BLAST gc gq (fwd)

From: Chi Zhang (zhangchi@mit.edu)
Date: Thu Sep 08 2005 - 00:13:25 EDT


Hi all

I would like to share some new results from BLAST ed elastic, the GC and
GQ obtained from tensor asymmetries measured at BLAST. see the atatched
figure. If people want to show this PRELIMINARY result in their conference
talks, I will provide plots in required format.

Here is some detail about the result:

Abbott 1 is refitted with BLAST tensor and vector results. BLAST Asymmetry
data and A(Q) interpolated using the Abbott fit are fitted at each Q2
point by varying GC and GQ. A(Q) is obtained from the above Abbott 1 fit.
B(Q)(or GM(Q)) are also fixed by the above Abbott 1 fit. All systematic
errors are included in the fit. As expected, I was not able to obtain good
results varying GM at the same time.

Preliminaryly, BLAST data confirms the first node of GC at
4.172+-0.042 fm-1 compared to 4.21+-0.08 fm-1 obtained from data up to
JLAB 2000, and in agreement with VEPP-3 2003 PRL value. VEPP-2 2003 PRL
listed first node at 4.173+-0.038fm-1. the seeminly smaller error they
quoted could be due to the fact that they fitted Abbott 1 by only varying
the first node position leaving all other 17 parameters fixed while I did a
full 18 parameter fit.

The error bars in GC and GQ reaches a largest value at arround 3 fm-1 and
then shrink down again going to higher Q values. I do not fully understand
this behavior yet. But this trend in error size is also seen in VEPP-3
results, so I think it is a "feature" not a bug. :)

Enjoy.

Chi




This archive was generated by hypermail 2.1.2 : Mon Feb 24 2014 - 14:07:32 EST