# Data sets

There are two types of data sets that ship together with Gepard. One are original sets published by experimental collaborations which made the measurements. Another are derived sets where original sets are transformed in some way (e. g. by discrete Fourier transform). Every data set and point has the attribute reference which should explain if it is original or derived.

Here we list most of the available data sets, with some comments on how we chose to use them in our fits.

Todo

This is a stub. Most of datasets have yet to be added below.

## ZEUS

### Chekanov:2003ya hep-ex/0305028

```
>>> import gepard as g
>>> g.list_data(45)
[ 45] ZEUS 6 X 0305028 Table 1
```

We take data from Table 1 with DVCS cross section in dependence on Q2. Tables 2 and 3 are same data but binned for W dependence. Using Q2 dependence gives us handle on evolution.

### Chekanov:2008vy arXiv:0812.2517

```
>>> g.list_data([46, 47, 48, 49])
[ 46] ZEUS 4 X 0812.2517 Table 4
[ 47] ZEUS 6 X 0812.2517 Table 1
[ 48] ZEUS 6 X 0812.2517 Table 2
[ 49] ZEUS 8 X 0812.2517 Table 3
```

We take data from Table 1 (Q2 dependence of cross section, one might cut low-Q2 points) while Tables 2 (and 3) are same data binned in W (W and Q2). We also take data from Table 4, which is differential cross section in t, extracted from the subset of the above data, so strictly it is not statistically independent.