hyperon simulations
Download
Skip this Video
Download Presentation
Hyperon simulations

Loading in 2 Seconds...

play fullscreen
1 / 19

Hyperon simulations - PowerPoint PPT Presentation


  • 93 Views
  • Uploaded on

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)

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Hyperon simulations' - ruana


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

slide3
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

cut parameter distributions
Cut parameter distributions

Distance of closest approach

Impact parameter for positive tracks

All pairs

All positive

protons

 pairs

CBM Collaboration meeting

slide11
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

slide13
Optimised cut parameters, -

Statistics: 8∙105 events

CBM Collaboration meeting

slide14
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

ad