Getting started with the 1997 Testbeam analysis

Rudi Ganz Oct. 1997 (first draft)

The testbeam analysis right now has the following structure:

First create Analysis directory eg. Analysis and subdirectories.

Download and unzip files. On UNIX use unzip -a command to for text archives.

add files according to that structure (also I assume, that you’ve installed root on your machine)

Then go in the /run directory; edit the ped.c and CheckPed.c files according to your local directory structure. (especially the file PhTestBeam.dll should be in the run directory)

run dos.bat and in the dos window run root.

The analysis then goes as follows:

Step I Produce Pedestal files

Produce Pedestal files from the pedestal events only:

DATA ---> .x ped.c ---> Pedestal files

The files will sit in the pedestal directory and will be called:

Tele_00xxx.ped

Phob_00xxx.ped

WA98_00xxx.ped

Where xxx is according to the run number

Step II Check the pedestal files

Produce histograms before and after pedestal subtraction

DATA+Ped.Files ---> .x CheckPed.c ---> CheckPed.root

The CheckPed_00xxx.root files contain root histograms which you can examine

within a root session

Step III Compession of the data

Run the analysis to write all important information into a root tree

Information in the tree:

- The PHOBOS detector

We will write all 48 channel of the PHOBOS detector but subtract the

pedestal generated by ped.c. We will not subtract common noise (can be

done later since we keep all channels) In the output we will not suppress

any channel of this detector

- The WA98 detector

We will subtracted pedestals and correct for common noise and keep only

those channel which are above a certain threshold

- The telescope

We wil subtract the pedestals and make a common noise correction. Then we

cluster all hits on each telescope detector and write a center channel values

for each telescope detector to the tree

• Others

On a fraction of the run we had the hodoscope added in the data stream

We will just pass that information to the tree

Step IV Physics analysis

This analysis depends on the things you are interested. I will prepare a template file which read the root tree and performs some general step in the analysis. Then you can add your specific code to it.

We will coordinate this part of the analysis once we have the treee for all the files