1 / 11

FD Crosstalk or A disappointing lack of pretty colours

FD Crosstalk or A disappointing lack of pretty colours. Philip Rodrigues Oxford MINOS Meeting 20 May 2008. Why care?. Something wrong with detector modelling in FD:. ND. FD. Affects CC variable:. xtalk +10%. Nominal. Why care? 2. Given low priority by CC group…

yen
Download Presentation

FD Crosstalk or A disappointing lack of pretty colours

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. FD CrosstalkorA disappointing lack of pretty colours Philip Rodrigues Oxford MINOS Meeting 20 May 2008

  2. Why care? • Something wrong with detector modelling in FD: ND FD • Affects CC variable: xtalk +10% Nominal

  3. Why care? 2 • Given low priority by CC group… • …but nue particularly sensitive to detector modelling: • Eg docdb 4578: 10-20% change in selected events with 35% xtalk change

  4. Method • Want prob. that “true” hit on pixel j creates xtalk hit on pixel i: • Ideally, identify xtalk hits and true hits. Only possible on test stand • Best idea so far: • hits <3pe are used as xtalk • track hits >3pe as “true” hits • In principle, mismodelling P(true) cancels(?), but err on the side of conservatism

  5. More method • Use cosmics for high stats • Restrict to few hits in plane by requiring dcosz > 0.6 • Require 10 strips in event, no shower • Daikon 03 MC, MC and data reco’d with cedar_phy_bhcurv • Loop over all strips in detector • Try using muxing pattern to separate out xtalk and physics

  6. (De)Muxing Tubes 0,2: Crosstalk + Physics Tube 1: Crosstalk only

  7. Sanity Check – no-xtalk MC • Reco some MC cosmics without crosstalk • Should get zeros everywhere: • Don’t get zeros. Significant physics contribution • Only small differences between tubes

  8. Vetoing Physics • Assume physics modelling entirely correct, then: • and xtalk scale factor is:

  9. Result • Generally NN high, diag low in data, but not entirely • Some differences between 1 and 0,2 • Errors are still a bit big (~0.02 in NN, 0.1 in diag) • Working on more stats

  10. Result 2 • Histogram values in NN and diagonal pixel pairs • NN about 1, diag about 1.3

  11. Provisional Conclusions and TODO • NN crosstalk about right, diag too low • ~Same conclusion as nue group • Further checks: • Alter cuts, check numbers come out the same • TODO: • Rerun with increased stats • Use scale factors in DetSim crosstalk model

More Related