- Common Block Description
- Vertex Lists
- Track lists
- Subtype 1 : Track Identification Block
- Subtype 2 : Unused
- Subtype 3 : One-Track Fit
- Subtype 4 : Time-Of-Flight Counter Items
- Subtype 5 : Shower Counter Track
- Subtype 6 : Muon Chamber Items
- Subtype 7 : DE/dx Information
- Subtype 8 : Vertex Constrained Track Fit
- Subtype 9 : Drift Chamber (DC) Pointers
- Subtype 10 : Shower Counter (SC) Pointers
- Subtype 11 : Projected/Decay Coords Of DC Tracks
- Subtype 12 : Reconstructed (virtual) Track

RAWDAT - Which holds the raw event data (ADC values etc.) Certain track subtypes point back to the relevant rawdata portion of this block. EVLST - Which contains event description information and pointers to the track and vertex information in TRKLST. In particular the TRKSUB and VRTSUB arrays are used to index the the track and vertex entries . The counters TOTTKS and NVTX give the number of track and vertex entries pointed to by TRKSUB and VRTSUB respectively. TRKLST - Which contains the track and vertex information blocks (subtypes) in one large array. For the exact contents of these commons please refer to the source files with filetypes .INC in BES$LIBPAMS:[BESCDE]. Only those parts relevant to this document are included . The quantities of interest here are; TOTTKS : total number of entries in the TRKSUB array. This is the largest value of the 2-nd index of the TRKSUB array for the event. NVTX : number of vertices (15 max) in the event This is the largest value of the 2-nd index of the VRTSUB array for the event. VRTSUB : pointers to ITRK where vertex lists are located (a zero value indicates non-existent subtype) TRKSUB : pointers to ITRK where track lists are located.(A zero valued pointer indicates non-existent subtype) The value in TRKSUB points to the TOP of the record of interest so that ITRK(TRKSUB(n,trk)+1) is the first word of subtype=n for track=trk. (Also true for VRTSUB ) NXTSUB : Points to the last word filled in the TRK buffer. (i.e. next free location is TRK(NXTSUB+1) ) TRK : large multi-purpose array which stores the vertex and track lists, amoung other things. The first 26 words of ITRK store the sizes of arrays and lists, in the following order ; Initial value of NXTSUB on each new event, Number of words in /EVLST/ preceding vrtsub, Dimension of VRTSUB (2 items), Lengths of vertex subtype lists (8 items), Dimension of TRKSUB (2 items), Lengths of track subtype lists (12 items). Notes: The subtype 1 entry of a vertex or track entry must be filled in order for that entity to be logged out. I.e. unattached subtypes will be weeded out by EVLOG during data logging. The order of the VRTSUB and TRKSUB indices is subtype first, track or vertex number second.[top]

Item =TRK(VRTSUB(N,V) + J) .

J NAME CONTENTS - ---- -------- 1 NWDS number of words in this record 2 NPRNG number of charged prongs in this vertex 3 NEU number of neutral prongs in this vertex (total tracks in this vertex is N = NPRNG+NEU) 4 IVTYPE Normally 1. Set to 2 if TOF disagrees with the ID made by VEEFND for sec tracks. 5 IVID ID of most probable decay -1 = cant tell 0 = not made 1 = K zero, 2 = anti-lamda, 3 = lamda, 4 = gamma (conv at pipe) 5 = pi zero, 6 = eta 100 = D vertex (charged or neutral) (if ambiguous, tens digit gives other choice) 6 IBACK index of backward (parent) vertex 7 INTRK track number of incoming track 8 NFORE number of forward vertex linkages 9-13 IFORE indices of foreward linking vertices 13+1 ITK track numbers for this vertex (outward tks.) . . " . . " 13+NPRNG . " . . " 13+NPRNG+NEU "[top]

J NAME CONTENTS - ---- -------- 1 NWDS number of words in this record 2 IVFIT method : 0=simple averages, large fid vol 1=fit for min dist, large fid vol 2=simple averages, small fid vol 3=fit for min dist, small fid vol 3 IQTOT total charge of the prongs 4 RVXY Perp distance from origin (0,0) to vertex . 5 XV x (m) of vertex 6 YV y (m) of vertex 7 ZV z (m) of vertex 8 XER error in x (m) 9 YER error in y (m) 10 ZER error in z (m) 11 CH2TOT total chi sq for vertex fit (-1.0 if failed) 12 DFTOT degrees of freedom 13 NTRKS The number of tracks used in crude fit. 13+1 TRKNUM List of the charged tracks used in this +2 " vertex fit. . " . . . 13+NTRKS

Note: This subtype is filled for Vee's as well as the primary vertex.

J NAME CONTENTS - ---- -------- 1 NWDS Number of words in record 2 IVCFIT Fit type (0 = simple ; 1 = good ) 3 IVCQT Total charge of the prongs 4 RVXY Perpendicular distance (x-y) from vertex to nominal beam location (XYZIR(1-2) in /RUNPRM/ ) 5 VCXV X (m) of vertex 6 VCYV Y (m) of vertex 7 VCZV Z (m) of vertex 8 VCXER Error in X (m) 9 VCYER Error in Y (m) 10 VCZER Error in Z (m) 11 VCCH2T Total ChiSq for vertex fit (set to -1. if fit failed) 12 VCDFT Degrees of freedom (REAL) 13 VCCH2V ChiSq contribution from X,Y,Z 13+1 VCH2NP ChiSq contributions from . . individual tracks . . " . . " 13+NPRNG+NEU "[top]

J NAME CONTENTS - ---- -------- 1 NWDS Number of words in this record 2 ACOLL Acollinearity angle (radians) 3 ACOPL Acoplanarity angle (radians) (ACOLL,ACOPL = 0. ,if back to back) 4 LCOLL True if acollinear and xyz's match 5 LCOPL True if acoplaner and xyz's match[top]

J NAME CONTENTS - ---- -------- 1 NWDS Number of words this record 2 MFSEC Method of finding secondary vertex 1=veefnd, 2=pizero, 3=kink 3 SMASSO Mass calculated from tracks at origin 4 SMASSV Mass calculated at sec vertex point 5 SCOS12 Cos of angle between vee tracks 6 SCOSOP Cos of angle between neutral decayer and direction of secondary momentum vector 7 SPTOT Total momentum of secondary tracks 8 SPTOTX " x-mentum " " " 9 SPTOTY " y " " " " 10 SPTOTZ " z " " " " 11 SZDIFF Z difference at XY point of secondary. 12 SENRGY Total energy of secondaries 13 SCH2 Chi square of fit (=-1.0 if fit failed) 14 SDF Degrees of freedom[top]

J NAME CONTENTS - ---- -------- 1 NWDS Number of words in this record 2 NDTRKS Number of decay products in the D tag 3 ITAG Code for the D decay mode ITAG decay mode ---- ----- ---- 1 K- pi+ 2 K- pi+ pi+ 3 K- pi+ pi+ pi- 4 K0 pi+ 5 K0 pi+ pi- 6 K0 pi+ pi+ pi- 7 K- pi+ pi0 8 K- pi+ pi+ pi0 9 K0 pi0 10 K0 pi+ pi0 11 K+ K- 12 K+ K- pi+ 13 K+ K- pi+ pi- 14 pi+ pi- 15 pi+ pi+ pi- 16 K+ K0 17 K+ K0 pi- 18 pi+ pi0 4 ICHRGD Charge of the D 5 DMASS D final state invariant mass 6 BCMASS Beam-constrained mass of the D 7 PXD Px of the D 8 PYD Py of the D 9 PZD Pz of the D 10 PD Total momentum of the D 11 ED Total energy of the D 12+13 ITKMAP A double word bit map indicating track numbers used in the TAG. Track # 1 corresponds to the LSB (20) of the first word. 13+1 IDTRK Packed word for each of the decay . products of the D. Format is: . . BYTE4 BYTE3 BYTE2 BYTE1 . +-----------------------------------+ . | | | | | . | DKTRK1 | DKTRK2 | TRK# | TRKID | . | | | | | . +-----------------------------------+ . . where... . . TRKID = particle type for the decay . product . . 1 = chg pi . 2 = chg K . 4 = pi0 . 8 = K0 . . TRK# = BES track number assigned . to this particle. (virtual . track in the case of pi0 or K0) . . DKTRK1(2) = BES track numbers of the . the gammas from a pi0 or . the pions from a K0. 13+NDTRKS (only filled when TRKID=4,8)[top]

Item = TRK(TRKSUB(N,T) + J)

J Name Contents - ---- -------- 1 NWDS number of words in this record 2 ID track identifier: 0 = no identification made 1 = gamma 2 = electron 3 = muon 4 = pi 5 = K 6 = P 7 = LAMDA, 8 = ANTI-LAMDA 10 = ETA &le 0 = external track (e.g. backscatter) 3 IDUSED Bit mask indicating data used in particle identification. The bit positions are encoded as follows ; mask Data type ---- ---- ---- x'01' TOF x'02' dE/dx x'04' Muon tubes x'08' Shower counter 4 ICHRG charge 0, +1, -1 (9 if cant tell sign) 5 ITKTYP A bit mask indicating the track type. the systems are encoded as follows ; mask System ---- ------ x'01' Drift Chamber x'02' Barrel shower counter x'04' DC SC data fitted simulaneously - x'08' Virtual (reconstructed) track x'10' Hardware track info x'20' TOF info x'40' Muon tubes x'80' End cap shower counter 6 MISS Bit mask indicating information lacking due to geometry. The systems are encoded as follows; mask System ---- ------ x'01' TOF x'02' Drift Chamber x'04' Shower chamber x'08' Muon tubes (It WOULD be too much to expect they'd be the same as any of the above....) 7 IVFROM vertex # from which this track originates 8 IVDCAY vertex number that this track decays to (0 if none)[top]

J Type Name CONTENTS - ---- ---- -------- 1 I NWDS number of words this record 2 I ICHRGE charge of track, +1, -1 3 R PXYM at min. dist. of approach to beam origin 4 R PXM " 5 R PYM " (note that PZ/P gives cos(THETA), 6 R PZM " PXY/P gives sin(THETA), 7 R P " PX/PXY gives cos(PHI), 8 R THETA " PY/PXY gives sin(PHI) 9 R PHIM " so use ratios rather than sin/cos 10 R XM " to save cpu time ) 11 R YM " 12 R ZM " 13 R RM " 14 I MFIT Fit method: 0 = circle fit 2 = ARCS fit 15 I NDCH Number of drift chamber hits in the fit 16 I IHIT Not used 17 R CH2 Chi square from single track fit 18 I DF Degrees of freedom 19 R RMS Rms error of fit (ideally 1.0) 19+1 R ERR Error matrix for good fit, triangular form . . in coordinate : PHI,K=1/PXY,S=TAN(LAMBDA), . . KSI,ETA(does not contain scattering error) . . from pipe) . . . 19+15 R . . 35 R AD1 Distance from origin to first reconstructed layer 36 R AD2 Total length of scattered track in measurement region 37 I IWPLAN Bit map (bits 0-32) of DC layers used AFTER fit 38 I IWPLA1 Bit map (bits 33-40) of DC layers used AFTER fit 39 I IVCHIT Bit map (bits 0-39) of DC layers used in fit 40 I : 40+1 I IHIT(1) Predicted cell hit in Radial Layer 1 40+2 I IHIT(2) Predicetd cell hit in Radial Layer 2 . . . . (one word for each of 40 radial wires) . . 40+40 I IHIT(40) Predicted cell hit in last radial wire (=80)[top]

J NAME CONTENTS - ---- -------- 1 NWDS number of words in this record 2:18 Barrel TOF Items 2 AIT azmuthal counter number from projected track fit ( 1.0LE AIT LE 49.0 ) 3 IT counter number (1-48, 0 if no hit) 4 TOF time of flight (nsec) 5 BETA beta of track 6 ZTDC z (m) from TDC information 7 TOFPH corrected pulse height 8 TQUAL TOF quality (1.0=good trk; .LE.2.0=usable) 0.0 if ZT-ZTDC didnt match 2.0 if double hit in counter 3.0 if no hit in counter 4.0 all wts are zero;otherwise TQUAL=1.0 5.0 all wts are zero;otherw.TQUAL=0,2 6.0 if neutral track with good hit 7.0 if more than 2 hits per counter 8.0 missed one tdc (early cosmic) 9.0 if double hit in counter with bad match with ZTDC (partner of track with TQUAL=2.0) means effectively a lower limit on TOF value 16.0 if neutral track with hit at one end 9 WTPI weight for PI 10 WTK " " K 11 WTP " " P 12 WTEPI " " e for e-pi hypothesis 13 AMASS2 square of mass (gev)2 from TOF and P 14 PATH flight path length (m) 15 TOFERR estimate of error on TOF (nsec) 16 LINK Link to track hitting same counter. These links form a closed loop. 17 LINADJ,1 Link to track on adjacent counter (above). 18 LINADJ,1 Link to track on adjacent counter (below). 19:35 Endcap TOF Items 19 AIT azmuthal counter number from projected track fit 20 IT counter number (49-96, 0 if no hit) 21 TOF time of flight (nsec) 22 BETA beta of track 23 ZTDC z (m) from TDC information 24 TOFPH corrected pulse height 25 TQUAL TOF quality (1.0=good trk; .LE.2.0=usable) 0.0 if ZT-ZTDC didnt match 2.0 if double hit in counter 3.0 if no hit in counter 4.0 all wts are zero;otherwise TQUAL=1.0 5.0 all wts are zero;otherw.TQUAL=0,2 6.0 if neutral track with good hit 7.0 if more than 2 hits per counter 8.0 missed one tdc (early cosmic) 9.0 if double hit in counter with bad match with ZTDC (partner of track with TQUAL=2.0) means effectively a lower limit on TOF value 16.0 if neutral track with hit at one end 26 WTPI weight for PI 27 WTK " " K 28 WTP " " P 29 WTEPI " " e for e-pi hypothesis 30 AMASS2 square of mass (gev)2 from TOF and P 31 PATH flight path length (m) 32 TOFERR estimate of error on TOF (nsec) 33 LINK Link to track hitting same counter. These links form a closed loop. 34 LINADJ,1 Link to track on adjacent counter (above). 35 LINADJ,1 Link to track on adjacent counter (below).[top]

J NAME IorR CONTENTS - ---- ---- -------- 1 F SCNWDS I number of words this record 2 F SCNHIT I number of shower counter cell hits 3 F SCPHIT I number of shower counter paired hits 4 F SCXSH R shower coords at first layer hit 5 SCDXSH R shower coords error at first layer hit 6 F SCYSH R .. 7 SCDYSH R .. 8 F SCZSH R .. 9 SCDZSH R .. 10 F SCTHT R shower counter theta angle 11 SCDTHT R shower counter theta angle error 12 F SCPHI R shower counter phi angle 13 SCDPHI R shower counter phi angle error 14 F SCENG R total energy observed in SC (GEV) -- No calibration done, same as SCERAW for the current version 15 SCDENG R total energy error in SC (GEV) 16 F SCCHI1 R quality of SC fit, CHI2 TYPE 1 17 F SCCHI2 R quality of SC fit, CHI2 TYPE 2 18 F SCSTAT R cluster status/link 19 F SCFLAG I shower counter fit flag 20 F SCMOD I module number for this track (1 - barrel, 2 - E endcap, 3 - W endcap) 21 F SCCHID R CHI SQ of identification 22 F SCSHID R 1 = photon (SC particle identification) 1 = electron 2 = mu or min. ionizing 3 = hadron or fake photon 4 = e-h ambiguity or photon fake ambiguity -1 = didn't make cuts for photon fake ambiguity 23 SCWTPH R weight for PHOTON 24 SCWTEL R weight for ELECTRON 25 SCWTMU R weight for MU or MIN. IONIZING 26 SCWTHA R weight for HADRON 27 F SCCOSX R -| direction cosines 28 F SCCOSY R |==> from 29 F SCCOSZ R -| track fit 30 F SCERAW R total raw energy (sum of PHs 0.01) 31 F SCNBLK I number of layer blocks to follow 32 F SCNBLK+SCLAYL I first layer number 33 F SCNBLK+SCHITL I number of hit cells in this layer 34 F SCNBLK+SCENGL R energy deposited in this layer (GeV) 35 F SCNBLK+SCPHIL R average PHI/X for this layer 36 F SCNBLK+SCDPHL R PHI/X RMS for this layer 37 F SCNBLK+SCZL R average Z/Y (M) for this layer 38 F SCNBLK+SCDZL R Z/Y RMS for this layer NB: A "" in these last four quantities indicates the different interpetation for barrel vs endcaps . . in similar fashion for next layer block .[top]

J NAME CONTENTS - ---- -------- 1 NWRDS number of words in this block ( = 6 + 14MULEVP ) 2 MUID muon identifier: 0 = not a mu 1 = mu 2 = cant tell 3 MUSTAT Status bits on: 1-3 if hit within SIGVCT s.d. in V and within SIGZCT s.d. in Z 4-6 if hit had ambiguous Z-pairing 7-9 if g.e.2 tubes hit 10-12 if no Z due to overflows 13-15 if no Z due to 2 trks in same mod 16-18 if no Z due to Z calib problems 19-21 if no Z due to no ganged hit 22-24 if no Z info for track 4 MULEVR number of layers "required" for a muon i.e. the number of layers in which a muon would have to scatter by more than 3 s.d. in position or momentum to avoid being detected 5 MULEVE number of layers "expected" for a muon i.e. the number of layers in which a mu is expected but could miss being detected by any amount of scattering MULEVE > or = MULEVR 6 MULEVP number of layers "possible" for a muon i.e. the number of layers a muon could reach by scattering L.E. than 3 s.d. MULEVP > or = MULEVE Oi= 6+(i-1)14 Offset pointer for layer=i Oi + 1 NSECT octant number for layer=i (0-7) Oi + 2 DELSTR number of s. d. from ranging out due to strag Oi + 3 XPROJ projected x in level=i Oi + 4 YPROJ " y " " " Oi + 5 ZPROJ " z " " " Oi + 6 DVNORM normalized residual in v-plane Oi + 7 PPROJ projected momentum Oi + 8 XMUL expected sigma in position Oi + 9 SIGSTR " " " STRAGGLING Oi +10 XHIT x co-ordinate of closest muon hit Oi +11 YHIT y " " " " " Oi +12 ZHIT Z " " " " " Oi +13 DELPOS number of s. d. between projected track and closest hit Oi +14 AGRMST equivalent grams of iron traversed[top]

J type Name Contents - ---- ---- -------- 1 I NWDS number words this record 2 I NDEDX no. of good dE/dx hits (ex. overflows) 3 I NTOT no. of good dE/dx hits (inc. overflows) 4 I TRBL flag indicating any problems in dE/dx analysis: TROUBL meaning 0 no info (NTOT=0) 1 AOK 2 more overflows than truncated points. PHMP represents a minimum value. ID attempts to take this situation into account properly. 5 Reserved for future use 6 Reserved for future use 7 I ID Particle type from dE/dx fit ID meaning Note: "definitness" 0 inconclusive (error or tail) in the ID of a particle 1 definite e is based on roughly a 95% 2 " mu decision (skew cuts). e.g. 3 e/mu a track within 95% prob. 4 definite pi for a pion and outside of 5 e/pi 95% prob. for all other 6 mu/pi particles is called a 7 e/mu/pi definite pion. 8 definite K One may notice ID is 9 e/K simply a 5-bit integer 10 mu/K with a bit turned on 11 e/mu/K for each particle 12 pi/K hypothesis satisfied: 13 e/pi/K 14 mu/pi/K Mask particle 15 e/mu/pi/K ---- -------- x'01' e 16 definite p x'02' mu 17 e/p x'04' pi 18 mu/p x'08' K 19 e/mu/p x'10' p 20 pi/p 21 e/pi/p 22 mu/pi/p 23 e/mu/pi/p 24 K/p 25 e/K/p 26 mu/K/p 27 e/mu/K/p 28 pi/K/p 29 e/pi/K/p 30 mu/pi/K/p 31 inconclusive (big sigma or high momentum) 8 R PHMP most probable pulse height from truncated mean 9 R PHMPER fractional uncertainty (sigma) on measured pulse height 10 reserved for future use 11 " 12 " 13 " 14 " Note:Following items 15:19 are signed values ! 15 R XSE # of sigma from e 16 R XSMU " " " mu 17 R XSPI " " " pi 18 R XSK " " " K 19 R XSP " " " p 19+j I XTAG(J) status of hit in wire layer . J of layer 2 (J=1-12) . . XTAG meaning . 1 good hit . 2 overflow . 3 no mtac hit 4 predict > 1 track in cell . 5 multiple mtac hits . 6 mtac but no dedx . 7 bad wire . 8 corrected ph is &le 0. . 9 outside good time window 19+12 31+1 PH(J) corrected pulse height for signal . from wire layer J. filled when . XTAG(J) &le 3. . . 31+12[top]

J NAME CONTENTS - ---- -------- 1 NWDS number words this record 2 IVCHRG charge of track +1, -1, 0 3 VCPXY PXY at location of vertex 4 VCPX PX " " " " 5 VCPY PY " " " " 6 VCPZ PZ " " " " 7 VCP P " " " " 8 VCTHET THET "(see note in subtype 3 for this) 9 VCPHI PHI " " " " " " " " 10 VCX X " " " " 11 VCY Y " " " " 12 VCZ Z " " " " 13 VCR R in XY plane (not filled for secondary vertices ) 14 MVCFIT Fit method: 0 = circle fit 1 = good one track fit 15 NVCDC Number of dc hits in the fit 16 spare Reserved - added to make this format the same as Subtype 3 above. 17 VCH2 Chi square from single track fit 18 VCDF Degrees of freedom 19 VCRMS RMS error of fit 19+1 VCERR Error matrix (in phi, 1/pxy, s) . ( diagonal element = 999. and . off-diagonal = 0. for fits with 19+6 VFIT .le.1 . ) 26 VDPX Error PX 27 VDPY Error PY 28 VDPZ Error PZ[top]

J NAME CONTENTS - ---- -------- 1 NWDS number words this record (3+NDCH) 2 NDCH number of dc pointers to follow 3 IDCH bits 20-31: residual in 10 micron units 18-19: unused 16-17: wire side assigned . . 1=+, 2=-, 3 don't care . . 0-15: pointer to IRAW . . e.g. for M'th dc hit in track ITK, let IP=IBITS(ITRK(TRKSUB(9,ITK)+2+M),0,16) . . then IRAW(IP) contains tag word/mtac valueT . . NWDS Spare[top]

J NAME CONTENTS - ---- -------- 1 NWDS Number words this record = # of SC hits 2 + 1 2 HITRAW Raw data of the first hit 3 HITFLG Status flag of the first hit 4 HITRAW 5 HITFLG : : Meaning of HITRAW 31 15 0 : bit ________ | PNT2 | PNT1 | |____|____| BARREL : PNT1 = pointer to east end of wire PNT2 = pointer to west end of wire ENDCAP : PNT1 = pointer to top end of wire PNT2 = pointer to bottom end of wire For meanings of HITFLG, refer to HITLST.INC[top]

Following format for PROJECTIONS (IVDCAY=0) --------- ------ --- ----------- ---------- J NAME CONTENTS - ---- -------- 1 NWDS number words this record 2 XBT coords at barrel TOF radius 3 YBT " " " " 4 ZBT " " " " 5 THETBT direction of track at XT,YT,ZT 6 PHIBT " " " " 7 PBT P at XT,YT,ZT 8 XSC coords at barrel SC entrance 9 YSC " " " " 10 ZSC " " " " 11 THETSC direction of track at XSC,YSC,ZSC 12 PHISC " " " " 13 PSC P at XSC,YSC,ZSC 14 XET coords at end cap TOF plane 15 YET " " " " " 16 ZET " " " " " 17 THETET direction of track at XET,YET,ZET 18 PHIET " " " " " 19 PEC P at XET,YET,ZET 20 XEC coords at end cap SC entrance 21 YEC " " " " " 22 ZEC " " " " " 23 THETEC direction of track at XEC,YEC,ZEC 24 PHIEC " " " " " 25 PEC P at XEC,YEC,ZEC 26 XC coords at coil radius 27 YC " " " " 28 ZC " " " " 29 THETC direction of track at XZ,YC,ZC 30 PHIC " " " " 31 PC P at XC,YC,ZC 32 BTPATH path length from XM,YM to XBT,YBT 33 ETPATH path length from XM,YM to XET,YET Following format is used to specify DECAY points (IVDCAY ne 0) --------- ------ -- ---- -- ------- ----- ------ ------- -- -- 2 IDYCHR charge 0, +1, -1 (9 if sign unknown) 3 PXYDCY at xdcy,ydcy,zdcy 4 PXDCY " " 5 PYDCY " " 6 PZDCY " " 7 PDCY " " 8 THETDY " " 9 PHIDCY " " 10 XDCY coords of decaying track near decay vertex 11 YDCY " " " " " " " 12 ZDCY " " " " " " " 13 DCYLEN 3-D path length of decaying particle (from parent vtx to decay vtx) 13+ 1 ERRDCY error matrix at decay point on track . . " 13+15 . "[top]

J NAME CONTENTS - ---- -------- 1 NWDS number of words this record 2 IRCHRG charge of track, 0, +1, -1 3 RPXY at secondary vertex (starting point coords) 4 RPX " 5 RPY " (note that PZ/P gives cos(THETA), 6 RPZ " PXY/P gives sin(THETA), 7 RP " PX/PXY gives cos(PHI), 8 RTHETA " PY/PXY gives sin(PHI) ..or TANLAM (for new tracking code) 9 RPHI " so use ratios rather than sin/cos 10 RX " to save cpu time). 11 RY " 12 RZ " <=ZDCY-(XY path from IR>cot(RTHETA)) 13 RR " (in XY plane) 14 MRFIT fit method 1=VEEFND, 2=PIZERO 15 RMASS mass of particle 16 RTYPE type of fit 17 RCHISQ chisq of fit 18 RDF degrees of freedom for fit[top]