RE: [BLAST_ANAWARE] ed elastic asymmetry day by day.

From: Ricardo Alarcon (RICARDO.ALARCON@asu.edu)
Date: Fri Jul 25 2003 - 10:08:55 EDT


Hi All,

I would like to comment on the plots Chi generated for the day by day
asymmetry.

1) We should try to plot these asymmetries in one single plot, asymmetry
versus time. If the distribution is not gaussian then there are systematics
problems.

2) About flipping: are we convinced that the spin states are read out
properly? If so, we should go back to flip the target much more often. This
could take care of some intensity problems on the different spin states.

3) On the other hand Tancredi just sent evidence that there is not much
spin-dependent normalization.

Anyway, to do 1) is important (run by run is even better). We did this in
early June when we were running polarized hydrogen and found a very nice
gaussian (Baris has this plot).

Cheers,

Ricardo

-----Original Message-----
From: zhangchi [mailto:zhangchi@general.lns.mit.edu]
Sent: Thursday, July 24, 2003 8:43 PM
Cc: Blast_Anaware
Subject: [BLAST_ANAWARE] ed elastic asymmetry day by day.

Hi, all,

please take a few of your precious moments to board on a time travel with
me. :)

atatched are figures for ed elastic tensor asymmetries from runs taken on
different days.

1st, please see ed_asym_bf_7_13.eps: before July 13th when we were running
cycle 3 automatic flipping. blue dots are data, the 2nd and 3rd are the
significant ones. red curves are theory with 100% polarization. left is
parallel kinematics and right is perpendiculare kinematics

It looks OK, even promising. at least one can scale the theory curve down
to touch the error bars and both sides are at least consistant.

2nd. please see ed_asym_7_13_7_16.eps: from July 13th to July 16th. We are
running manual flipping in T20 sequence. Cell tempreture control was not
working, had to turn on and off the heater by hand, so cell temp varied
quite a bit, tipically 95-105, could be as large as 85-115. Still OK,
parallel kinematics shows even better trace of T20. If one scales the
theory curve to data, at least tow sides are consistant.

3rd. please see ed_asym_7_16_7_17.eps: OH boy, this is a thrilling
picture! tempreture control started to work, temp varied run by run a
little and was rather stable during single runs. Both data points in
parallel kinematics distinguish from 0 and has damn right Q squared
evolution. perpendicular side is consistant with the left and the second
dots is positive already.

4th. please see ed_asym_7_18.eps: data on July 18th. everything crapped
out. nothing makes sense. If you look at the ligit vs. run# plot Tancredi
sent earlier today, this is about where the ligit shot up to 0.12.

5th. please see ed_asym_7_19.eps, ed_asym_7_20.eps, ed_asym_7_21.eps.
Very depressing, seems I am never gonna make it to my graduate day.
For 3 days, data points seem to be wherever they want to be. for this
part, the ligit dipped down to 0.08 and climbed slowly back up to 0.1.

6th. please see ed_asym_7_22.eps, on 22nd. still, I say, results are not
good. but on can argue that it seems things are back on track. At least,
all points are close to where they are expected.

After that, we stopped for unpol.

Any comments, any one? I don't what to say. I hope to hear from target and
analysis experts.

Chi



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