K. Kainz's transparencies from July 1999 collaboration meeting at BNL

Slides 1 through 20 below were incorporated into the presentation of TOF analysis status during the Friday AM session.

Slide 1 is a title page for the TOF analysis status talk. An outline of the talk is presented here.

Slide 2 is a brief update on the platform used at Rice, the revisions to the extrapolation and slat-to-track matching software, and the UTA Pass II code.

[Scanned JPEG version of slide 2]

[Postscript version of slide 2 -- illustration is not included]

Slide 3 describes the events used in the TOF alignment study, the goals of the optimization, and the geometry and field quantities to consider.

[Scanned JPEG version of slide 3]

[Postscript version of slide 3 -- illustration is not included]

Slide 4 shows, for the two p98 runs used in the alignment sudy, the regions of the TOF array where the tracks strike, and the distribution of DDC wires hit per track. For the wire-hit-per-track distributions, the dotted line denotes 80 wire hits per track.

[Postscript version of slide 4]

Slide 5 lists the geometry and field values used prior to the DDC wiremap rotation, and shows the extrapolator accuracy (extrapolator estimate minus actual TOF hole hit by track) versus the actual TOF hole hit. For the central wall slats, the extrapolator accuracy is about one slat width (1.7 cm); about 30 percent of the time, then, the extraplator estimate may be one or two slats away from the actual TOF hole hit.

[Scanned JPEG version of slide 5]

[Postscript version of slide 5 -- handwritten comments are missing]

Slide 6 shows the effect of rotating both the DDC wiremap and the TOF geometry about the same axis (x = -42.174, z = 498.701) and the same angle (3.79 mrad). NOTE: a TOF geometry rotation to match the DDC wiremap rotation is not appropriate. The wiremap rotation corrects a problem with the DDC frame with respect to the 48D48 magnet; there is no problem with the cave coordinate system as a whole.

[Postscript version of slide 6]

Slide 7 shows the effect of applying an additional translation of the central wall slats in the -x direction, so as to center the extrapolation accuracies over all slats at zero.

[Scanned JPEG version of slide 7]

Slide 8 addresses the problem of background in any slat-to-track matching for Au98 data. A tool to evaluate the quality of a TOF slat match to a DDC track is introduced. This tool uses the correspondence between y from the extrapolator and y implied by the difference between the slat's TDCs.

[Postscript version of slide 8]

Slide 9 defines two slat-to-track matching efficiencies. The "correctness of match" efficiency gives the likelihood that the slat to track match was correct. The "slat existence" efficiency is the probability that the extrapolated track will have a TOF hit with which to match it.

[Scanned JPEG version of slide 9]

[Postscript version of slide 9 -- the hand-drawn illustration is not included]

Slide 10 describes two different algorithms employed in the Au98 slat-to-track matching tests. A simple method looks only for a TOF hit at the same hole as the extrapolator estimate. A more complex method checks the TOF slats that are one or two holes away from the extrapolator estimate as well.

[Scanned JPEG version of slide 10]

[Postscript version of slide 10 -- hand-drawn illustrations are not included]

Slide 11 shows the slat-existence efficiency, the correctness-of-match efficiency, the overall slat-to-track match efficiency, and the signal-to-background ratio, each versus the extrapolator estimate, for the simple and complex matching methods. For these plots, no cuts were made regarding the track quality, track momentum, or the location of the track at z = 253 cm.

[Postscript version of slide 11]

Slide 12 shows the tracking y vs TDC difference (bottom minus top), along with the difference between the tracking y and the y coordinate predicted by the TDC difference, for TOF hole 68. At this location, both the correctness-of-match efficiency and the signal-to-background ratio are quite high, as was seen in Slide 11.

[Postscript version of slide 12]

Slide 13 presents the wire-hit-per-track distribution for Au98 tracks, and shows the effect of a track-quality cut (requiring over 80 wire hits per track) upon the correctness-of-match efficiency.

[Postscript version of slide 13]

Slide 14 shows the slat-existence efficiency, the correctness-of-match efficiency, and the overall slat-to-track match efficiency of Au98 tracks with over 80 DDC wires hit per track.

[Postscript version of slide 14]

Slide 15 shows the distribution uopn the TOF array of positive and negative Au98 tracks, both without and with the "over 80 wire hits per track" cut. The beam-left Rice wall is the only place where high-quality negative tracks can be found.

[Postscript version of slide 15]

Slide 16 shows the correctness-of-match efficiency for four different track-momentum cuts. A high correlation between the track momentum and its location upon the TOF array can be observed.

[Postscript version of slide 16]

Slide 17 restates the extrapolator accuracy seen in p98 data, and introduces the notion that a simialr extrapolator accuracy should also be extracted from Au98 data.

[Scanned JPEG version of slide 17]

Slide 18 shows the percentage of slat-to-track matches versus the difference between the extrapolator estimate and the actual TOF hole hit, for: 1) p98 tracks upon hole 120; 2) Au98 tracks upon hole 120; 3) Au98 tracks upon hole 120, with a cut on matches where the "delta-y" is within +/- 3 sigma of its mean; and 4) Au98 tracks upon hole 120, with the 3-sigma cut, and an attempted subtraction of the "mismatches mistaken for good matches" applied as well.

[Scanned JPEG version of slide 18 -- a table summarizing match probability versus slat shift is written on the bottom of the slide]

[Postscript version of slide 18]

Slide 19 summarizes the results presented in this talk.

[Scanned JPEG version of slide 19]

Slide 20 presents the immedite TOF analysis joblist.

[Postscript version of slide 20]

Slides 21 and 22 were shown during the Friday session's discussion of target-location verification.

Slide 21 shows the x and y distributions of Au98 tracks extrapolated upstream to z = 253 cm. The new DDC wiremap is used, but a box-field estimate of 14.83 kG is used to calculate the track momentum.

[Postscript version of slide 21]

Slide 22 shows the momentum distribution for both positive and negative Au98 tracks that originate from the target.

[Postscript version of slide 22]