Re: [BLAST_ANAWARE] ed elastic Vector Asym

From: Chi Zhang (zhangchi@MIT.EDU)
Date: Sat Mar 27 2004 - 23:13:12 EST


Hi, Pete,

the cuts on beta and momentum are beautiful. nice work, seems you are ahead of
me on ed now. Are the beta's out of can from reconstruction or did you do your
own calculation?

Chi

Quoting Peter Karpius <karpiusp@einstein.unh.edu>:

> Hello all,
>
> After some help from Vitaliy last week I borrowed (stole) and
> modified the QE vector asymmetry code for ed elastic, I am able to now
> provide some preliminary results. They are as follows:
>
> Attached are three plots:
> 1) VAsym for RUNS 4871 to 5676 (most 2004 ABS D2 minus junk runs etc)
> 2) VAsym for RUNS 5335 to 5676 (i.e. PHYS6 prescaled data and
> newphys_no_C2TOF.settings data)
> 3) VAsym for 5836-5879 (i.e. new runs with proper trigger and holding
> field)
>
> The green lines in the scatter plots represent momentum, beta, and
> timing cuts that I made in addition to the usual vertex, charge, tof
> combo etc cuts. The red and blue blobs are then the deuterons as can be
> seen by a rough calculation using beta and momentum.
>
> Please note the following:
> 1) The theory curve was produced using the relation
> A = sqrt(3/2)*cos(thetastar)*T10 - sqrt(3)*sin(thetastar)*cos(phistar)*T11;
> which is obtained from Donnelly & Raskin (1986) [eqn 3.13b, 3.16a, 3.16b]
> (*** ALSO NOTE that we are checking the above numerical factors ***)
>
> 2) Note that the polarization is taken as 100% so that the Fano tensors
> f^(i)_1 in [3.16] are 1/sqrt(2) (also using the convention of
> Edmunds for associated Legendre polynomials).
>
> 3) The target angle is set to 20 deg in the first two plots and to 45
> degrees in the last plot.
>
> 4) The theory curve was produced using TGraph in Root so it is more of a
> smooth curve through the points produced by using T11 and T10 (of John's
> proposal -> Zilu's thesis & Arenhovel) rather than an actual fit.
>
> The next step is to continue this check of the formalism and also
> do an actual fit the data (using TMinuit?) and the theory and make my own
> determination of the dilution. (hopefully after we get a ton of data at 45
> degrees)
>
>
> Pete
>
>
>
>
> ----------------------------------------------
> Pete Karpius
> Graduate Research Assistant
> Nuclear Physics Group
> University of New Hampshire
> phone: (603)862-1220
> FAX: (603)862-2998
> email: karpiusp@einstein.unh.edu
> http://pubpages.unh.edu/~pkarpius/homepage.htm
> ----------------------------------------------
>
>
>
>
>
>



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