Standard AnalysisNtuple Variables

Introduction

The variables from the Analysis Ntuple are presented here grouped by tool. Within each tool, variables are arranged roughly according to their position in the ntuple.

Unless otherwise noted, energy is in MeV, length is in mm, and angle is in radians. Also, unless otherwised noted, the null value, that is, the value in the ntuple when there is no calculated value for a given variable, is zero.

The variables may be of type Int, Unsigned int, Float, Double or String. Currently, for reasons of history, most are floats, even those that take only integer values.

(A "string" is a null-terminated character array. The default value is "_".)

CalValsTool Variables

Variable Type Description
CalEnergyRaw F Sum of the raw energies in all the crystals. Includes estimate of missed energy due to zero-supression. This replaces the variable CalEnergySum. NEW!
CalEnergyCorr F Cal Energy corrected layer-by-layer for edges and leakage. This replaces the variable CalEneSumCorr. NEW!
CalLeakCorr F Leakage correction: this is the contained fraction of the total energy after edge corrections.
CalEdgeCorr F Effective layer-by-layer edge correction mainly due to the gaps between Cal modules; multiplicative
CalTotalCorr F Global total correction. Includes effect due to dead material; multiplicative
CalCsIRLn F Total radiation lengths in crystals, integrated along the event axis (line connecting the first hit in the tracker to the CAL energy centroid)
CalTotRLn F Total radiation lengths in the CAL, integrated along the event axis.
CalCntRLn F Radiation lengths integrated along the event axis, up to energy centroid
CalLATRLn F Total radiation lengths integrated along the event axis (including the tracker).
CalDeadTotRat F Ratio of radiation lengths in dead material to CalTotRLn
CalDeadCntRat F Ratio of radiation lengths in dead material up to energy centroid, to CalCntRat
CalTPred F Model-predicted energy centroid in radiation lengths
CalDeltaT F Difference between measured and predicted energy centroids
CalTwrEdge F Distance of the entry point of the best track from the tower boundary, measured at the top of the CAL.
CalLATEdge F Closest distance of track 1, projected to the top of the CAL, to the edge of the CAL layer, taking non-square shape into account. This is essentially the old merit skirt variable.
CalEdgeEnergy F The sum of the raw energies in each crystal for which the energy centroid is within _deltaEdge (currently 50 mm) of the outside edge of one of the outside CAL modules. This is an attempt at a "anti-coincidence counter" for the CAL.
CalTwrEdgeCntr F Distance of the energy centroid from the nearest tower boundary.
CalGapFraction F Approximate fraction of the shower volumn which falls in inter-tower gaps.
CalTrackSep F Distance between impact points of two best tracks at CAL front face; zero if only one track
CalTrackDoca F Distance between the projected vertex (or track if only one track) and the energy centroid, evaluated at the z of the centroid.
CalTrackAngle F Angle between "gamma" direction in the tracker and direction of the CAL "track"
CalELayerN, N=0,7 F Energy deposited in layer N of the CAL
CalLyr0Ratio F Ratio of CalELayer0 to CalEnergyRaw
CalLyr7Ratio F Ratio of CalELayer7 to CalEnergyRaw
CalBkHalfRatio F Ratio of total energy in back half of CAL (layers 4-7) to CalEnergyRaw
CalXtalsTrunc F Number of CAL Xtals with > 1 of CalEnergyRaw (see CalXtalRatio)
CalXtalRatio F Ratio of number of Xtals with energy > 1% of CalEnergyRaw to total number of struck Xtals in the event.
CalXtalMaxEne F Maximum energy found in a single Xtal
CalLongRms F rms of the average of the 1st and 3rd shower moments. Indicates the length of the measured shower along the shower axis.
CalLRmsAsym F The asymetry of the 1st and 3rd shower moments. This should be close to zero. Because of ordering of moments it is slightly ... (??)
CalTransRms F rms of transverse position measurements.
CalMIPDiff F Difference between measured energy and that expected from a minimum-ionizing particle
CalMIPRatio F Ratio of measured energy to that expected from a minimum-ionizing particle
Cal[X/Y/Z]Ecntr F Energy centroid in [x/y/z]
Cal[X/Y/Z]Dir F [x/y/z] direction cosine of CAL "track"
Cal[X/Y]0 F [x/y] position of CAL "track" measured at the energy centroid
CalTrkXtalRms F For this and the next three variables, a measure of the rms spread of the crystals in the calorimeter around the projection of the first track. They differ by the weighting and crystal count. This one is the rms of the DOCAs of all crystals with repect to the projected track
CalTrkXtalRmsE F Same as the previous, but weighted by the deposited energy in each crystal
CalTrkXtalRmsTrunc F Same as the first, but excludes the crystals with the largest DOCAs. Default is to remove 10% of the crystals, with the number of crystals included rounded to the nearest integer
CalTrkXtalRmsETrunc F Same as the previous, but weighted by the deposited energy in each crystal
CalRmsLayerE F Rms of deposited energy (normalized to rad. lengths traversed, and to average energy deposited) for all the layers with > 5% of deposited raw energy and at least 0.5 rad lengths of predicted CsI traversed.
CalRmsLayerEBack F Same as above, with layer 0 left out of the calculation
CalNLayersRmsBacj I Number of layers used in the calculation of CalRmsLayerEBack above
CalEAveBack F Average of normalized eDep excluding layer 0, cuts as for CalRmsLayerE above
CalLayer0Ratio F Ratio of layer0 normalized eDep to the average of the remaining layers, cuts as for CalRmsLayerE above
Cal[X/Y]PosRmsLL F Energy Weighted Rms of the hit crystals in the last layer (layer 7). X is measured across the width of the crystals, Y across the length.

VtxValsTool Variables

In what follows below, whenever the first 2 vertices are referenced, they will be called "Vtx" and "Vtx2". This is to maintain backward compatibility with existing code.

Variable Type Description
VtxNumVertices I Number of vertices in the event
Vtx[/2][X/Y/Z]Dir F [x/y/z] direction cosine of the vertex: the first is "Vtx"; the 2nd, if present, is "Vtx2".
VtxPhi F Azimuthal angle of vertex, radians (direction of source, not flight direction!) Range: (0,2pi)
VtxTheta F Polar angle of vertex, radians (ditto direction)
VtxThetaErr F Error on the measurement of theta
VtxPhiErr F Error on the measurement of phi.
VtxS[XX/YY] F [x-x/y-y] element of the covariance matrix; square of error on [x/y]
VtxSXY F x-y element of the covariance matrix; covariance
Vtx[/2][X/Y/Z]0 F [x/y/z] coordinate of vertex The first vertex is "Vtx"; the 2nd, if present, is "Vtx2". If the two tracks making up the vertex are nearly parallel, the coordinates of the vertex may become very large.
Vtx2TransDoca
Vtx[/2]Angle F Angle between the two tracks of the vertex (radians); the first vertex is "Vtx"; the 2nd, if present, is "Vtx2".
Vtx[/2]DOCA F Distance of closest approach between the two tracks; the first vertex is "Vtx"; the 2nd, if present, is "Vtx2".
Vtx[/2]HeadSep F Distance between the heads of the two tracks; the first vertex is "Vtx"; the 2nd, if present, is "Vtx2".
Vtx2LongDoca F Longitudinal distance of the 2nd vertex along the axis of the first vertex; positive if the 2nd vertex is below the first.
Vtx2TransDoca F Transverse distance of the 2nd vertex point from the axis of the first vertex
Vtx[/2]Status F Summary of track composition and topology. See TkrVertex.h in the Event package for the current description. The definitions as of GR v7r2 are:
    |  0   0   0   0  |  0   0   0   0  |  0   0   0   0  |  0   0   0   0   |
                                         [Track Topology ] [Track composition]

    ONETKRVTX = 0x0001,  //Set if single track vertex
    TWOTKRVTX = 0x0002,  //Set if 2 track vertex
    MULTKRVTX = 0x0004,  //Set if >2 track vertex
    DOCAVTX   = 0x0010,  //Set if vertex location set by DOCA point
    FIRSTHIT  = 0x0020,  //Set if two tracks share first hit
    STAGVTX   = 0x0040,  //Set if tracks don't start in same plane (staggered)
    CROSSTKR  = 0x0080   //Set if DOCA location lies inside track hits

VtxQuality F Vertex quality parameter used to order the possible vertices and select the best one. Should generally not be used in analysis.
VtxChisq F The covariant chi-squared for the pairing of the tracks.
VtxS[1/2] F Distance of DOCA point from head of track [1/2]
VtxAddedRL F The additional radiation lengths prior to the first measured silicon strip hit at the vertex location. New!


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