Matching ENFLW informations and true information

The code providing this information is available since ALPHA 122.30 (June 1997).

For charged tracks, the matching between ENFLW objects and Monte Carlo true information (and vice-versa) is done by the standard KMTCH function (7.7 on p. ).

For ECAL objects, it is done using the PEMH, PECO and PCOB banks. For HCAL objects, it is done using the PHMH, PHCO and PCOB banks for datasets generated with JULIA version 285.1 and after (March 1996 and after); for previous datasets a tight angular matching (100 mrad) is used as a substitute when PHMH is not available. For ECAL hadronic residuals (KEFOTY = 5) and SICAL clusters (KEFOTY = 8) the matching is not fully efficient, since the FKIN/PECO information is not stored for SICAL clusters.

The matching information is provided through the following functions:

KNTRU (ITK)

Number of matches of ALPHA ``track" ITK

The matching is ENFLW $\rightarrow$ Monte Carlo if ITK is between KFEFT and KLEFT

The matching is Monte Carlo $\rightarrow$ ENFLW if ITK is between KFMCT and KLMCT

As for charged tracks, any ENFLW object may have more than one match, therefore additional information is provided through the following functions:

KTRU (ITK,I)

Ith match to ALPHA ``track" ITK (I=1,.. KNTRU(ITK))

QSTRU(ITK,I)

Matching quantity for the Ith match to ALPHA ``track" ITK

• if QSTRU < - 1.0: (-QSTRU) is the number of shared VDET + ITC + TPC hits
• if -1.0 < QSTRU < 0. (-QSTRU) is the matching angle (in radians) for HCAL/SICAL
• if QSTRU > 0. QSTRU is the shared energy (from PEMH or PHMH banks)