If Method=1, then one can obtain higher purities by using the BNEG card. This allows QIPBTAG and QBMTAG to use information from both +ve and -ve impact parameter tracks. (See ALNEWS 1389 in OFFLINE folder). If one omits this card, however, then in the same way as one can measure the uds efficiency of QIPBTAG using the -ve hemisphere tag NPROBHEMI, it is possible to create a -ve tag from QBMTAG for the same purpose. This can be done by calling it with argument NPROBTRK instead of PROBTRK.
Please send all remarks concerning this package to : Ian.Tomalin@cern.ch