Analysis

Event display Data sets Running the display Commands For afs-challenged Interactive reconstruction

Analysis software is derived from the old MINOS reconstruction program and its interactive version, MAW developed by Robert Hatcher.

Event display program

Event display is based on a MAW package. It presents raw data as recoded on a set of collection (X view) vertical wires and two sets of induction wires oriented at + - 30 degrees stereo angle (U and V views).

Every view has two windows: one showing the entire event and a zoom window. The size of the zoom window can be adjusted as necessary. In the X view the zoom window can be moved around.

The display shows the position of 'hits' as recorded on wires. Wires are perpendicular to the screen, the x-axis is the wire number, expressed in the position of the wire, in cm. The y-axis is a drift time, again converted to cm. All hits within 3 microseconds (or 5 mm drift distance) are coalesced into one. Pulse height is represented by colors: the color scale is chosen such that a single particle perpendicular the wire and parallel to the wire plane is green, whereas pulse height corresponding to two or more particles is red. Note: single/double particle pulse height depends on the angle of the track!

Data sets

Data files are resident in the afs space. Files of neutral current interactions, n_m CC interactions, n_e interactions with the oscillation signal as well as with the intrinsic n_ebeam component corresponding to NuMI off-axis spectrum are available. More data sets can be generated upon request.

Running the display

This software is maintained un UNIX-like platforms. It resides on FNALU cluster and it is available through the afs file system. The primary version is running under linux. Other flavors can be created upon request.

The easiest way to run the program is to run it on a linux computer with an afs client installed. The next easiest method is to copy all binary versions and all other relevant files to a local machine, ask for instructions if you want to work this way.

If you do not have an afs client you need to copy over the binaries and all the kumac/fortran files. Follow the instructions and continue reading here.

To run the display program on a linux machine with afs client :

> cd /afs/fnal/files/code/off-axis/off-axis_01/ana_lar

> source setup.csh

> ./lar_maw

Workstation type (?=HELP) <CR>=1 : hit return

RECO>

This is a prompt indicating that the program hast successfully started. The HIGZ graphics window should pop out too.

Commands and macros

These commands and macros are kumac files and fortran functions designed to simplify some common tasks If you have questions or comments about their functioning or if you have a suggestion of an additional functionality which would be helpful - send feedback .

to open new data file and start scanning:

exec to_scan S='X_1' This command applies specifically to the off-axis neutrino files. 'X' refers to the data category and should be replaced by a value 6-11 as defined in the data files directory. '1' refers to the data file of a given category. Files contain typically 1000 events.

to read in and display next event:

proc 1;xyuv

to print (in the text window) a list of particles produced at the interaction vertex:

call particles

to size and move around (in X view) the zoom window

exec zoom t=t_size x=x_offset zz=z_offset z=z_length, where

t_size - transverse size of the zoom window (cm)

x_offset - x displacement of the zoom window in X view, in cm

z_offset - z -displacement of the zoom window in X view, in cm

z_length - size of the zoom window along the beam direction

Only parameters different from the standard values need to be present

to reset the zoom window to the standard position

exec zoom

overlay vectors indicating the direction of primary particles (X view only)

exec traj T=flag, where flag=1 - turn the display on, flag=0, turn the display off

Colors indicate particle types:

black     - muon

red        - electron

green     - charged pion

blue       - proton

yellow    - neutron

magenta - kaon (charged or neutral)

to save event to a Postcript file (you must be running a program in a directory where you have write access. Consider copying /afs/fnal/files/code/off-axis/off-axis_01/ana_lar to your local computer)

add2meta

For afs-challenged

If for some reason you do not have an access to the afs space you may install a binary version of the display program (linux!!! other can be created upon a request) using a tar file.

Once you copy and un-tar this file you may follow all the instructions listed above. Do not forget 'source setup.csh' ! You will not have the data files, though. You can copy all or some of them from their repository. Beware: these files are very large.

To have a fully functional system you need to edit file 'to_scan.kumac' and update the location of the data files on your system. Ask for help if necessary.

Interactive reconstruction

Interactive reconstruction program allows operator-guided event reconstruction. Its primary goal is to identify and reconstruct tracks originating at the interaction vertex. The reconstruction process consists of three steps:

definition of a primary vertex
identification and reconstruction of tracks
saving the results of the reconstruction

The reconstruction program is a derivative of the scanning program described above and the scanning instructions are fully relevant. The program resides in a directory: /afs/fnal/files/code/off-axis/off-axis_03/my_maw and it is invoked by a command: ./LAIR (Liquid Argon Interactive Reconstruction).

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