Elong-13-09-12

From HallCWiki
Revision as of 15:02, 13 September 2013 by Ellie (talk | contribs)
Jump to navigationJump to search

Adding QE Range

Frankfurt and Strikman's 1988 Azz

In their 1988 report on Hard Nuclear Processes and Microscopic Structure, Fig. 7.7 plots what appears to be Azz.

2013-09-12-fs-Azz-plot.png


I took this plot and super-imposed it onto a plot in a spreadsheet so that I could estimate points along the curve.

2013-09-12-fs-Azz-spreadsheet.png


Each of these points, with an uncertainty of ±0.01 on account of my estimating from a previous work without direct points, was then put into a graph in ROOT and fit with a 6th-order polynomial, <math>\sum_{n=0}^6w_n\cdot x^n</math>

2013-09-12-fs-Azz-fit.png

<math>n</math> <math>w_n</math>
0 -5.68296e+01 ± 1.22251e-02
1 2.46102e+02 ± 1.66137e-02
2 -3.51484e+02 ± 1.39410e-02
3 1.11641e+02 ± 1.11237e-02
4 1.63698e+02 ± 8.63783e-03
5 -1.48174e+02 ± 6.15266e-03
6 3.50491e+01 ± 3.63922e-03

This fit was written up as a subroutine for the b1 rates code. It also assumes that at x>1.425, Azz=1 and that at x<0.75, Azz=0. The b1 rates code was then updated to use the previous Kumano curves for x<0.75 and this new QE curve for x>=0.75.

Q2 Scan

Starting with x=0.5, 0.75, 1.0, and 1.25 and including the Frankfurt and Strikman plot for Azz in the Quasi-Elastic range, I scanned over Q^2 looking for the best rates that fall within the spectrometers' limits.

2013-09-13-shms x 050.gif


2013-09-13-shms x 075.gif


2013-09-13-shms x 100.gif


2013-09-13-hms x 125.gif

First Pass Results

This is still a work in progress (for example, the lowest x point in b1 moves a bit which is caused by fluctuations in F1 calculating the point) and I'll be continuing to look at different x points to perhaps make a smoother transition, especially where Azz goes from near-zero to very large values. But at the moment, here's a rates estimate for a potential measurement:

2013-09-13-azz measurement.png

--E. Long 15:51, 12 September 2013 (UTC)