1 / 9

ECAL2. Fighting against faulty gammas after the reconstruction (phast level)

ECAL2. Fighting against faulty gammas after the reconstruction (phast level). A.Lednev Calorimetry meeting 26.10.2010. killgamma. In the reconstruction there is a procedure (killgamma) which is trying: To suppress noisy channels. To minimize number of artificially created false gammas.

brook
Download Presentation

ECAL2. Fighting against faulty gammas after the reconstruction (phast level)

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. ECAL2.Fighting against faulty gammasafter the reconstruction(phast level) A.Lednev Calorimetry meeting 26.10.2010

  2. killgamma In the reconstruction there is a procedure (killgamma) which is trying: • To suppress noisy channels. • To minimize number of artificially created false gammas. False gamma may be created by shower profile fit if cell energy fluctuations are too large. Parameters in killgamma procedure during the reconstruction were the following: • If gamma energy is less than 0.2 GeV the gamma is killed. • If the effective mass of 2 gamma is less than 40 MeV and distance between them if less than 10 cm these gammas are glued. Such criteria seems to be too soft and for physical analysis it would be better to use stronger parameters. That is possible to make at the level of phast. Run 81701 (Primakoff) was used to check this procedure.

  3. Gamma energy thresholds Upper figure shows the gamma distribution in ECAL2. The same distribution for gamma energy Eg > 1 GeV and Eg > 2 GeV are shown in the next figures. Number of noisy channels are less.

  4. Gluing of gammas Left figure shows masses of 2 gamma combinations versus distance between them. All events are used there. Central figure is the same for 3 gamma events. Right figure shows this distribution for 3 gamma events and killgamma parameters: Gammas with distance between them < 14 cm and mgg < 90 MeV are glued.

  5. killgamma parameters Number of gammas with original (black histogram) and new gluing parameters of killgamma with Eg > 1 Gev (red hist) and Eg > 2 GeV (green) are shown.

  6. killgamma parameters Masses of 2 gamma combinations from all events for original and new gluing killgamma parameters for Eg > 1 GeV and Eg > 2 GeV .

  7. killgamma parameters Masses of all 2 gamma events (left) and 2 gamma events with Etot > 180GeV(right) events for original (black) and newkillgamma gluing parameters. Eg > 1 GeV and Eg > 2 GeV .

  8. killgamma parameters Masses of 2 gamma combinations from 3 gamma events with Etot > 180GeV . for original (black) and newkillgamma gluing parameters. Eg > 1 GeV and Eg > 2 GeV

  9. Summary Parameters in killgamma in coral are too soft for physics analysis. It would be better to use additional gamma energy threshold and gluing parameters at the level of phast. Preferable values for these parameters depend on physics and need to be chosen during analysis.

More Related