class HKickTrack: public TObject

_HADES_CLASS_DESCRIPTION

HKickTrack

  This is the output of the HKickTrackF class which matches a segment
in MDC (class HMdcSeg) with a hit in Meta (HTofHit or HShowerHitTof)
and assigns the corresponding momentum.

  Documentation for the non-trivial data members follows:

  pTof .-
    For each track the momentum is determined using to approaches:
       a) The track's deflection in the field. The resultin momentun is p
       b) With p and the track's time of flight the mass is calculated.
          On the basis of the mass and charge the particle is identified,
          once the particle is 'known' it's mass is forced to be on the
          correct value and the momentum is recalculated under this
          condition. The resulting momentum is stored in pTof.

  pid.-
    Particle's PID. See HKickTrackF / HKickMassFit for more information.

  quality.-
    When for a segment in MDC there is only one hit in Meta within the cuts
    a track is formed with quality=1. When several hits in Meta are within
    the cuts several tracks are built with quality=0, thus deferring the
    resolution of such events for a later stage in the analysis.

  r,z,theta,phi.-
    Same meaning as in HMdcSeg

  mass.-
    Despite of the name. This variable actually contains the squared mass
    determined from p and beta.

  system.-
    0  - the track was formed with an MDC segment and a Shower hit
    >0 - the track was formed with an MDC segment and a TOF hit.

  showerSum10, showerSum20
    For the case system==0. showerSum10=showerhit.sum(1)/showerhit.sum(0)
    showerSum20 = showerhit.sum(2)/showerhit.sum(0). See HShowerHit for
    information on what sum(2),sum(1) and sum(0) are.

  segmentId.-
    Id of the MDC segment used to build the track. The segment's HLocation
    is derived from segmentId as follows.

       segLoc.set(3,sector,0,segmentId)

  outerHitId.-
    Id of the segment in Meta used to build the track. There are two
    possibilities:

    system==0   <=> Shower was used

      HShowerHit *hit = (HShowerHit *)catShowerHits->getObject(outerHitId)

    system>0    <=> TOF was used

      outerHitId = tof.sector*1000 + tof.module*100 + tof.cell

  pull.-
    (x_meta - x_mdc) / sigma(x_meta - x_mdc). Where
    Where:
      x_meta -> x coordinate of the hit in Meta used to build the track
      x_mdc -> x coordinate of the MDC segment in the Meta detector.
               The MDC segment used to build the track is propagated
               trough the magnetic field and it's intersection with the
               Meta detector is computed. x_mdc is the x coordinate of
               such intersection point.