Production:CDC_VTX;Track_Parameter

 		Element# 		: 		 Track number.
		TBPUT by 		:		 Smearing routine.(SMRCVT)
		Contents 		: 		 CDC-VTX combined track information.
		Format 		: 		 R*4, R*8, I*2,  & I*4 mixed fixed length (55)

 				 RBUF(1-3)=Í<>px, py, pz.
				 (4)=Í<>E assuming massless particle.
				 (5-7)=Í<>x, y, z of closest approach to the beam axis.
				 IBUF(9)=ápparent charge ( +/-1 )
				 RBUF(11-15)=d$\rho_0$(cm), $\phi_0$(radian), $\kappa$(GeV-1), dZ(cm), and  $\tan\lambda$ of track parameter.
				 (16-18)=Pivot of track parameter, X0, Y0, and Z0.
				 DBUF(10-24)=érror matrix (lower triangle only)
				 RBUF(49)=not used ( reserved for confidence level )
				 (50)=not used ( reserved for $\chi^2$ )
				 HBUF(1,51)=Number of degrees of freedom.
				 (2,51)=not used ( reserved for duplicate flag )
				 (1,52)=Number of track parameters ( 5 for helices )
				 IBUF(53)=Track type
				 (54)=pointer to "Production:CDC;Track_Parameter"
				 (55)=pointer to "Production:VTX;Space_Point" 

The first 52 words have the same meanings as those of "Production:CDC;Track_Parameter". The track type is the number of linked VTX hits, if positive. Otherwise, it signals the failure of combined fitting.

 

track type = -1 to 0 : identical to the corresponding CDC track

= 2 : CDC-VTX combined track

Notice that there is a one-to-one correspondence between CDC tracks and CDC-VTX combined tracks: CDC track #i corresponds to CDC-VTX track #i. At present, no actual fitting is performed, instead, the track is assumed to pass exactly through the VTX hit positions and to have the momentum given by CDC.