Hyperon simulations
This presentation is the property of its rightful owner.
Sponsored Links
1 / 19

Hyperon simulations PowerPoint PPT Presentation


  • 75 Views
  • Uploaded on
  • Presentation posted in: General

Hyperon simulations. E. Kryshen (PNPI, SPbSPU) Ya. Berdnikov (SPbSPU). Charged decays. CBMROOT framework OCT04 UrQMD central events 25 AGeV Magnetic field v03b Strip hits with 10 μ m resolution No particle ID is assumed Ideal track finding (at least 4 MC points)

Download Presentation

Hyperon simulations

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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Hyperon simulations

Hyperon simulations

E. Kryshen (PNPI, SPbSPU)

Ya. Berdnikov (SPbSPU)


Charged decays

Charged decays

CBM Collaboration meeting


Hyperon simulations

CBMROOT framework OCT04

UrQMD central events 25 AGeV

Magnetic field v03b

Strip hits with 10 μm resolution

No particle ID is assumed

Ideal track finding (at least 4 MC points)

Momentum and vertex reconstruction with Kalman filter 4-order Runge-Kutta extrapolation in magnetic field(Resolution on daughter momentum: ~ 0.6%)

Event mixing used for - and -background simulation

- and - signal was generated in accordance with UrQMD pt-y distributions

Simulation framework

CBM Collaboration meeting


Acceptance

Acceptance

--

Total for :15.8%

Total for :6.7%

Total for :7.7%

CBM Collaboration meeting


Signal distribution

Signal distribution

--

 = 0.78 MeV

 = 0.90 MeV

 = 1.02 MeV

CBM Collaboration meeting


Secondary vertex resolution

Secondary vertex resolution

  • Z-vertex resolution:

  • :0.34 mm

  • :0.44 mm

  • :0.36 mm

CBM Collaboration meeting


Applying cuts

Applying cuts

  • The following variables were considered to cut the background:

  • bpp – impact parameter of accepted particles

  • pca – z position of secondary vertex

  • dca – distance of closest approach

  • bla – impact parameter of pair momentum

Background c+c-, no cuts

Statistics: 500 events

CBM Collaboration meeting


Illustration of cut parameters

Illustration of cut parameters

CBM Collaboration meeting


Illustration of pair impact parameter cut

Illustration of pair impact parameter cut

CBM Collaboration meeting


Cut parameter distributions

Cut parameter distributions

Distance of closest approach

Impact parameter for positive tracks

All pairs

All positive

protons

 pairs

CBM Collaboration meeting


Hyperon simulations

Optimised cut parameters, 

Statistics: 104 events

CBM Collaboration meeting


Selection of candidates

Selection of  candidates

  • Cuts:

  • Impact parameter cut for positive and negative particles (0.05 cm)

  • Invariant mass cut in the range 2, =0.78 MeV/c2

  • Efficiency:

  • -:83.3 %

  • -:81.9 %

  • About 15  candidates after cut

CBM Collaboration meeting


Hyperon simulations

Optimised cut parameters, -

Statistics: 8∙105 events

CBM Collaboration meeting


Hyperon simulations

Optimised cut parameters, -

Statistics: 5.8∙105 events

CBM Collaboration meeting


Invariant mass distributions after cuts

Invariant mass distributions after cuts

--

CBM Collaboration meeting


Reconstruction of initial spectra

Reconstruction of initial spectra

Initial spectrum, 

Reconstructed spectrum, 

CBM Collaboration meeting


Reconstructed distributions

Reconstructed distributions 

y = 1.0 – 1.2

y = 1.8 – 2.0

Yield UrQMD: 40.5

Yield reconstructed: 40.3

Statistics: 104 events

CBM Collaboration meeting


Reconstructed distributions1

Reconstructed distributions -

y = 1.2 – 1.4

y = 1.8 – 2.0

Yield UrQMD: 0.98

Yield reconstructed: 0.95

Statistics: 8∙105 events

CBM Collaboration meeting


Future steps

Further cut optimisation

Simulations with realistic track finding

Study the influence of mass and topological constraints on the momentum and invariant mass resolution

Acceptance vs magnetic field analysis

Future steps

CBM Collaboration meeting


  • Login