Elastic Neural Net for standalone RICH ring finding Sergey Gorbunov Ivan Kisel DESY, Zeuthen KIP,...
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Transcript of Elastic Neural Net for standalone RICH ring finding Sergey Gorbunov Ivan Kisel DESY, Zeuthen KIP,...
Elastic Neural Net Elastic Neural Net for standalone RICH ring for standalone RICH ring
findingfinding
Sergey Gorbunov Ivan KiselSergey Gorbunov Ivan Kisel
DESY, Zeuthen KIPDESY, Zeuthen KIP, Uni-Heidelberg, Uni-Heidelberg KIPKIP
ACAT 2005, DESY, ZeuthenMay 22-27, 2005
ACAT05 DESY, ZeuthenACAT05 DESY, Zeuthen S. Gorbunov, I. KiselS. Gorbunov, I. Kisel 22
EN – Traveling Salesman ProblemEN – Traveling Salesman Problem
Discrete ENDiscrete EN
(*) Pentium IV/2.4 GHz(*) Pentium IV/2.4 GHz Nature, 326 (1987) 689
ACAT05 DESY, ZeuthenACAT05 DESY, Zeuthen S. Gorbunov, I. KiselS. Gorbunov, I. Kisel 33
EN – Ring Search : IdeaEN – Ring Search : Idea
CHEP’01, Beijing (2001) 162
Features:• External forces -
minimizing distances• Internal forces -
constraint on Fourier coefficients
ACAT05 DESY, ZeuthenACAT05 DESY, Zeuthen S. Gorbunov, I. KiselS. Gorbunov, I. Kisel 44
EN – Ring Search : ImplementationEN – Ring Search : Implementation
Scheme:• Loop over hits• Finding a ring in a local area around
the hit• Sorting of the found rings
Details:• No internal forces - fixed ring shape
(circle)• External forces - minimize distances• Discrete ring evolution - direct finding
of the minimum in 2-3 iterations • Time ~ total number of hits
ACAT05 DESY, ZeuthenACAT05 DESY, Zeuthen S. Gorbunov, I. KiselS. Gorbunov, I. Kisel 55
RICH Detector in the CBM Experiment at GSIRICH Detector in the CBM Experiment at GSI
beam
2 m
mirror
R = 450 cm
gaseous radiator
40%He + 60%CH4N2
3.3
m
4.7
m
1 central Au+Au collision, 25 AGeV (UrQMD)
38 rings/event
33 electrons
5 pions
12.6 e from primary vertex
5 from primary vertex
ACAT05 DESY, ZeuthenACAT05 DESY, Zeuthen S. Gorbunov, I. KiselS. Gorbunov, I. Kisel 66
EN – PerformanceEN – Performance
All set: N hits ≥ 5Ref set: N hits ≥ 15Extra set: 5 ≤ N hits < 15Reconstructed: ≥ 70% hits from the same MCClone: MC reconstructed few timesGhost: < 70% hits from the same MC
ACAT05 DESY, ZeuthenACAT05 DESY, Zeuthen S. Gorbunov, I. KiselS. Gorbunov, I. Kisel 77
ConclusionConclusion
• Efficient Efficient ring finder based on the elastic net• StandaloneStandalone – no track guidance necessary• SimpleSimple – suitable for hardware implementation• FastFast – can be used for triggering