Successful fits have now been performed with the unpolarized a2
data. We have fit the data weighted via Adam's routines with pwa2000, and
the results look reasonably good. Paul has a sample of 15744 "events"
which are fit with positive and negative reflectivity waves. At the
moment, the error calculator is not written, so he has been doing a
couple of simple things to try and estimate the errors. The first is
to just use the diagonal elements of the covariance matrix, which
is listed as the first error. The second is an effort to get an
upper limit on the error by simply adding all errors, rather than
adding in quadrature. The intensities for the two partial waves
should come out equal, but the errors are fairly large on them.
The results of the a2 are as follows:
nevents = 15744
a2p.u.amps intensity is 7841 (+/-1384 || 3718)
Total intensity = 15749 (+/-1984 || 7662)
As a continuation of the unpolarized study, Paul then added a1
waves to the fit. As these are not in the data, their intensities should
come out to be zero. He finds that the amplitudes for the a1
(shown in red) are all small as compared to the a2. However,
the reported errors are huge when compared to the values.
Calulating Intensities (+/- error-diagonal || error-upper-bound)
a2n.u.amps intensity is 7908 (+/-1421 || 3882)
| Ext No |
Parameter Name |
Parameter Value |
Approximate Error |
Step Size |
First Derivative |
| 1 | R_a2n.amps | 0.14108 | 0.43080E-01 | 0.10706E-03 | 0.32283E-01 |
| 2 | R_a2n.amps | 0.14108 | 0.43080E-01 | 0.10706E-03 | 0.32283E-01 |
| 3 | R_a1p.amps | 0.33712E-05 | 0.34688E-01 | 0.10073E-02 | 0.27855E-02 |
| 4 | R_a1p.amps | 0.33712E-05 | 0.34688E-01 | 0.10073E-02 | 0.27855E-02 |
| 5 | R_a1n.amps | 0.41978E-05 | 0.37300E-01 | 0.10839E-02 | 0.29995E-02 |
| 6 | R_a1n.amps | 0.41978E-05 | 0.37300E-01 | 0.10839E-02 | 0.29995E-02 |
| 7 | R_a1p.amps | 0.33712E-05 | 0.34688E-01 | 0.10073E-02 | 0.27855E-02 |
| 8 | R_a1p.amps | 0.33712E-05 | 0.34688E-01 | 0.10073E-02 | 0.27855E-02 |
| 9 | R_a2n.amps | 0.14108 | 0.43080E-01 | 0.10706E-03 | 0.32273E-01 |
| 10 | R_a2n.amps | 0.14108 | 0.43080E-01 | 0.10706E-03 | 0.32273E-01 |
| 11 | R_a2p.amps | 0.14038 | 0.43755E-01 | 0.10859E-03 | -0.65061E-01 |
| 12 | R_a2p.amps | 0.14038 | 0.43755E-01 | 0.10859E-03 | -0.65057E-01 |
| 13 | R_a2p.amps | 0.14038 | 0.43756E-01 | 0.10859E-03 | -0.65058E-01 |
| 14 | R_a2p.amps | 0.14038 | 0.43755E-01 | 0.10859E-03 | -0.65058E-01 |
| 15 | R_a1n.amps | 0.41978E-05 | 0.37300E-01 | 0.10839E-02 | 0.29995E-02 |
| 16 | R_a1n.amps | 0.41978E-05 | 0.37300E-01 | 0.10839E-02 | 0.29995E-02 |