27 May 2022

Calculate χ2 for your own experimental data.

The datafile you submit must be in the format as given in the following example:

                    3    0.10
                      29.6  60.0 'PB' 0.0789 0.0200
                      29.6  90.0 'PB' 0.0824 0.0066
                      29.6 120.0 'PB' 0.0521 0.0100
                    5    0.06
                      30.0  60.4 'AYY' 0.251 0.012
                      30.0  75.5 'AYY' 0.222 0.017
                      30.0  90.5 'AYY' 0.262 0.016
                      30.0 105.5 'AYY' 0.247 0.015
                      30.0 120.5 'AYY' 0.164 0.010

The first line gives in a 2 character string (capitals!) the reaction: PP or NP

Then follow the data in groups; a group of data consist of data that all have the same normalization uncertainty in common.

The first line of a group of data consists of 2 numbers: first the number of data that follow and second the normalization uncertainty. (In the example: the first group consists of 3 data and have a 10 percent normalization uncertainty). Use 0.0 for the normalization uncertainty if your data are absolutely normalized,choose 2000.0 if your data are not normalized.

Next follow the data in the group; each line has 5 entries:

  1. The lab-energy Tlab in MeV
  2. The CM scattering angle in degrees; if your data are total cross-sections use 0.0
  3. The observable enclosed in a pair of apostrophes, in capitals
  4. The experimental value
  5. The experimental uncertainty

The maximum number of data that can be handled at the same time is approximately 2000, but the more you submit - the longer it will take to perform the calculations, especially for pp-scattering (and to upload your file and to download the results!)

If you have any requests, comments or questions about this program please contact us! 27 May 2022