST data and therefore plans to write a short paper
>> on the Qd correction (a brief report). He would be able do do this in
>> spring and finish this by May. We discussed wether this paper on the Qd
>> correction or the BLAST data should be published first.
>>
>> If the BLAST data is to be published first, we would probably use the above
>> Qd correction and quote it as "private communication". His subsequent paper
>> would be a justification in posterior ( ... and effectively appear like
>> fiddling the description of already-existing data).
>>
>> If Dan's brief report is published first, the BLAST paper could refer to it
>> when the curve is shown. Furthermore, the theory would appear to be more
>> predictive. Though the BLAST data would have triggered Dan's
>> reconsiderations, there is no fitting of data involved in the applied Qd
>> correction.
>>
>> Dan and I therefore agreed that the BLAST data be better published after
>> Dan's brief report. As the BLAST steering committee decided that a BLAST
>> hardware paper be published before any other physics paper, and as the
>> kinematic offsets for the reconstructed angle is in the process of being
>> understood, I don't see right now why we could not proceed like this. Let's
>> work out the final results and the paper first and then evaluate for how
>> long we are willing to hold it up once it's ready.
>>
>> Best regards,
>>
>> Michael
>>
>>
>>
>>
>> +-------------------------------------+--------------------------+
>> | Office: | Home: |
>> |-------------------------------------|--------------------------|
>> | Dr. Michael Kohl | Michael Kohl |
>> | Laboratory for Nuclear Science | 5 Ibbetson Street |
>> | MIT-Bates Linear Accelerator Center | Somerville, MA 02143 |
>> | Middleton, MA 01949 | U.S.A. |
>> | U.S.A. | |
>> | - - - - - - - - - - - - | - - - - - - - - -|
>> | Email: kohlm@mit.edu | K.Michael.Kohl@gmx.de |
>> | Work: +1-617-253-9207 | Home: +1-617-629-3147 |
>> | Fax: +1-617-253-9599 | Mobile: +1-978-580-4190 |
>> | http://blast.lns.mit.edu | |
>> +-------------------------------------+--------------------------+
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
+-------------------------------------+--------------------------+
| Office: | Home: |
|-------------------------------------|--------------------------|
| Dr. Michael Kohl | Michael Kohl |
| Laboratory for Nuclear Science | 5 Ibbetson Street |
| MIT-Bates Linear Accelerator Center | Somerville, MA 02143 |
| Middleton, MA 01949 | U.S.A. |
| U.S.A. | |
| - - - - - - - - - - - - | - - - - - - - - -|
| Email: kohlm@mit.edu | K.Michael.Kohl@gmx.de |
| Work: +1-617-253-9207 | Home: +1-617-629-3147 |
| Fax: +1-617-253-9599 | Mobile: +1-978-580-4190 |
| http://blast.lns.mit.edu | |
+-------------------------------------+--------------------------+
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