Vertex attributes

The following attributes are all vertices. The argument (IVX) always refers to vertex IVX.

Warning : JULIA or QFNDIP Main vertex ?

For the Main vertex (IVX = KFREV and KVTYPE(IVX) = 1, see below) the quantities described below may have been obtained either from the JULIA vertexing or from the QFNDIP package if you asked for it through the data card QFND ( sec 4.17). See the entry QVCHIF below to know which package was used to give the Main vertex positions .

QVX (IVX)

x position

QVY (IVX)

y position

QVZ (IVX)

z position

KVN (IVX)

JULIA/GALEPH vertex number

KVTYPE(IVX)

vertex type

• = 1 for the Main vertex;

• = 0 for standard reconstructed V0s from YV0V

  (IVX = KFREV,KLREV)

  or for MC ``truth'' vertices (IVX = KFMCV,KLMCV)

• = 2 for a secondary vertex fitted by any of the KVFITx routines, see sec 9.3 on p. .

• = 3 for a ``Long V0'' vertex from the new tracking

• = 4 for a Nuclear Interaction vertex from the new tracking

• = 5 for a Kink vertex from the new tracking

Vertex types 3,4,5 are defined only for datasets produced with JULIA version 302 and after.

QVCHIF(IVX)

Chisquare of the vertex fit.

Special meaning for the Main vertex:

Always 0 if the Main vertex was found by JULIA.

If the Main vertex was found by QFNDIP, this chisquare is positive.

If QFNDIP was called and was unable to find a Main vertex, this Chisquare is set to a huge negative value.

QVEM (IVX,N,M)

element (N,M) of the covariance matrix N,M = 1,2,3 in the following order: QVX,QVY,QVZ.

QVEM (IVX,1,1) is set to -1. if the error matrix is not available.

See Section 7.8 for pointers between ALPHA tracks and vertices.