[d2n-analysis-talk] Projected A1n Statistical Errors [Updated]

[David Flay]

Hi all,

Utilizing the parameterization that I showed previously, I've calculated
the resulting (statistical) error bars on A1n.  Until the highest x
values, the error bars are better than ~2--3%.  The largest error occurs
at x ~ 0.8, where the error is ~11%.  Concerning the overlapping x region
with E99-117, our statistical errors are (at least) of comparable size
with their statistical errors (taking a quick look by eye).

The updated plot (showing 5-pass errors only; 4-pass gets quite ugly at
high-x, in the range of > 10%) is here:

http://www.jlab.org/~flay/thesis/A1_error/plots/A1n_proj-stat-error_10_27_10.pdf

To show how the R value was determined, below you'll find a few tables
I've constructed from the parameterization I showed last time (from the
fit to the data showed in Xiaochao's thesis).

Note that R is calculated from Rnp using:

R = Rnp/(Rnp + 2.0)

The labels 4- and 5-pass are only used to distingush the differing x-values.

Rnp (4-pass):
x = 0.21400, Rnp = 0.77418
x = 0.30000, Rnp = 0.69770
x = 0.34700, Rnp = 0.65937
x = 0.46300, Rnp = 0.57360
x = 0.50100, Rnp = 0.54786
x = 0.54200, Rnp = 0.52124
x = 0.63300, Rnp = 0.46587
x = 0.69200, Rnp = 0.43236
x = 0.75400, Rnp = 0.39886
x = 0.82800, Rnp = 0.36085
Rnp (5-pass):
x = 0.20800, Rnp = 0.77985
x = 0.28900, Rnp = 0.70701
x = 0.33100, Rnp = 0.67217
x = 0.43600, Rnp = 0.59254
x = 0.47000, Rnp = 0.56878
x = 0.50500, Rnp = 0.54522
x = 0.58400, Rnp = 0.49508
x = 0.63300, Rnp = 0.46587
x = 0.68500, Rnp = 0.43625
x = 0.74500, Rnp = 0.40362
R (4-pass):
x = 0.21400, R = 0.27907
x = 0.30000, R = 0.25863
x = 0.34700, R = 0.24794
x = 0.46300, R = 0.22288
x = 0.50100, R = 0.21503
x = 0.54200, R = 0.20674
x = 0.63300, R = 0.18893
x = 0.69200, R = 0.17775
x = 0.75400, R = 0.16627
x = 0.82800, R = 0.15285
R (5-pass):
x = 0.20800, R = 0.28054
x = 0.28900, R = 0.26118
x = 0.33100, R = 0.25154
x = 0.43600, R = 0.22856
x = 0.47000, R = 0.22142
x = 0.50500, R = 0.21421
x = 0.58400, R = 0.19842
x = 0.63300, R = 0.18893
x = 0.68500, R = 0.17907
x = 0.74500, R = 0.16792

I will incorporate all of this info into the tech note concerning the
statistical errors.

-------------------------------------------------
David Flay
Physics Department
Temple University
Philadelphia, PA 19122

office: Barton Hall, BA319
phone: (215) 204-1331

e-mail: flay at jlab.org
            flay at temple.edu

website: http://www.jlab.org/~flay
              http://quarks.temple.edu
-------------------------------------------------