HT Histograms for Run 10

STAR Offline QA Shift Histogram Description - Run 10

Note:  Not all reference plots may be ideal, be sure to carefully read the descriptions.

This page contains the reference histograms and descriptions for the Offline QA system for Run 10.  These pages should correspond exactly to the jobs viewed in the Offline QA Browser.  However, STAR is a dynamic experiment and the plots generated for QA will change several times throughout the run.  If this reference page seems out-of-date, or if you find a job that would make a better reference, please email the QA hypernews list here.

Other links:

Elizabeth W. Oldag for the QA Team.
January 25, 2010.

Page Index for QA Shift Plots

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  • Page 9
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    1. StEHT event primary vertex check: Primary vertex finding status for run; events with (1) and without (-1) final vertex. The relative fraction of events with primary vertex depends on trigger, beam diamond width and position.

    2. StEHT point: # hits tpc : Distribution of number of reconstructed space points in TPC per event. Should scale with centrality, depends on multiplicity cut and trigger. For high tower triggers this distribution extends to larger hit multiplicities.

    3. StEHT point: # hits ftpc: Not filled in this run. Distribution of number of reconstructed space points in FTPC East (solid line) and West (dashed line) per event. Scales with centrality, depends on multiplicity cut and trigger.

    4. StEHT point: x-y distribution of hits, tpcE: Scatter plot of the azimuthal distribution of reconstructed space points in the East TPC. The distribution should be azimuthally uniform except for the 12 sector structure of the TPC (lighter areas indicate sector boundaries). Density should decrease radially but inner and outer sector structure should be present (darker areas in the innermost pads of the inner and outer sectors). Watch for empty areas (typically masked RDOs) and hot spots. Notify TPC experts if new empty area or hot spot appears.

    5. StEHT point: x-y distribution of hits, tpcW: Scatter plot of the azimuthal distribution of reconstructed space points in the West TPC. The distribution should be azimuthally uniform except for the 12 sector structure of the TPC (lighter areas indicate sector boundaries). Density should decrease radially but inner and outer sector structure should be present (darker areas in the innermost pads of the inner and outer sectors). Watch for empty areas (typically masked RDOs) and hot spots. Notify TPC experts if new empty area or hot spot appears.

    6. StEHT point: r-phi distribution of hits, tpcE: Same as the x-y scatter plot except in polar coordinates.


    1. StEHT point: r-phi distribution of hits, tpcW: Same as the x-y scatter plot except in polar coordinates.

    2. StEHT point: z distribution of hits, tpc: Distribution of reconstructed space points in TPC with respect to z-coordinate. There is a broad peak above the nominally flat background at z=0. This is intentional and is done in order to allow identification of post-trigger pileup events. Watch out for any other anamolous steps or unusual spikes or dips. The peaks just outside |z| = 200 cm are new in Run 10.

    3. StEHT point: #phi distribution of hits, tpc: Distribution of reconstructed space points in TPC with respect to azimuthal coordinate (phi) for east (solid line) and west (dashed line) halves. Should be flat except for the 12-fold sector structure or masked RDOs (as shown). Dead RDO's will produce dips and gaps; hot pads or FEE cards will produce spikes.

    4. StEHT point: padrow distribution of hits, tpc: Distribution of reconstructed space points in TPC with respect to padrow number 1-45. Should display gradual fall-off; watch for anamolous spikes and dips. Missing RDO's cause drops in the distribution. Padrow 13 was restored in Run 9 and continues to be active in Run 10.

    5. StEHT point: x-y distribution of hits, ftpcE: Not filled in this run. Radial distribution of reconstructed space points in FTPC East. The distribution should be uniform except for the insensitive gaps between the six readout sectors. Localized denser areas are due to noise. Ideally noisy pads are flagged in the FTPC gain tables so that they are not used for cluster finding. Less densely populated areas not on the sector boundaries are due to dead electronics. Empty areas not on the sector boundaries indicates a serious hardware problem. An FTPC expert should be contacted immediately if this is seen in fast offline-QA during data taking.

    6. StEHT point: x-y distribution of hits, ftpcW: Not filled in this run. Radial distribution of reconstructed space points in FTPC West. The distribution should be uniform except for the insensitive gaps between the six readout sectors. Localized denser areas are due to noise. Ideally noisy pads are flagged in the FTPC gain tables so that they are not used for cluster finding. Less densely populated areas not on the sector boundaries are due to dead electronics. Empty areas not on the sector boundaries indicates a serious hardware problem. An FTPC expert should be contacted immediately if this is seen in fast offline-QA during data taking.


    1. StEHT point: plane distribution of hits, ftpc: Not filled in this run. Number of reconstructed space points assigned to tracks in FTPC East (solid line) and West (dashed line) in each padrow. The horizontal axis shows padrow numbers where FTPC-West is 1-10 and FTPC-East is 11-20. Padrows #1 and #11 are closest to the center of STAR. East and West should be similar in shape but West will have less magnitude than east for d+Au. Spikes indicate noisy electronics; dips indicate dead electronics.

    2. StEHT point: #pads vs #timebins of hits, ftpcE: Not filled in this run. Monitors the cluster quality in FTPC East. Ideally the clusters should have a pad length of 3-5 and a timebin length of 4-6. A prominent peak located at (2,2) indicates bad gas or loss of gain or excessive background.

    3. StEHT point: #pads vs #timebins of hits, ftpcW: Not filled in this run. Monitors the cluster quality in FTPC West. Ideally the clusters should have a pad length of 3-5 and a timebin length of 4-6. A prominent peak located at (2,2) indicates bad gas or loss of gain or excessive background.

    4. StEHT Number hits in cluster for bemc: Distribution of number of BEMC towers contributing to energy clusters.

    5. StEHT Energy of cluster for bemc: Distribution of energy in reconstructed clusters in EMC barrel. Should be peaked with a smooth fall off for minbias data but may display other peaks or structures for other triggers. For high tower triggers there may be excess counts in the large energy tails.

    6. StEHT Eta of clusters for bemc: Azimuthally integrated pseudorapidity distribution of reconstructed energy clusters in the EMC-barrel. Note there will be gaps due to missing and/or uninstrumented sectors. Report any unexpected gaps or unusual spikes. For Run 10 the full barrel is instrumented. The distribution should nominally be flat.


    1. StEHT Phi of clusters for bemc: Pseudorapidity integrated azimuthal distribution (radians) of reconstructed energy clusters in the EMC-barrel. Note there will be gaps due to missing and/or uninstrumented sectors. Report any unexpected gaps, unusual spikes, or sections of significantly elevated yields.

    2. StEHT Number hits in cluster for bsmde: Distribution of numbers of hits (anodes) contributing to Barrel SMD clusters along pseudorapidity.

    3. StEHT Eta of clusters for bsmde: Pseudorapidity distribution of reconstructed energy clusters in the BSMD anode grid along pseudorapidity. Note there will be gaps due to missing and/or uninstrumented sectors. Report any unexpected gaps or unusual spikes. Distribution should nominally be flat.

    4. StEHT Number hits in cluster for bsmdp: Distribution of numbers of hits (anodes) contributing to Barrel SMD clusters along azimuth.

    5. StEHT Phi of clusters for bsmdp: Azimuthal distribution of reconstructed energy clusters in the BSMD anode grid along azimuth angle (phi in radians). Note there will be gaps due to missing and/or uninstrumented sectors. Report any unexpected gaps or unusual spikes.

    6. StEHT EmcCat4 Point Energy: Energy distribution for Barrel EMC-SMD Category 4 clusters. Cat4 clusters correspond to TPC track matched clusters in the EMC barrel, BSMD-eta and BSMD-phi detectors.


    1. StEHT EmcCat4 Point Eta: Pseudorapidity distribution for EMC-SMD Category 4 clusters. Distribution should nominally be flat.

    2. StEHT EmcCat4 Point Phi: Azimuthal distribution for EMC-SMD Category 4 clusters. Distribution should nominally be flat.

    3. StEHT EmcCat4 Sigma Eta: Distribution of widths (sigma) of Category 4 Barrel EMC-SMD clusters with respect to pseudorapidity.

    4. StEHT EmcCat4 Sigma Phi: Distribution of widths (sigma) of Category 4 Barrel EMC-SMD clusters with respect to azimuthal angle.

    5. StEHT EmcCat4 Delta Eta: Differences between centroids of Category 4 Barrel EMC-SMD clusters and projected positions of TPC tracks at BEMC with respect to pseudorapidity. Should be peaked at ~0. Not filled in Run 10.

    6. StEHT EmcCat4 Delta Phi: Differences between centroids of Category 4 Barrel EMC-SMD clusters and projected positions of TPC tracks at BEMC with respect to azimuthal angle. Should be peaked at ~0. Not filled in Run 10.


    1. StEHT EmcCat4 Points Multiplicity: Frequency distribution of number of Category 4 clusters per event. For high tower triggers this distribution extends to larger multiplicities.

    2. StEHT EmcCat4 Track Momenta : Distribution of TPC global track momentum for Barrel EMC-SMD Category 4 clusters. Not filled in Run 10.

    3. StEHT Point Flag: Distribution of Barrel EMC and SMD cluster types by Category number. There should be a reasonable fraction of Cat4 clusters as in this example histogram; report if this fraction drops significantly. For high tower triggers the relative fraction of Cat4 clusters should be larger than in MinBias.

    4. StEHT globtrk: iflag - all : Quality flag values for all global tracks. Some with large, negative values may not appear on plot; check stat. box for underflows. Majority of tracks should have iflag>0, corresponding to good, usable tracks. Refer to: dst_track_flags.html and kalerr.html for description of flag values. Note that in Runs 7-10 about half the tracks have iflag < 0.

    5. StEHT globtrk: tot good tracks - all: Distribution of the number of good global tracks in the TPC per trigger; including pileup. For high tower triggers this distribution extends to larger track multiplicities.

    6. StEHT globtrk: tot good tracks - ftpc: Not filled in this run. Scatter plot of good global track multiplicities in FTPC West versus FTPC East.


    1. StEHT globtrk: Detector ID good tracks - all: Global track detector IDs for good tracks. Refer to: /afs/rhic/star/packages/DEV00/pams/global/inc/StDetectorDefinitions.h for Detector ID codes.

    2. StEHT globtrk: z-DCA to Beam Axis, coarse scale: Coarse scale distribution along the z-axis (from -200 to +200 cm) of the DCA points to the nominal beam line (z-axis, x=y=0) for all TPC global tracks. Peaks indicate probable locations of individual collision vertices however indentification of individual collision vertices is unlikely.

    3. StEHT globtrk: z-DCA to Beam Axis: Fine scale distribution along the z-axis (from -50 to +50 cm) of the DCA points to the nominal beam line (z-axis, x=y=0) for all TPC global tracks. Peaks indicate probable locations of individual collision vertices.

    4. StEHT globtrk: z-DCA to Beam Axis vs tanl, tpc: Scatter plot of the tangent of the dip angle (tanl) versus the z-coordinate (from -25 to 25 cm) of the DCA points to the nominal beam line (z-axis, x=y=0) for all TPC global tracks. Vertical bands should be seen corresponding to individual events. The bands should be smooth and continuous; breaks at tanl=0 indicate probable TPC calibration errors in either the t0 offset or the drift speed. This is best seen for high multiplicity events. Cross reference for calibration errors with z-DCA to beam axis versus z-coord. of first hit on track.

    5. StEHT globtrk: z-DCA to Beam Axis vs z-first: Scatter plot of the z-coordinate of the first fitted hit in the TPC versus the z-coordinate (from -25 to 25 cm) of the DCA points to the nominal beam line (z-axis, x=y=0) for all TPC-only global in which the first point used in the fit lies in the TPC. Vertical bands should be seen corresponding to individual events. The bands should be smooth and continuous; breaks at z=0 indicate TPC calibration errors in either the t0 offset or the drift speed. This is best seen for high multiplicity events.

    6. StEHT globtrk: z-DCA to Beam Axis vs psi: Scatter plot of the azimuthal direction angle (psi) versus the z-coordinate (from -25 to 25 cm) of the DCA points to the nominal beam line (z-axis, x=y=0) for all TPC global tracks. Vertical bands should be seen corresponding to individual events. The bands should be smooth, straight and continuous indicating azimuthal symmetry in the tracking. Bends or offsets could indicate problems in individual TPC sectors such as voltage sags or drifts. These are best studied with high multiplicity events.


    1. StEHT globtrk: padrow of first hit on trk, tpc: Distribution of first fitted space point with respect to pad row number for TPC-only global tracks. Should peak at 1 with a minor peak at padrow 14 (beginning of outer sector); the latter should not be too big relative to that at row 1. Other peaks may indicate large, missing sections of the TPC read-out causing breaks, and consequently additional, false new starting points for tracks. The excess data for TPC west beyond padrow 35 is due to EEMC tracking needs.

    2. StEHT globtrk: z of first hit on trk, tpc: Distribution of first fitted space point with respect to z for TPC-only global tracks. Should be approx. symmetric.

    3. StEHT globtrk: first point: hit - helix, tpc: Residuals at FIRST point on track for TPC-only global tracks. The quantities plotted are the longitudinal (along z-axis, dashed line) and transverse (in x-y plane, solid line) differences between the coordinates of the first hit and the DCA point on the helix fit to the first point. For the transverse residual, positive (negative) values correspond to hits inside (outside) the circular projection of the helix onto the bend plane. FWHM should be less than ~ 1cm.

    4. StEHT globtrk: phi of first point on trk, tpc: Distribution of first fitted space point with respect to azimuthal angle (phi) for TPC-only global tracks. The solid (dashed) line is for the east (west) half of the TPC. These should be approximately equal and flat within statistics, except for the 12-sector structure.

    5. StEHT globtrk: chisq0, tpc: Chi-square per degree of freedom for TPC global tracks. Should peak just below 1.

    6. StEHT globtrk: signed impact param from prim vtx, tpc: Two-dimensional (2D) (in the transverse plane) signed impact parameter (in cm) from primary vertex for East (solid line), West (dashed line) and All (dotted line) TPC-only global tracks. Should be centered at zero depending on the TPC calibration status used in fast-offline QA production.


    1. StEHT globtrk: tanl(dip) vs. (zfirst-zvtx)/arc length, tpc,tpc+svt: Scatter plot of tangent of dip angle (tanl) versus (z_first - z_primvrtx)/arc-length for TPC-only global tracks whose first fitted point is in the TPC. Variable 'z_first' is the z coordinate of the first fitted point in the TPC. Variable 'z_primvrtx' is the z-coordinate of the primary vertex for the event. Variable 'arc-length' is 2R*arcsin(delta_r/2R) where R = track radius of curvature and delta_r is the transverse distance between the primary vertex and the first hit on track. Primary tracks lie along the 45 deg diagonal. Secondary tracks and strays lie scattered to either side. The diagonal band should appear clearly and be straight and smooth without kinks, breaks or bends.

    2. StEHT globtrk: N points on trk,ftpc: Not filled in Run 10. Distribution of the number of fitted points on track for FTPC-East (solid line) and FTPC-West (dashed line) global tracks. Distributions should be similar except fewer tracks for west than east. Also depends on the relative fraction of active readout in each detector.

    3. StEHT globtrk: psi, ftpc: Not filled in Run 10. Azimuthal distributions for track direction angle (psi) for FTPC-East (solid line) and FTPC-West (dashed line) global tracks. These should be flat within statistics except for the hexagonal FTPC sector structure. There will be fewer west tracks than east for d+Au.

    4. StEHT globtrk: |eta|, ftpc: Not filled in Run 10. Distributions of absolute value of pseudorapidity for FTPC-East (solid line) and FTPC-West (dashed line) global tracks. These should be similar (modulo for d+Au) and range from about 2.5 to 4.5.

    5. StEHT globtrk: pT, ftpc: Not filled in Run 10. Transverse momentum (GeV/c) distributions for FTPC-East (solid line) and FTPC-West (dashed line) global tracks. These should be similar (modulo d+Au)within statistics.

    6. StEHT globtrk: momentum, ftpc: Not filled in Run 10. Total momentum (GeV/c) distributions for FTPC-East (solid line) and FTPC-West (dashed line) global tracks. These should be similar (modulo d+Au) within statistics.


    1. StEHT globtrk: impact param from prim vtx, ftpc: Not filled in Run 10. Distribution of impact parameter values for global FTPC East tracks (solid curve) and West tracks (dashed curve) with respect to the main TPC global track determined primary vertex.

    2. StEHT globtrk: Y vs X of first hit on trk, ftpcE: Not filled in Run 10. Scatter plot of (x,y) coordinates for the first fitted space points in FTPC-East global tracks. These should be uniformly populated with hits; FTPC hexagonal structure is apparent.

    3. StEHT globtrk: Y vs X of first hit on trk, ftpcW: Not filled in Run 10. Scatter plot of (x,y) coordinates for the first fitted space points in FTPC-West global tracks. These should be uniformly populated with hits; FTPC hexagonal structure is apparent.

    4. StEHT primtrk: iflag - all: Quality flag values for all primary tracks. Some with large, negative values may not appear on plot; check stat. box for underflows. Majority of tracks should have iflag>0, corresponding to good, usable tracks. Refer to: dst_track_flags.html and kalerr.html for description of flag values.

    5. StEHT primtrk: tot num tracks iflag>0: Distribution of total number of primary tracks per triggered event. For high tower triggers this distribution extends to larger track multiplicities.

    6. StEHT primtrk: ratio primary/global tracks w/ iflag>0: Ratio of good primary to good global tracks for all detectors. For Au-Au this ratio usually peaks at about 0.5.


    1. StEHT primtrk: , ftpc: Not filled in Run 10. Transverse momentum (GeV/c) distributions for FTPC-East (solid line) and FTPC-West (dashed line) primary tracks. These should be similar within statistics.

    2. StEHT primtrk: ||, ftpc: Not filled in Run 10. Distributions of absolute value of mean pseudorapidity for FTPC-East (solid line) and FTPC-West (dashed line) primary tracks. These should be similar within statistics and range from about 2.5 to 3.5.

    3. StEHT primtrk: first point: hit - helix (r,z), tpc: Residuals at first point on track for TPC-only primary tracks. The quantities plotted are the longitudinal (along z-axis, dashed line) and transverse (in x-y plane, solid line) differences between the coordinates of the first hit and the DCA point on the helix fit to the first point. For the transverse residual, positive (negative) values correspond to hits inside (outside) the circular projection of the helix onto the bend plane. FWHM should be less than ~ 1cm.

    4. StEHT primtrk: |eta|, ftpc: Not filled in Run 10. Distributions of absolute value of mean pseudorapidity for FTPC-East (solid line) and FTPC-West (dashed line) primary tracks. These should be similar within statistics and range from about 2.5 to 3.5.

    5. StEHT primtrk: pT, ftpc: Not filled in Run 10. Transverse momentum (GeV/c) distributions for FTPC-East (solid line) and FTPC-West (dashed line) primary tracks. These should be similar within statistics.

    6. StEHT dedx: ratio mean to Bethe Bloch , tpc,tpc+svt: Distribution of ratio of mean dE/dx to Bethe-Bloch dE/dx for pions at the same momentum for TPC-only global tracks. Should peak at ~1. Tests calibration of charge deposition in TPC gas.


    1. StEHT PID: globtrk-dst_dedx, p vs dedx (reconstructed): Scatter plot of truncated mean dE/dx versus total momentum (GeV/c) for TPC-only global tracks. Should be able to see Bethe-Bloch bands for pions, kaons and protons if statistics are sufficient.

    2. StEHT vertex,prim: z : Distribution of primary vertex position along the z-axis out to abs(z) < 50 cm.

    3. StEHT vertex,prim: x versus y: Scatter plot of the (x,y) coordinates of the primary vertex position. This should correspond to the determined beam transverse position. The amount of dispersion will depend on the trigger condition and multiplicity cuts.

    4. StEHT vertex,prim: x(ftpcE)-x(tpc) vs y(ftpcE)-y(tpc): Not filled in Run 10. Scatter plot of the differences in x-y position (cm) for primary vertex positions determined by FTPC East global tracks and main TPC glbtrks. Should scatter about (0,0).

    5. StEHT vertex,prim: z(ftpcE)-z(tpc): Not filled in Run 10. Distribution of the differences along the z-axis, i.e. beam direction, in cm for primary vertex positions determined by FTPC East global tracks and main TPC glbtrks. The mean should be near 0.

    6. StEHT vertex,prim: x(ftpcW)-x(tpc) vs y(ftpcW)-y(tpc): Not filled in Run 10. Scatter plot of the differences in x-y position (cm) for primary vertex positions determined by FTPC West global tracks and main TPC glbtrks. Should scatter about (0,0).


    1. StEHT vertex,prim: z(ftpcW)-z(tpc): Not filled in Run 10. Distribution of the differences along the z-axis, i.e. beam direction, in cm for primary vertex positions determined by FTPC West global tracks and main TPC glbtrks. The mean should be near 0.