# Unfold_070612

```Unfolding Study
07/06/12
1
RooUnfold
Using the RooUnfold 1.1.1
 In this study we make response matrix from MADGRAPH MC and use it to unfold the
CMS Data
Plots we are interested are rapidity of Z and jet in Z+1jet events i.e.
 Yz, Yjet, different of Yz and Yjet, and sum of Yz and Yjet
 The unfolding methods are
 Bayes with number of iteration = 4
 Svd with ktern =15 (total number of bins) i.e. just inverts matrix
 Bin by Bin
 Also we checking the error by running the “toy” experiments, where the statistics of the
response matrix are varied
 Closure test using pythia dataset?????????

2
Response Matrix
3
|Y of Z|
Bayes
Svd
Bin by Bin
The corrections for all 3 methods are small.
 The corrections are almost the same for all 3 methods.

4
|Y of jet|
Bayes
Svd
Bin by Bin
The corrections are bigger than that of Z but still considerably small.
 The corrections are almost the same for all 3 methods.

5
0.5|Yz+Yjet|
Bayes

Svd
Bin by Bin
Y sum again shows the small and consistent corrections for all methods.
6
0.5|Yz-Yjet|
Bayes
Svd
Bin by Bin
Y diff shows the small corrections but not the last two bins.
 There big corrections in last two bin might be from low statistic (big errors).

7
Error Test

“Toy” experiments is used to vary the statistic of response matrix with below code:
unfold.SetNToys(1000);
TVectorD errVector = unfold.ErecoV(3);
unfold.PrintTable (cout, hGen);
ErrVector.Print("all");

The result from the code is random number in the table below
Vector (15) all is as follows
|
1 |
-----------------0 |163.426
1 |151.223
2 |137.28
3 |117.141
4 |95.0418
5 |72.9619
6 |53.6503
7 |37.5361
8 |24.1118
9 |13.5451
10 |5.27294
11 |0
12 |0
13 |0
14 |0
8