A BRIEF EXPLANATION OF THE IMPORTANT MODES OF OPERATION OF THE E789 PAM 9.7 ANALYSIS AND CRADLES - Updated for 9.7 - MJL 4/22/92 FIRST AND SECOND PASS First pass includes fast-silicon analysis, various fast cuts, the drift chamber tracker, swimming through SM12 with aperture cuts, full silicon tracking with masking from the downstream tracks, and physics reconstruction. For first pass the following patchy switches should be set: JACTRACK and ETM on. READDST and RETRACK off. JACTRACK activates the drift-chamber (downstream tracker) and ETM activates the code to obtain the run and spill number from the etm data block and then go to the appropriate rasputin file to get the run and spill data. Second pass (i.e. reading a dst) is a subset and refinement of the above. Normally one doesn't retrack the drift chambers but instead uses the tracks stored in the dst and then does the rest of what is done for the first pass. For second pass the switches needed are: JACTRACK and ETM off; READDST on. If you want to retrack in the second pass: READDST, RETRACK, and JACTRACK on; ETM off. READDST activates code to read and unpack the software data blocks in the dst which were placed there by a previous analysis (e.g. the first pass). RETRACK will cause the downstream tracking to be partially redone (caution - retrack may not work if the downstream alignment constant, etc are changed a lot - see subroutine GETHITS). note: PASS1 and PASS2 are always kept on now as they refer to the old analysis where the downstream tracking and the swim throught sm12 were done in different programs. FAST-SILICON ANALYSIS The fast-silicon tracker which can run with no input from the downstream spectrometer or can be masked by either the processor tracks or the down- stream tracks. It can be used to make impact parameter cuts or just to determine alignment constants without any cuts. To run fast-silicon tracker: FASTSI on. TGTPAIR on to look for target pairs. DNPAIR on to look for downstream pairs. FASTER on for fast but inefficient mode (e.g. to determine alignment only) FASTMASK, FASTMSK1, and FASTMSK2 off for no masking. FASTMASK and FASTMSK1 on for processor masking. FASTMASK and FASTMSK2 on for drift chamber track masking. switch(55)=-1 for not cuts = 0 for cuts (requires pair and impact parameter cut) RUNSHFT The fast-silicon tracker can be used to determine the alignment of the target/beam and record the result in the dst for later use. RUNSHFT involves 3 different modes of running. 1) BFIT mode which is used to determine initial alignment for a tape by doing a very fast pre-analysis of the first few thousand events on the tape. The values determined are then written into a file (environment variable SISHFT) where the regular program will pick them up from when it starts. This gives the regular program the correct alignment for the first spill. BFIT on; RUNSHFT and RUNSHFT2 off. 2) RUNSHFT mode which is used for normal first pass analysis. It gets the intial alignment from above, then determines new values at the end of each spill and used them for the next spill. These values are recorded with with each event in the dst track bank ("jtrace+5 and +6"). RUNSHFT on; BFIT and RUNSHFT2 off. 3) RUNSHFT2 mode which is for second pass analysis. It uses the alignment values which were put in the dst by the above mode. At present there is a conflict between RETRACK and RUNSHFT2 so that this mode doesn't work for retracking. I think this can be easily fixed. RUNSHFT2 on; BFIT and RUNSHFT off. FULL SILICON TRACKING The full silicon tracker (SITRAX) uses the downstream tracks iterated to the target location to mask the silicon hits. It then does a thorough search for tracks including a chisq fit to the y and uv plane hits. These tracks (combined silicon and drift chamber tracks) are then passed to DIMUSE where vertices are constucted and cuts including vertex cuts are applied. At present the vertex cuts include only the requirement that there be one good pair that points to the vicinity of the target and that the z of the vertex lie within certain bounds. Tighter cuts are applied by PAW when looking at the ntuple which includes results from the vertexing. To use the full silicon tracker: NOSIL and NOUV off; and NOBCUT on. To turn it off: NOSIL on. Old capabilities to do a "full-fit" chisq fit including the silicon and the drift chambers and to do a "pairfit" which fits two such full tracks and forces them to a common vertex are presently not operational. Also three switches control what silicon track or vertex cuts are made in dimuse. FAILSI fail a jactrack if no silicon tracks are found NOBCUT2 make no loose Z vertex cut on all pairs NOBCUT make no tight vertex and impact parameter cuts (e.g. the production has NOBCUT2, NOBCUT on and FAILSI off) PIX There are two separate picture routines, PIX and SIPIX. I have hacked the multi glib to run on unix machines and these now work on unix machines. To get the whole apparatus pictures: PIX, PICTURES, and VAXPIX on, and switch(53)=-1. switch(53)=0 turns them off. To get the silicon pictures: SIPIX on, and switch(61)=-1. switch(61)=0 turns them off. PROCESSOR The processor data can be unpacked, histogramed, and used for masking. Don't turn this stuff on if the data has no processor data. PROCESSR, and NEWPDAT on for 1991 processor data. PROCMSK on for processor masking of the drift chamber tracking. FASTMASK and FASTMSK1 for masking of fast-silicon with the processor (as noted above in the fast-silicon section) MATRIX The matrix files are obtained from the directory pointed to by the environment variable LUNMAT. They can be used for checking the integrity of the matrix, and for matrix masking of the downstream tracker. MATBUG, MATERR, and HOTCELL on for matrix diagnostics. When MATBUG is on then matrix masking of the downstream tracker is also on. PID (PARTICLE ID) NOPID no pid cuts are made but the PID's of each track are determined and inclusively recorded in the EGS data word for each event. HADTRIG disables muon (station 4) cuts on tracks in first pass. DIHAD makes dihadron cuts in DIMUSE. DIMUON makes dimuon cuts in DIMUSE. GPID turns on new code that attempts to do loose inclusive PID cuts in DIMUSE for all triggers in an inclusive way. PID can be derived eiter from mubits or from the calorimeter routines. Since the latter are still under development only the mubits PID is used in "production" running at present. CALORIMETER CALCUT turns on gross calorimeter threshold and em-fraction cuts at the beggining of the first pass. (i.e. gross means based on total sums without association with tracks) CALOR turns on calorimeter cluster analysis. COMPUTER TYPES RISC on when on a unix machine (as opposed to a VAX). SGI on for Silicon Graphics HP on for Hewlett Packard IBM on for IBM. FARM, FARM1, FARM2, FARM3 used for farm version. MISCELLANEOS SWITCHES HODANA, HODOEFF, and HODTIM turn on hodoscope diagnostics. PTUBEFF turns on prop-tube efficiency analysis based on projections of drift chamber tracks into station 4. DCTIME, CKSUM, TIMANA, TZERO, TVSD; drift chamber tdc tuneup. RSPMAP for Preston field maps. RSP18 for 18" (fast) Preston field map (RSPMAP must be on too). SWAP swap byte on input data for VAX (must be done when reading and 8mm data tape on the VAX). MCARLO for monte carlo comparisons APUPK to unpack the array processor block which contains monte carlo thrown quatities HBMC for monte carlo comparison histograms MAKEDST to make a dst (always on) TRACEDST to make a trace dst (always on) DSTSIL to put silicon track block in the dst (new) NOTE Most of the switches not mentioned above are either obsolete, must always be on, or are rarely used. Typically switches which have not been used for a long time may not actually produce the expected results without some debugging.